Leptomeningeal metastases: comparison of clinical features and laboratory data of solid tumors, lymphomas and leukemias.

We reviewed 63 cases of cytologically confirmed leptomeningeal metastases (LM). 31 (49%) had solid tumors 17 (27%) had leukemia and 15 (24%) had lymphoma. The most common presenting symptom was pain (76%) with radicular discomfort (58%), headache (32%), neck or back pain (17%). The predominant neurological signs were mental status abnormalities (49%), weakness (47%), seizures (14%). The mode of presentation varied with tumor type. Patients with leukemia (18%) and lymphoma (13%) tended to present frequently with LM without systemic involvement, or during periods of apparent remission (leukemia 35%, lymphoma 27%), while patients with solid tumors had established systemic metastases (90%) at time of presentation. Laboratory studies did not vary among the groups. 71% had positive cytology on the first lumbar puncture (LP) and only 8% required more than 2 LPs. The cell count was a poor predictor of positive cytology as 29% of LP's with positive cytology and 36% of all LP's had less than 4 cells/mm. We conclude that 1) LM presents with pain and seizures more frequently than has been previously recognized; 2) LM is frequently the mode of presentation in patients with leukemia and lymphoma and; 3) cytology is positive frequently in CSF specimens with normal cell counts and chemistries.