CYTOMORPHOLOGY OF FAMILIAL HEMOPHAGOCYTIC SYNDROME

Familial hemophagocytic syndrome (FHS) is a rare fatal disorder of chi ldhood demonstrating failure to thrive, fever, hepatosplenomegaly (HSM ), recurrent infections, pancytopenia, and histologically, the infiltr ation of reticuloendothelial organs by benign-appearing histiocytes de monstrating hemophagocytosis. We report two fatal cases of FHS includi ng a 3 year-old female who underwent fine-needle aspiration (FNA) biop sy of the liver in the initial workup of the disease (case 1) and an 8 month-old boy with ascites and HSM having peritoneal fluid cytology s ubmitted as the first specimen for morphologic examination (case 2). I n case 1, the FNA cytologic findings included benign hepatocytes and s cattered mature and reactive lymphocytes and histiocytes. The histiocy tes demonstrated fine to coarse cytoplasmic vacuoles and erythrophagoc ytosis. The diagnosis was confirmed at autopsy which revealed extensiv e lymphohistiocytic infiltrates in various organs including the centra l nervous system. In case 2, the peritoneal fluid cytology specimen co ntained numerous atypical and degenerating mononuclear lymphoreticular cells which were dispersed as a single cell suspension admixed with i nfrequent mesothelial elements; hemophagocytosis was not appreciated S ubsequent liver biopsy revealed portal tracts and sinusoids infiltrate d by benign but atypical histiocytes with hemophagocytosis. Bone marro w examination and then autopsy confirmed the diagnosis of FHS. A panel of immunocytochemical studies was performed in the first case which w as an aid in confirming the diagnosis of FHS and ultrastructural exami nation of the second case revealed well-developed erythrophagocytosis. Both patients had siblings who died of FHS. Although not diagnostic, cytomorphology may suggest FHS. (C) 1993 Wiley-Liss, Inc.