Syringoma

Introduction

Background

Syringoma is a benign adnexal neoplasm formed by well-differentiated ductal elements. Its name is derived from the Greek word syrinx, which means pipe or tube.

Pathophysiology

Syringoma is a benign neoplasm, which is traditionally considered to differentiate along eccrine lines.

Enzyme immunohistochemical tests demonstrate the presence of eccrine enzymes such as leucine aminopeptidase, succinic dehydrogenase, and phosphorylase. The immunohistochemical pattern of cytokeratin expression indicates differentiation toward both the uppermost part of the dermal duct and the lower intraepidermal duct (ie, sweat duct ridge). However, sometimes distinguishing between eccrine and apocrine ducts is difficult and many tumors that were traditionally thought to be eccrine have recently been shown to have apocrine differentiation. Electron microscopy demonstrates ductal cells with numerous short microvilli, desmosomes, luminal tonofilaments, and lysosomes. The histogenesis of syringomas is most likely related to eccrine elements or pluripotential stem cells.

Some investigators have suggested that cases of eruptive syringoma may represent a hyperplastic response of the eccrine duct to an inflammatory reaction rather than a true adnexal neoplasm. In this setting, they propose the term syringomatous dermatitis for such cases. Likewise, the scalp "syringomas" seen in scarring alopecia represent a reactive proliferation in response to the fibrosis.

Frequency

International

Syringomas are fairly common lesions.

Mortality/Morbidity

These benign tumors are largely of cosmetic significance.

Sex

Females are affected more often than males.

Age

These tumors usually first appear at puberty; additional lesions can develop later.

Clinical

History

• The lesions are asymptomatic.
• Rarely, the patient may have a family history of similar lesions. Rarely, syringomas may be associated with the Brooke-Spiegler syndrome, an autosomally dominant disease characterized by the development of multiple cylindromas, trichoepitheliomas, and occasional spiradenomas.
• Syringomas may be associated with Down syndrome.

Physical

Appearance of lesions

• Syringomas are skin-colored or yellowish, small, dermal papules (see Media File 1).
• Sometimes, the lesions may appear translucent or cystic.
• The surface can be rounded or flat-topped.
• The lesions are usually smaller than 3 mm in diameter.
• Eruptive syringomas commonly appear as hyperpigmented papules on the chest or penile shaft.

Distribution of lesions

• The lesions are usually multiple, arranged in clusters, and symmetrically distributed.
• Most commonly, lesions are limited to the upper parts of the cheeks and lower eyelids.
• Other common sites include the axilla, chest, abdomen, penis, and vulva.
• In the variant of eruptive syringoma, multiple lesions appear simultaneously, typically on the chest and lower abdomen.
• Rarely, syringomas appear as unilateral linear nevoid lesions.

Differential diagnoses and related conditions

• In rare instances, scalp syringomas can produce scarring alopecia.
• On occasion, syringomas can be associated with milia and vermiculate atrophoderma.
• Clinically, syringomas on the face are must be distinguished from trichoepitheliomas and basal cell carcinomas.
• Lesions on the eyelids may be confused with xanthelasma.
• Eruptive syringomas on the trunk can resemble disseminated granuloma annulare.

Causes

• Syringomas are frequently incidental, although some familial cases may occur.
• Eruptive syringomas (see Media File 2) are more common in African Americans and Asians than in other patients.
• Syringomas can be associated with Down syndrome.
• Clear-cell syringomas may be associated with diabetes mellitus.

Read More......

Pilomatrixoma

Introduction

Background

A pilomatrixoma is a benign appendageal tumor with differentiation toward hair cells. It usually manifests as a solitary, asymptomatic, firm nodule. It has long been considered a rare tumor, but it may be more common than previously realized. It is more common in children, but occurrence in adults is increasingly being recognized. Recommended treatment is surgical excision. Multiple pilomatrixomas have been observed, mainly in association with myotonic dystrophy. Pilomatrix carcinoma is a rare condition.

Pathophysiology

In one study of 10 pilomatrixoma lesions, all immunostaining results were strongly positive for BCL2.³⁸ This is a proto-oncogene that helps suppress apoptosis in benign and malignant tumors; these data suggest that faulty suppression of apoptosis contributes to the pathogenesis of these tumors.

