Squamoid eccrine ductal carcinoma: clinical, histological and immunohistochemical features.

Squamoid eccrine ductal carcinoma (SEDC) is a cutaneous adnexal malignancy that is histologically challenging to distinguish from squamous cell carcinoma. We report three cases of this rare entity and review the present literature regarding clinical, histological, and immunohistochemical features. Patients presented with a single nodule or plaque lesion on their back and temple.

Sarcoidosis with small syringotropic granulomas presenting clinically as a pigmented purpuric dermatosis: Inconspicuous clinical and histopathological clues to systemic illness.

Sarcoidosis is a multisystem granulomatous disease with a myriad of clinical manifestations and a predilection to involve the lungs, eyes, lymph nodes, and skin. A 38-year-old man presented to dermatology with a history of progressive dyspnea, pulmonary consolidations on chest X-ray, and hilar adenopathy on computed tomography scan. Skin exam revealed asymptomatic, yellow to brown macules on the right lower extremity.

Tumor-stage mycosis fungoides in palmoplantar localization with large-cell transformation and partial CD30 expression shows complete response to brentuximab vedotin.

Mycosis fungoides in palmoplantar localization (MFPP) is a rare variant of MF that is confined to the hands and feet. Patients commonly receive treatment over many years for suspected palmoplantar dermatitis before the diagnosis is made. Most MFPP patients remain at patch or plaque stage, and often respond to treatment with radiotherapy.

The many masks of cutaneous Lyme disease.

Early cutaneous Lyme disease, erythema migrans, may show different histopathologic patterns. The intent of this case series is to raise awareness of these findings to prevent misdiagnosis and keep this entity in the differential. Erythema migrans develops after a tick bite and subsequent infection with the spirochete, Borrelia burgdorferi.