A PIGMENTED NODULE WITH BLEEDING

The patient is a 47 year old woman who complains of a nodule on the buttock growing for the last year and bleeding for the last 2 weeks.  Examination shows a 1.8 cm lesion with variable pigmentation, an irregular border, and a raised ulcerated nodular component measuring approximately 1.0 cm.  An excisional biopsy was performed.     Diagnosis:  Malignant melanoma. Microscopic Description:  Sections stained with the H&E stain…

A PAINFUL UMBILICAL NODULE

The patient is a 26 year old female with history of umbilical pain, cyclical with menstrual cycle, and with some cyclical discharge. Examination reveals two pink nodules in the umbilicus. A biopsy is performed. Diagnosis: Cutaneous endometriosis. Discussion: Cutaneous endometriosis is a subset of extrapelvic endometriosis presenting at a mean age of 34 years and represents 8.9% of reported cases of endometriosis. The most common presentations are a nodu…

ALOPECIA WITH BLACK DOTS

The patient is a 54 year old female who presents with alopecia. Clinical exam reveals black dots on her scalp with scale, pustules and erythema. She also has areas of scarring alopecia. Diagnosis: Black dot tinea. Discussion: Black dot tinea capitis is a form of dermatophytosis primarily affecting the hair shaft and hair follicle. It is also sometimes called ringworm of the scalp or tinea tonsurans, because Tinea tonsurans accounts for the vast majority of …

TENSE BULLAE ON AN ERYTHEMATOUS BASE

The patient is a 79 year old female who has multiple asymptomatic erythematous targetoid lesions on the chest, abdomen, and extremities, along with tense bullae. Nikolsky’s sign is negative. Diagnosis: Bullous pemphigoid, likely drug-induced. Histology: Sections in this biopsy of peribullous skin did not show a subepidermal split but did show an infiltrate of eosinophils, consistent with the so-called “prebullous phase” of bullous pemphigoid. Direct Immu…

WRINKLED YELLOW SKIN OF THE NECK

The patient is a 28 year old female who has developed an area of yellowed wrinkled skin on the lateral neck. Punch biopsy is performed. Elastic stain. Diagnosis: Pseudoxanthoma elasticum Discussion: Pseudoxanthoma elasticum is a rare genodermatosis with mutations in the ABCC6 gene. Women are affected twice as often as men. The cutaneous manifestations are usually the first to come to clinical attention and classically involve the lateral neck. . . . Histology shows …

A RAISED NODULE OF THE SCALP

The patient is a 68 year old man with a slowly enlarging nodule of the scalp. Excisional biopsy is performed. Diagnosis: Cutaneous lymphadenoma The cutaneous lymphadenoma is a rare benign neoplasm of uncertain histogenesis, although it is generally considered to be a variant of trichoblastoma. This lesion has also been reported under the names adamantinoid trichoblastoma and lymphoepithelial tumor of the skin. It typically occurs as a solitary non ulcerated and slowly enlargi…