More recently, investigators have demonstrated that the proliferating cells of human pilomatrixomas show prominent staining with antibodies directed against LEF-1 (a marker for hair matrix cells). Evidence also indicates that S100 proteins can be used as biochemical markers in characterization of pilomatrixomas.³⁹ These data provide biochemical support of morphological evidence that these tumors are derived from hair matrix cells. Furthermore, investigators have shown that at least 75% of persons with pilomatrixomas who have examined have mutations in the gene CTNNB1; these data directly implicate beta-catenin/LEF misregulation as the major cause of hair matrix cell tumorigenesis in humans.^40,41,42

Frequency

United States

Pilomatrixomas have long been considered uncommon cutaneous tumors; however, they may be more common than is realized, especially in children and young adults. In one American dermatopathology laboratory, pilomatrical neoplasms were considered the most common solid cutaneous tumors in patients aged 20 years or younger.

International

In one dermatopathology laboratory in the United Kingdom, pilomatrixomas accounted for 1 in 500 histologic specimens. Investigators found 37 cases published in Japanese dental journals between 1977 and 1994.⁴³ In Turkey, 15 patients were seen in a pediatric surgery clinic from 1984-1994.³ In France, a retrospective study of records in one surgery clinic revealed 33 patients who had undergone surgery for pilomatrixomas between 1989 and 1997.⁴

Mortality/Morbidity

Pilomatrixomas are not associated with mortality. Very large tumors (£ 18 cm) can cause considerable discomfort but are uncommon. Pilomatrix carcinomas are also uncommon, but they are locally invasive and can cause visceral metastases and death.

Race

Most reported cases have occurred in white persons. Whether this represents publication bias or a true racial predisposition is unclear.

Sex

Most studies report a slight preponderance in females. In one retrospective study of 209 cases, the female-to-male ratio was 1.5:1.

Age

Most reported cases have occurred in children. Lesions are often discovered in the first 2 years of life; however, in a retrospective study of 209 cases published in 1998, investigators found the age of presentation showed a bimodal pattern, with the first peak being 5-15 years and the second being 50-65 years.⁴⁴

Clinical

History

• Patients usually present with a solitary nodule that has been slowly growing over several months or years.
• Patients are usually asymptomatic, but some report pain during episodes of inflammation or ulceration.
• Rapid growth is rare, but reports indicate one lesion reaching 35 mm in 8 months and another reaching 1 cm in 2 weeks.
• Occurrence in more than one member of the same family is rare and is usually observed in association with myotonic dystrophy.

Physical

• Approximately 50% of the lesions occur on the head and neck, especially the cheek, preauricular area, eyelids, forehead, scalp, and lateral and posterior neck.^45,46,47
  • Lesions can also occur on the upper and lower extremities and trunk.⁴⁸
  • One lesion was observed in the middle ear and another in the ovary.^49,50
• Most lesions measure 0.5-3 cm, but, rarely, giant lesions up to 15 cm are reported.
• Patients usually have a single, firm, stony, hard nodule.
• Lesions are usually the color of the normal skin, but reddish-purple lesions have been observed (probably resulting from hemorrhage).
• Stretching of the overlying skin can give the lesion a multifaceted, angulated appearance known as the "tent sign," likely due to calcification in the lesion.
• One lesion showed the "dimple sign," which is often associated with dermatofibromas.
• Unusual morphological variants include perforating, cystic, bullous, lymphangiectatic, hornlike, keratoacanthomalike, pigmented, and lesions that show anetodermalike changes on the surface.^{51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67}

Causes

Investigators in one study showed that at least 75% of the lesions studied had mutations in the gene CTNNB1; these data directly implicate beta-catenin/LEF misregulation as the major cause of hair matrix cell tumorigenesis in humans.

Read More......

Mucous Cyst

Introduction

Background

A mucous cyst (MC) is a benign, common, mucus-containing cystic lesion of the minor salivary glands in the oral cavity. Some authors prefer the term mucocele since most of these lesions are not true cysts in the absence of an epithelial lining. The lesions can be located directly under the mucosa (superficial mucocele), in the upper submucosa (classic mucocele), or in the lower corium (deep mucocele). Two types of MCs occur based on the histologic features of the cyst wall: a mucous extravasation cyst formed by mucous pools surrounded by granulation tissue (92%) and a mucous retention cyst with an epithelial lining (8%).

