Histiocytic sarcoma is a rare malignant neoplasm arising most commonly in lymph nodes, intestinal tract, skin and soft tissue. The incidence of primary CNS histiocytic sarcoma is even rarer with a total of just 27 cases reported in the literature so far. Herein we describe the first autopsy case of histiocytic sarcoma presenting as a diffuse leptomeningeal disease in absence of a CNS tumor-forming parenchymal lesion. The clinical, pathological and immunophenotypic features are described and an updated literature review on primary CNS histiocytic sarcoma is included.
Keywords: brain; central nervous system; histiocytic sarcoma; malignant histiocytosis; meninges.
© 2017 Japanese Society of Neuropathology.