Mycosis fungoides presenting as pigmented purpuric dermatitis.

Mycosis fungoides, a cutaneous T-cell lymphoma, typically presents as indolent, progressive, and persistent erythematous patches or plaques with mild scaling and over time can evolve into tumor stage with tumor nodules. Other presentations include eczematous, psoriasiform, poikilodermatous, and hypopigmented patches. We report Mycosis fungoides in a 14-year-old boy presenting as pigmented purpuric dermatitis and review the relevant literature.

Melanosis in association with metastatic malignant melanoma: report of a case and a unifying concept of pathogenesis.

An unusual case of melanosis associated with metastatic malignant melanoma is reported. This was characterized by progressive blue/gray discoloration of the skin of the chest and abdomen in an elderly patient, 1 year after removal of a polypoid malignant melanoma from the right arm. A biopsy of involved skin revealed perivascular aggregates of melanin-laden histiocytes throughout the dermis, the histopathologic hallmark of melanosis.

Eruptive xanthomata with urate-like crystals.

The microscopic manifestations of eruptive xanthomata are variable and although they are most frequently characterized by aggregations of foamy macrophages in the dermis, they can, on occasion, simulate granuloma annulare. We have recently encountered a further unusual histopathological variant of eruptive xanthomata in 3 skin biopsies from 2 patients with hypertriglyceridemia. The lesions had a granuloma annulare-like pattern at low magnification, the exceptional feature being their content of polarizable, needle-shaped crystals.