Pathophysiology

The mechanism of formation of the MC is not totally clear; however, a traumatic etiology rather than an obstructive phenomenon is favored. Chaudhry et al showed that the escape of mucus into the surrounding tissue after severing the excretory salivary ducts led to the formation of the MC. The frequent location of the MC in the lateral aspect of the lower lip also supports the role of trauma as an etiologic factor. Although obstruction may play a role in the etiology of the MC, Chaudhry et al demonstrated that the ligation and cutting of the salivary glands' ducts in mice and rats did not create the MC.

Frequency

United States

The prevalence of an oral MC is 2.5 lesions per 1000 population.

Mortality/Morbidity

This benign condition is self-limited in most cases.

Race

A MC is most frequent in whites.

Sex

The sexual incidence is about equal.

Age

Although patients of all ages can be affected, more than one half of MC cases occur in those younger than 30 years. Mucous retention cysts are more frequent in older persons than in younger persons.

Clinical

History

The clinical presentation varies by the type and the location of the lesion.

• People with superficial MCs may complain of single or multiple blisters that often spontaneously burst, leaving shallow ulcers.
  • These lesions completely heal in a period of a few days.
  • Sometimes, lesions recur in the same site.
• The classic MC presents as a shiny, dome-shaped papule that waxes and wanes over several months.
• An MC located in the deep soft tissue has a slow growth phase, resulting in a firm, deep mass.
• Rare cases have been described in the neck arising from ectopic salivary glands; these lesions are associated with cheilitis glandularis apostematosa.

Physical

The clinical presentation depends on the depth of the lesion.

• Superficial MC
  • The mucus accumulates immediately below the mucosa, resulting in small translucent vesicles (0.1-0.4 cm in diameter) in the soft palate, the retromolar region, and the buccal mucosa.
  • In time, these blisters burst spontaneously or by trauma, leaving shallow ulcers or erosions.
• Classic MC
  • This form presents as a collection of mucous material in the upper submucosa producing a well-defined, mobile, and painless dome-shaped swelling.
  • These lesions often exhibit a smooth, blue surface.
  • The size varies from a few millimeters to several centimeters in diameter, but 75% of the lesions are smaller than 1 cm in diameter.
  • Eventually, the surface of the lesion turns irregular and whitish due to multiple cycles of rupture and healing caused by trauma or puncture.
  • The most frequent locations are in the lower lip, the floor of the mouth, the cheek, the palate, the retromolar fossa, and the dorsal surface of the tongue; however, these lesions spare the upper lip.
  • Most of the larger lesions commonly affect the floor of the mouth; these are called ranula because of the similarity to the throat pouch of frogs. This collection of mucus can extend beyond the oral cavity and as far as the upper mediastinum or skull base.
  • When the mucus accumulates in the deep soft tissues, the presentation is of an enlarging, painless mass assuming the pink coloration of the mucosa.

Causes

A traumatic etiology is favored. Animal models and the location of these lesions in areas of high traumatic exposure support this theory.

Read More......

Mastocytosis

Introduction

Background

Mastocytosis is a disorder characterized by mast cell proliferation and accumulation within various organs, most commonly the skin.

The World Health Organization (WHO) classification of mastocytosis includes the following^1,2 :

• Cutaneous mastocytosis
  • Urticaria pigmentosa
  • Maculopapular cutaneous mastocytosis
  • Diffuse cutaneous mastocytosis
  • Mastocytoma of skin
• Indolent systemic mastocytosis
• Systemic mastocytosis with an associated (clonal) hematologic non–mast cell lineage disease
• Aggressive systemic mastocytosis
• Mast cell leukemia
• Mast cell sarcoma
• Extracutaneous mastocytoma^1,2

This article focuses on cutaneous mastocytosis (CM). Types of CM include solitary mastocytoma, diffuse erythrodermic mastocytosis, paucicellular mastocytosis (also termed telangiectasia macularis eruptiva perstans [TMEP]), and urticaria pigmentosa (UP). UP is the most common form and is characterized by oval or round red-brown macules, papules, or plaques ranging in number from a few to thousands (see Media Files 1-2). Lesions may vesiculate in infancy (see Media File 3).

