Primary Central Nervous System Histiocytic Sarcoma with Skull Base and Ventricular Dissemination: A Case Report and Literature Review

Purpose The primary objective of this case report is to highlight the clinical challenges and diagnostic difficulties of histiocytic sarcoma (HS) involving the central nervous system (CNS). This case emphasizes the importance of accurate diagnosis in patients presenting with nonspecific neurological symptoms, particularly when the disease is rare and aggressive. Methods We present the case of an 18-year-old female with a 9-month history of progressive headaches and seizures. Initial misdiagnosis as viral meningitis was corrected through MRI and cerebrospinal fluid (CSF) analysis. The definitive diagnosis of CNS-HS was confirmed through a neuroendoscopic biopsy via the lateral ventricle. Results MRI revealed a lesion in the right medial temporal lobe with extensive skull base infiltration and intraventricular dissemination. CSF analysis showed hypoglycorrhachia and elevated protein levels without pleocytosis. A neuroendoscopic biopsy from the lateral ventricle confirmed the diagnosis, with tumor cells showing strong immunoreactivity for CD68 and CD163. Conclusion This case highlights the diagnostic challenge of CNS-HS, emphasizing the need for advanced neuroimaging, CSF metabolic analysis, and early biopsy for accurate diagnosis. Given the rapid progression and poor prognosis, early detection and molecular profiling could offer potential avenues for targeted therapeutic strategies.