Malignant lymphoma of the skin: a clinicopathologic study of lymphoma other than mycosis fungoides.

The clinical and histopathologic findings in 25 cases of malignant lymphoma of the skin other than mycosis fungoides were reviewed. All patients had skin lesions as a primary manifestation of the disorder, and none had histopathologic evidence of extracutaneous involvement at the time of skin biopsy. The majority of patients had solitary nodules involving the skin of the head and neck region. Twenty-two of the skin biopsy specimens were interpreted as lymphocytic lymphoma, well or poorly differentiated, nodular or diffuse. Only three cases of histiocytic lymphoma (reticulum cell sarcoma) were encountered, and there were no cases of Hodgkin's disease of the skin. Twenty-two patients (88%) subsequently developed extracutaneous lymphoma: the interval from the occurrence of apparently localized skin lesions to involvement of lymph nodes and/or viscera ranged from 6 months of 5 years (mean duration of 21 months). Sixteen patients (64%) died of disseminated lymphoma, with survivals that ranged from 8 months to 12 years (mean survival of 3.7 years). Only three patients survived without disease for greater than 1 year. There was no definite relationship between either the histologic subtype of the tumor or the mode of therapy and prognosis. The patholoic findings indicate that a definite diagnosis of malignant lymphoma can be made by skin biopsy in patients with disease apparently confimed to the skin. Careful, detailed examination of the skin biopsy specimen provides a basis for distinguishing malignant lymphoma from cutaneous lymphoid hyperplasia. The clinical findings and survival data support the conclusion that malignant lymphoma with skin lesions as a primary manifestation almost invariably disseminates to extracutaneous organs and usually has a fatal outcome.