When a UP or mastocytoma lesion is stroked, it typically urticates, becoming pruritic, edematous, and erythematous. This change is referred to as the Darier sign, which is explainable on the basis of mast cell degranulation induced by physical stimulation. Uncontrolled stroking of mastocytomas should be avoided in patients who have had a systemic reaction such as miosis and asthmalike symptoms in their past.³

Pathophysiology

Whether mastocytosis is a hyperplastic reaction to an unknown stimulus or whether it is a neoplastic condition is unknown. Increased local concentrations of soluble mast cell growth factor in lesions of CM are believed to stimulate mast cell proliferation, melanocyte proliferation, and melanin pigment production. The induction of melanocytes explains the hyperpigmentation that commonly is associated with cutaneous mast cell lesions. Impaired mast cell apoptosis has been postulated to be involved, as evidenced by up-regulation of the apoptosis-preventing protein BCL-2 demonstrated in patients with mastocytosis. Activating mutations of the proto-oncogene c-kit have been identified but do not explain the initiation of the disease.⁴ Interleukin 6 levels have been shown to be elevated and correlated with disease severity, indicating interleukin 6 is involved in the pathophysiology of mastocytosis.⁵

Associated systemic manifestations are believed to reflect the release of mast cell–derived mediators, such as histamine, prostaglandins, heparin, neutral proteases, and acid hydrolases. Symptoms and signs induced by mediators may include headache, flushing, dizziness, tachycardia, hypotension, syncope, anorexia, nausea, vomiting, abdominal pain, and diarrhea. The skeletal, hematopoietic, gastrointestinal (GI), cardiopulmonary, and central nervous systems may be involved either directly, via mast cell infiltration, or indirectly, via mast cell mediator release.

Frequency

United States

Of new patients visiting dermatology clinics, 0.1-0.8% have some form of mastocytosis.

International

The international incidence is not known to differ from the incidence observed in the United States.

Mortality/Morbidity

Most cases of UP in children resolve spontaneously, although acute extensive degranulation rarely can cause life-threatening episodes of shock. Patients with adult- or adolescent-onset UP are more likely to have persistent disease and are at greater risk for systemic involvement. Juvenile-onset systemic mastocytosis has a malignant transformation rate as high as 7%, while adult-onset systemic mastocytosis has a malignant transformation rate as high as 30%.

Race

Most reported cases are in whites. The cutaneous lesions of most types of mastocytosis are less visible in persons with more heavily pigmented skin.

Sex

Mastocytosis affects males and females equally (no known sex predilection).

Age

Most patients with mastocytosis are children; 75% of cases occur during infancy or early childhood. Incidence peaks again in patients aged 30-49 years.

Clinical

History

Patients may present with cutaneous lesions, systemic symptoms of an acute nature, and/or chronic systemic symptoms.

• Most patients have pruritic cutaneous lesions.
• Some patients, especially those with extensive cutaneous disease, experience acute systemic symptoms exacerbated by certain activities or ingestion of certain drugs or foods. Possible systemic symptoms include flushing, headache, dyspnea, wheezing, rhinorrhea, nausea, vomiting, diarrhea, and syncope.
• Patients also may have chronic systemic symptoms involving various organ systems.
  • Involvement of the skeletal system may be manifested as bone pain or the new onset of a fracture.
  • Involvement of the central nervous system may produce neuropsychiatric symptoms, as well as nonspecific changes such as malaise and irritability.
  • GI involvement may yield weight loss, diarrhea, nausea/vomiting, and abdominal cramps.
  • Cardiovascular effects can include shock, syncope (resulting from vascular dilatation), or angina.
  • Anaphylactic reactions to hymenoptera stings may be the first sign of mastocytosis.

Physical

The most common physical findings in mastocytosis involve the skin, liver, spleen, and cardiovascular system.

• Skin - Lesion types
• Macules, papules, nodules, and plaques (see Media File 4)
• Blisters and bullae in children (see Media File 5)
• Diffuse induration
• Isolated nodule or tumor
• Skin - Distribution
• Widespread symmetric distribution
• Trunk involved more than extremities
• Tendency to spare the face, scalp, palms, and soles; however, a patient with scarring alopecia has been reported⁶
• Skin - Lesion color, quantity, and size
• Yellow-tan to red-brown
• From 1 to more than 1000
• From 1 mm to several centimeters
• Skin - Special characteristics
• Darier sign: Wheal and surrounding erythema develop in a lesion after rubbing it.
• Dermatographism: In approximately half the patients, stroking macroscopically uninvolved skin produces dermographia.
• Flushing: Flushing may occur spontaneously following skin stroke or after ingesting a mast cell degranulating agent.
• Liver - Possible hepatomegaly (present in 40% of adult patients with systemic mastocytosis)
• Spleen - Possible splenomegaly (present in 50% of patients with systemic mastocytosis)
• Cardiovascular - Hypotension and tachycardia

Causes

Mastocytosis probably is a hyperplastic response to an abnormal stimulus. Rare cases of familial UP have been recorded.⁷

Read More......

