An incomplete picture: challenges of partial biopsies in large diameter atypical melanocytic lesions.

Large diameter atypical pigmented lesions (LDAPL) can be challenging to diagnose accurately using partial biopsies because of pathologic heterogeneity, while at the same time large excisions of these lesions confer significant morbidity to patients. Consequently, clinicians are often challenged by the management of these lesions. In this case, we describe an elderly patient with a history of multiple basal cell carcinomas, prior melanomas, and a family history of melanoma who presented with an irregularly pigmented brown and dark brown patch on his upper back.

Chemical burn caused by topical application of garlic under occlusion.

Allium sativum (garlic) can cause an irritant contact dermatitis, secondary to naturopathic practices. We report an unusually severe case of chemical burn following garlic applied under occlusion.

Lymphangioma circumscriptum.

A 54-year-old man presented for evaluation of multiple 1- to-4-mm, clear, pink, red, and black vesicles overlying hyperpigmented and erythematous indurated plaques on his right thigh and extending to his right inguinal fold. Clinical presentation and histopathologic features were consistent with lymphangioma circumscription. Lymphangioma circumscriptum is the most common cutaneous form of lymphangioma.

Sarcoidosis with subcutaneous lesions.

A 30-year-old man presented for evaluation of multiple, hypopigmented macules and erythematous papules on his upper and lower lips and upper extremities. He subsequently developed firm, non-tender, subcutaneous, mobile nodules on the left forearm, left calf, and right thigh. Clinical and histopathologic features were consistent with cutaneous and subcutaneous sarcoidosis.

Eruptive vellus hair cysts.

A 20-year-old man presented with multiple, asymptomatic, follicular papules that were distributed over his abdomen. Microscopic examination showed classic features of a vellus hair cyst. The term eruptive vellus hair cysts refers to a benign condition, which may be inherited or acquired.

Acroangiodermatitis.

A 26-year-old man with a history of chronic primary lymphedema of the left lower extremity presented with elephantiasis, confluent, violaceous, mascerated plaques, and ulcers on the dorsal aspects of the toes of the left foot. Histopathologic examination showed a proliferation of small blood vessels associated with extravasated erythrocytes and hemosiderin deposits consistent with the diagnosis of acroangiodermatitis. Treatment of the focal ulcers includes compression therapy, local wound care, and surgical elimination of the shunt if there is an associated arteriovenous malformation.

Behçet disease (incomplete) and cutaneous polyarteritis nosa.

A 42-year-old man with a 2-year history of left posterior uveitis and recurrent oral aphthous ulcers presented for evaluation of recurrent, erythematous, subcutaneous, tender nodules on his lower extremities. A biopsy specimen of the nodules showed a medium-sized-vessel vasculitis with a mild and moderate inflammatory cell infiltrate in the septae and lobules of the subcutaneous adipose tissue. These changes were consistent with cutaneous polyarteritis nodosa.

Diffuse Bier spots.

A 34-year-old man presented with a 6-month history of hypopigmented macules that were interspersed with blanching erythematous macules on the trunk, upper extremities, and lower extremities. Bier spots are small, hypopigmented macules that are usually found on the arms and legs of young adults. The intervening skin may seem erythematous but blanches with pressure so that the hypopigmented macules disappear.