Triple-negative breast cancer (TNBC) is an uncommon but important high-risk phenotype, which often has unusual morphological or cytological features. In this poster, we describe a case of metastatic triple-negative breast cancer detected in the cerebrospinal fluid (CSF) of a 49-year-old patient using conventional cytology stains, and a cell block with immunohistochemistry and molecular techniques.
Pepperell et al. (Sun,) studied this question.