Epidermal Inclusion Cyst

Introduction

Background

Several different terms have been used to describe epidermal cysts. Epidermal inclusion cyst refers to those cysts that are the result of the implantation of epidermal elements in the dermis. However, many cysts originate from the infundibular portion of the hair follicle, and the more general term, epidermoid cyst, is favored. Milia merely represent miniature epidermoid cysts. The term wen should be reserved for trichilemmal or pilar cysts. Sebaceous cyst is a misnomer, and the term should not be used at all because these cysts are not of sebaceous origin.

Pathophysiology

Epidermoid cysts result from the proliferation of epidermal cells within a circumscribed space of the dermis. They have been shown to not be of sebaceous origin based on the analysis of their lipid pattern, which demonstrates similarities to the epidermis. In addition, epidermoid cysts express cytokeratins 1 and 10, which are constituents of the suprabasilar layers of the epidermis. The source of this epidermis is often the infundibulum of the hair follicle, as evidenced by the observation that the lining of the 2 structures is identical.

Inflammation is in part mediated by the horny material contained in epidermoid cysts. Extracts of this material have been shown to be chemotactic for polymorphonucleocytes.

The manner in which carcinomas may rarely arise within epidermoid cysts is unknown. In a series of epidermoid cysts with carcinoma, immunohistochemical results for human papillomavirus (HPV) were negative, leading the authors to conclude that HPV is not likely to be the cause of squamous cell carcinomas (SCCs) in these cysts. Some have proposed that repetitive trauma and inflammation may play a role.

Mortality/Morbidity

• Epidermoid cysts grow slowly and usually do not cause symptoms, but they may become inflamed or secondarily infected, resulting in pain and tenderness.
• Rarely, malignancies, including basal cell carcinoma, Bowen disease, SCC, and even mycosis fungoides, have developed in epidermoid cysts.

Sex

In one study, epidermoid cysts were approximately twice as common in men as in women.

Age

Epidermoid cysts may occur at any time in life, but they are most common in the third and fourth decades of life. Gardner syndrome is an exception; the average patient age at onset is 13 years.

Clinical

History

• Discharge of a foul-smelling cheeselike material is a common complaint.
• Less frequently, the cysts can become inflamed or infected, resulting in pain and tenderness.
• In the uncommon event of malignancy, rapid growth, friability, and bleeding have been reported.
• When located orally, the cysts can cause difficulty in breathing, swallowing, or even speaking.
• Lesion of the genitals can be especially painful during intercourse and cause problems with walking or wearing underwear. They can also interfere with urination.
• Subungual lesions have also been associated with pain, as have plantar lesions, causing difficulty with walking or other activities.

Physical

Epidermoid cysts appear as firm, round, mobile, flesh-colored to yellow or white subcutaneous nodules of variable size. A central pore or punctum is an inconsistent finding that may tether the cyst to the overlying epidermis and from which a thick cheesy material can sometimes be expressed. In individuals with dark pigmentation, epidermoid cysts may also be pigmented. In a study of Indian patients with epidermoid cysts, 63% of the cysts contained melanin pigment.

• In one study, epidermoid cysts were most common (in descending order of frequency) on the face, the trunk, the neck, the extremities, and the scalp. While facial involvement is also frequent in Gardner syndrome, the extremities tend to be affected more than the trunk. The Ibos of Nigerian and other cultures who practice female circumcision represent special groups of patients in whom the vulva is the most common site.
• Epidermoid cysts of the genitals are also common in the general population and may appear as a mass in the breast, the vulva, the clitoris, the penis, the scrotum, or the perineum. For one woman, a clitoral cyst present from age 12 years resulted in ambiguous genitalia. The ocular and oral mucosae can also be affected, and cysts have been reported on the palpebral conjunctivae, on the lips, on the buccal mucosa, on and under the tongue, and even on the uvula.
• Epidermoid cysts manifest in various ways on the extremities. When the cysts occur subungually, they can cause changes in the nails, such as onycholysis and subungual hyperkeratosis, which may be mistaken for psoriasis or onychomycosis. Furthermore, epidermoid cysts on the distal portions of the digits may extend into the terminal phalanx. These cysts also produce changes in the nails, such as pincer nails, in addition to erythema, edema, tenderness, and pain. Sometimes, these findings can mimic arthritis. Palmoplantar lesions represent a unique subset of epidermoid cysts.
• The anterior fontanelle, umbilicus, and popliteal fossa are unusual locations where epidermoid cysts have been found.

Causes

Epidermoid cysts likely form by several mechanisms. They may result from the sequestration of epidermal rests during embryonic life, occlusion of the pilosebaceous unit, or traumatic or surgical implantation of epithelial elements. HPV infection and eccrine duct occlusion may be additional factors in the development of palmoplantar epidermoid cysts. HPV has also been identified in nonpalmoplantar epidermoid cysts.

• Congenital epidermoid cysts of the anterior fontanelle or those that are orogenital in location presumably result from sequestration or trapping of epidermal rests along embryonic fusion planes during development. Lip and lingual lesions may be related to aberrant fusion of the branchial arches, and genital lesions could result from improper closure of the genital folds.
• Any benign or malignant process affecting or growing near the pilosebaceous unit may lead to occlusion or impingement of the follicular ostia and subsequent formation of a cyst. Many cysts with an acneiform distribution are probably the result of follicular occlusion. In elderly persons, accumulated sun damage can injure the pilosebaceous unit, thus causing abnormalities, such as comedonal plugging and hypercornification, both of which can eventuate in cyst formation. Alternatively, cases of mycosis fungoides, Bowen disease, molluscum contagiosum, seborrheic keratoses, and nevi have all been reported in association with epidermoid cysts. In each case, the process was growing in and around the hair follicle.
• True epidermal cysts result from the implantation of epithelial elements in the dermis.
  • Injuries, especially of the crushing type, such as the slamming of a car door on a finger, are frequently reported in association with subungual or terminal phalanx epidermoid cysts.
  • As previously mentioned, female circumcision is associated with the formation of epidermoid cysts, perhaps from instruments that are not sharp or from imprecise cutting.
  • Theoretically, any surgical procedure may result in epidermoid cysts, and it is surprising that they are not a more common occurrence. Unusual examples of this mechanism include the formation of multiple epidermoid cysts after rhinoplasty and reduction mammoplasty. The use of dermal grafts, presumably because of the inclusion of epithelial elements, has also resulted in the formation of epidermoid cysts. A similar situation has been observed with the use of myocutaneous flaps where the cutaneous portion is buried. Even seemingly minor procedures, such as needle biopsy of the breast, have reportedly induced epidermoid cysts.
• The origin of palmoplantar cysts is especially controversial, and their etiology may be unique. This idea is based on the discovery of HPV and eccrine structures within these cysts. In addition, the palms and the soles lack the pilosebaceous units present in other parts of the body. Some have also questioned the role of daily minor foot trauma, while others implicate all 3 factors.
  • Numerous reports have documented HPV types 57 and 60 antigens, as well as histologic changes characteristic of wart infection, in epidermoid cysts. These findings have been found more consistently in plantar cysts than in palmar cysts, and HPV type 60 has been identified more frequently than type 57. Although most patients deny a history of trauma, many of these cysts are located over pressure points, and mechanical pressure or minor trauma may be a contributing factor. In one study of 25 plantar epidermoid cysts, all were located on weight-bearing areas. The theory is that trauma introduces wart virus into the epidermis and that mechanical pressure forces the wart and the epidermis to descend into the dermis. Subsequently, the wart induces epithelial proliferation that may result in the formation of cysts. On the other hand, the presence of HPV in epidermoid cysts may merely represent superinfection.
  • Carcinoembryonic antigen–positive ductal structures in conjunction with HPV have been found in plantar epidermoid cysts. Some authors speculate that HPV may preferentially infect acrosyringeal epithelium and then invade dermal eccrine ducts, inducing the formation of cysts. In fact, connections between the eccrine dermal duct and epidermoid cysts have been characterized with 3-dimensional reconstruction analysis. Others dispute the notion that epidermoid cysts (at least palmar ones) are of eccrine origin in light of a study in which palmar epidermoid cysts failed to react with antibodies specific to luminal and secretory cells of lesions in eccrine glands. Instead, immunoreactivity to differentiation-specific cytokeratins (1 and 10) identical to those of the suprabasal layers of the epidermis and follicular infundibulum occurred. The authors of this study concluded that palmar epidermal cysts with HPV infection are not of eccrine origin, but that they are the result of epidermal implantation or trauma. Another explanation that has been proposed, however, is that these findings reflect metaplasia of the eccrine duct epithelium.
• Certain hereditary syndromes have epidermoid cysts as part of their features. Examples include Gardner syndrome, basal cell nevus syndrome, and pachyonychia congenita. In addition, idiopathic scrotal calcinosis may actually represent an end stage of dystrophic calcification of epidermoid cysts in that area of the body.
  • In a study of 39 patients with Gardner syndrome, 13 (33%) had at least 1 epidermoid cyst. The number of lesions varied from 1 to 20, and the average was 4. Of significance, in another study, epidermoid cysts occurred before polyps were detectable in 39 (53%) of 74 patients with Gardner syndrome. Pilomatrical differentiation may be present in portions of the cysts in these patients. A distinct syndrome with colonic polyps and epidermoid cysts has also been described, where patients had malignant brain tumors and lacked the soft-tissue abnormalities seen in Gardner syndrome.
  • An epidermoid cyst may be a feature of pachyonychia congenita. In addition, a syndrome of leukonychia totalis, multiple epidermoid cysts, and renal calculi has been reported.
  • As the name implies, the etiology of idiopathic scrotal calcification is unknown. However, some authors view this condition as an end stage of dystrophic calcification of scrotal epidermoid cysts. This hypothesis is based on the histologic observation of squamous linings surrounding calcified masses. The lining or wall is not always seen because biopsy specimens are often from older lesions where inflammation has destroyed it.

Read More......

Dermatofibroma

Introduction

Background

Dermatofibroma (DF) is a common cutaneous nodule of unknown etiology that occurs more often in women. The lesion frequently develops on the extremities (mostly the lower legs) and is usually asymptomatic, although pruritus and tenderness are not uncommon. The latter feature is seen in a sufficient number of patients to make DF the most prevalent of all painful skin tumors. A number of well-described, histologic subtypes have been reported. Removal of the tumor is not necessary unless diagnostic uncertainty exists or particularly troubling symptoms are present.

Pathophysiology

The precise mechanism for the development of DF is unknown. Rather than a reactive tissue change, DF seems more likely to be a neoplastic process because of the persistent nature of the lesion and the demonstration that it is a clonal proliferative growth.¹ Clonality, of course, by itself, is not necessarily synonymous with a neoplastic process; it has been demonstrated in inflammatory conditions, including atopic dermatitis, lichen sclerosis, and psoriasis.

Immunohistochemical testing with antibodies to factor XIIIa is frequently positive in DF, while antibodies to MAC 387 show less consistent results. The former antibody labels fibroblasts (dermal dendrocytes), while the latter labels monocyte-derived macrophages (histiocytes). Controversy exists as to whether the factor XIIIa positivity occurs within the actual tumor cells of DF or simply labels the reactive stromal cells; hence, the cell of origin for the spindle cell proliferation of DF is debatable. The cell surface proteoglycan, syndecan-1, may play a role in the growth of DF.² Transforming growth factor-beta signaling might be a trigger of the fibrosis seen in DF.³

Frequency

United States

DF is relatively common.

International

Incidence is probably similar to that in the United States.

Mortality/Morbidity

DF is regarded as a benign lesion; however, discomfort from pain or itching may be significant. The few case reports of metastatic DF are disputable from the standpoint of histologic diagnosis. Such reported lesions were highly cellular, of large size, and locally recurrent.⁴ Indolent pulmonary metastases also were observed.

Race

Frequency appears to be similar in all races.

Sex

Females are affected more commonly than males, with a male-to-female ratio of 1:4.

Age

DF can occur in patients of any age, but it usually develops in young adulthood. Approximately 20% of the lesions occur before age 17 years.

