Subcutaneous T-cell lymphoma: a case report and additional observations.

Subcutaneous T-cell lymphoma is rare. Differentiation from several clinically similar entities such as malignant histiocytosis, histiocytic cytophagic paniculitis, Weber-Christian disease, and systemic lymphoma can be difficult. Our patient presented with plaquelike lesions on her lower extremities, fevers, hepatic dysfunction, and a laboratory-proven coagulopathy. Examination of a skin biopsy specimen revealed a benign-appearing histiolymphocytic infiltrate with panniculitis and erythrophagocytosis. Immuno-histochemical staining of the infiltrate demonstrated a predominance of T cells. At autopsy, an atypical T-cell infiltrate was noted in the skin, subcutis, and other organs. Subcutaneous T-cell lymphoma is a rare type of peripheral T-cell lymphoma whose diagnosis is problematic. Based on the initial difficulty finding the lymphomatous infiltrate in our case, it is conceivable that previously reported cases of histiocytic cytophagic panniculitis, malignant histiocytosis, and Weber-Christian disease were in fact unrecognized cases of lymphoma.