lmportance of Repeated Lumbar Punctures in Leptomeningeal Carcinomatosis

Abstract

Scientific Background: Traditionally, to establish a definitive diagnosis of leptomeningeal carcinomatosis (LMC) requires the demonstration of malignant cells in cerebrospinal fluid (CSF). Fifty percent of cases are found positive for malignancy with the first CSF specimen, whereas up to 90% are found positive after subsequent lumbar punctures.Objective: To assesses value of repeating lumbar punctures (LP) in patients with LMCMaterial and Methods: This is a prospective study. Nine patients who were diagnosed as LMC according to their clinical features, MR imaging findings and the CSF cytological results were included in the study. LP was repeated 3 times as maximal, and it was accepted as negative if there were no malignant cells in the CSF cytological examination after the 3rd LP. Results: Malignant cells were seen in 5 of the 9 patients in the first CSF cytological examination, and the number increased to 7 and 8 of the 9 patients at 2nd and 3rd LPs respectively. Remaining 1 patient was diagnosed to LM C according to the clinical features plus MR findings. MR imaging was positive in 4 of the 9 patients. Primary sites of 8 of the 9 patients were hematological malignancies, and last one was small cell cancer of the lung. Conclusion: In order to make a definitive diagnosis of LMC multipleLPs are important especially in hematological malignancies.