Clinical

History

Dermatofibromas typically arise slowly and most often occur as a solitary nodule on an extremity, particularly the lower leg, but any cutaneous site is possible. Several lesions may be present, but only rarely are multiple (ie, 15 or more) tumors found. This multiple variant is seen most frequently in the setting of autoimmune disease or altered immunity, such as systemic lupus erythematosus, HIV infection, or leukemia and may be indicative of worsening immunoreactivity. Mild regression has been reported with clinical improvement of the underlying disorder. Conversely, drugs to treat the underlying disorders have also been implicated in causation. Multiple clustered DFs also have been reported.⁵ Patients may describe a hard mole or unusual scar and may be concerned about the possibility of skin cancer.

DFs are characteristically asymptomatic, but itching and pain often are noted. They are the most common of all painful skin tumors.⁶ Women who shave their legs may be bothered by the razor traumatizing the lesion in that region, causing pain, bleeding, erosive changes, and ulceration. Although cases of unusually rapid growth exist, most DFs remain static for decades or persist indefinitely. Uncommon reports describe spontaneous regression,⁷ and this may yield postinflammatory hypopigmentation.

Physical

Typically, the clinical appearance is a solitary, 0.5- to 1-cm nodule. A sizable minority of patients may have several lesions, but rarely are more than 15 lesions present. The overlying skin can range from flesh to gray, yellow, orange, pink, red, purple, blue, brown, or black, or a combination of hues (see Media File 1). On palpation, the hard nodule may feel like a frozen pea or a small pebble fixed to the skin surface and is freely movable over the subcutis. Tenderness may be elicited with manipulation of the lesion.

The characteristic tethering of the overlying epidermis to the underlying lesion with lateral compression, called the dimple sign, may be a useful clinical sign for diagnosis.⁸ The dimple sign is not unique to DF, and dermatoscopy may be useful in supporting the clinical impression.⁹

The extremities are the most common sites of involvement, particularly the lower legs. Although any cutaneous site can be seen, palm and sole involvement is rare. Giant (>5 cm in diameter), atrophic, atypical polypoid and DF with satellitosis variants have been reported.

Causes

Historically attributed to some traumatic insult to the skin (eg, arthropod bite), the cause of DF is unknown. Because of its persistent nature, DF is probably better categorized as a neoplastic process rather than a reactive tissue change. A study of eruptive DFs in a kindred suggests that a genetic component may exist.¹⁰

Read More......

Binge eating

Definition

Binge eating is a disorder characterized by eating more than a person needs to satisfy hunger.

Alternative Names

Eating - binge

Considerations

The eating disorder bulimia is most common among female adolescents or young adults. People with bulimia typically consume large quantities of easily ingested high-calorie foods, usually in secrecy. This binge eating is usually followed by self-induced vomiting and accompanied by feelings of guilt or depression.

Complications resulting from prolonged bulimia include gastric dilatation, pancreatitis, dental decay, pharyngitis, esophagitis, pulmonary (lung) aspiration, and electrolyte abnormalities. Constipation and hemorrhoids are also common in people with bulimia.

Although death from bulimia is rare, the long-term outcome in severe bulimia can be worse than the outcome in anorexia nervosa, which suggests that the psychiatric disorder that causes bulimia is usually more severe.

Causes

While binge eating often begins during or after strict dieting, and may be caused by stress related to insufficient food intake, its cause remains unknown.

Home Care

Take measures to reduce stress and improve overall health.

Medication is usually not necessary for this disorder. However, antidepressants, as prescribed by a doctor, are often helpful. Supportive care and counseling are recommended. Individual, group, family, and behavioral therapy may provide some help.

When to Contact a Medical Professional

• bulimia is suspected

What to Expect at Your Office Visit

The health care provider will perform a physical examination. A history of the person's eating patterns may be sought from one or more family members because the person may not acknowledge that they are binge eating.

Medical history questions documenting binge eating in detail may include:

• How long has this been occurring?
• Are "purge" behaviors (such as self-induced vomiting or laxative abuse) also present?
• What other symptoms are also present?

Possible diagnostic tests include blood studies, such as electrolyte levels.

INTERVENTION

Behavior is usually controlled with counseling, biofeedback training (a process of monitoring body functions and altering these functions through relaxation), and individual or group psychotherapy.

References

Schmidt U, Lee S, Beecham J, et al. A randomized controlled trial of family therapy and cognitive behavior therapy guided self-care for adolescents with bulimia nervosa and related disorders. Am J Psychiatry. 2007;164:591-598.

Read More......