Metastasis in central nervous system: Clinicopathological study with review of literature in a tertiary care center in South India

Background: Secondary central nervous system (CNS) tumors are common in Western countries, but in Indian literature, scant data are available. With the advent of newer imaging techniques, the confirmatory histopathological diagnosis has become comparatively easier. Hereby, we have analyzed our data from a single tertiary care center in south India. Materials and Methods: In this retrospective study from January 2000 to December 2010, histopathologically diagnosed secondary CNS tumors were reviewed along with clinical, imaging, and relevant immunohistochemical findings. Meningeal, lymphoproliferative, and myeloproliferative tumors and autopsy data were not included in the study group. Results: There were 40 secondary CNS tumors. Male to female ratio was 2.3:1. Age range was wide (28-75 years). Majority of cases were seen in the fourth and fifth decade. Imaging-wise, (computed tomography and magnetic resonance imaging) majority were single lesions ( n = 34, 85%). