Hepatic involvement in hairy cell leukemia.

Nineteen patients with hairy cell leukemia were studied in order to define the hepatic changes in this disease and to correlate the morphologic changes in the liver with the clinical and biochemical findings. Although only eight of the patients had hepatomegaly, all 19 had microscopic mononuclear cell infiltration in the sinusoids or the portal areas or both. The severity of mononuclear infiltration in the liver correlated poorly with the size of the liver or spleen, the biochemical changes, or number of hairy cells in the blood. Abnormal serum biochemical values were present occasionally and were usually due to associated diseases or to complications of this disease. Elevated serum alkaline phosphatase activity was noted in four patients; three of them had granulomatous lesions in the liver. Unless the characteristic "clear cell" pattern is seen, the hepatic mononuclear cell infiltration may not be diagnostic of hairy cell leukemia and, in many instances, may not even be suggestive of neoplasia. A new technique for demonstrating tartrate-resistant acid phosphatase activity in methacrylate-embedded sections was developed, which allowed identification of hairy cells in the liver biopsy specimens of all five patients so studied. The authors concluded that liver involvement is common in this disease.