Systemic mastocytosis, myelofibrosis and portal hypertension.

A case of systemic mastocytosis is described in which the finding on initial presentation was hepatosplenomegaly. No dermatological abnormality was present, and the bone marrow histology originally caused some confusion with primary myelofibrosis. The clinical course and the importance of distinguishing between these two diseases is discussed. The dermatological manifestation of systemic mastocytosis, in the form of urticaria pigmentosa, is well recognised, and alerts the physician to the underlying disease. In the absence of cutaneous signs, however, the diagnosis is less obvious. The case reported had predominantly marrow and splenic involvement by the disease process, giving rise to portal hypertension, and illustrates the problems of diagnosis which can arise.