The utility of repeated cytologic evaluation of cerebrospinal fluid in individuals with metastatic breast cancer

IntroductionMetastasis of breast cancer to the central nervous system, either in the brain parenchyma or leptomeninges (LMC), is a late feature of the disease .Detection of malignant cells in the cerebrospinal fluid (CSF) is the diagnostic standard for LMC. Repeated CSF examinations are often performed following an initial diagnosis positive for malignancy. This study evaluates the significance of repeated CSF evaluation in women with metastatic breast cancer to the central nervous system.Materials and MethodsCases of adenocarcinoma of breast diagnosed by CSF cytology from 1990 through 2012 documenting: age, radiologic findings, treatment modality, and the number of repeated CSF cytology specimens and their respective interpretations.ResultsFifty-one patients were identified; 28 patients (54.9%) had a single initial positive CSF performed and 23 (45.1%) had multiple CSF cytology samples (range = 2-25, mean = 5.5). Despite interval “negative” and “atypical cells” results on CSF cytology specimens, all 23 patients with multiple samples had at least one follow-up positive CSF cytology sample.ConclusionThe prognosis of the patients with an initial CSF diagnosis of adenocarcinoma was poor, regardless of the respective interpretations on the repeated CSF specimens, even in the presence of interval negative CSF.