Cytopathological differential diagnosis of malignant tumor cells in the cerebrospinal fluid: A retrospective analysis.

Leptomeningeal metastasis is the spread of cancer to the leptomeninges and subarachnoid space and represents a dreadful complication of cancer. The most commonly responsible neoplasms are high-grade lymphomas, leukemias, and some solid tumors, chiefly breast and lung cancer as well as melanoma. Herein we report our ten-year retrospective experience on 715 cases of cerebrospinal fluid cytology, 21 (2.9%) of which were positive for leptomeningeal metastasis. Sample collection and processing, clinical history, interdisciplinary dialog, and ancillary techniques such as immunocytochemistry and flow cytometry are all fundamental in reaching the correct diagnosis and thus optimally caring for patients with leptomeningeal metastasis.