Malignant histiocytosis X. Report of a rapidly fatal case in an elderly man.

A 71-year-old white man developed an increasing number of 1-to-10 mm, erythematous nodules, many with central ulceration, most prominent on the head and trunk. Biopsy of a nodule showed infiltration of the dermis and epidermis by large cells with multilobulated nuclei and numerous mitoses. Electron microscopy showed that most tumor cells contained Langerhans' cell granules. Immunohistochemical studies demonstrated a pattern of antigen expression similar to that of Langerhans' cells including Ia and Leu-6 (T6) antigens. Chest x-ray showed diffuse pulmonary infiltration and similar tumor cells were present in the sputum and urine. He developed increasing dyspnea and jaundice despite chemotherapy, and died 6 months after the onset of the disease. Autopsy showed massive tumor infiltration of the lungs, liver, spleen, and lymph nodes, and focal involvement of the myocardium, skin and bladder. Clinical and cytologic features indicated this case to be a rare example of highly malignant histiocytosis X in an elderly man.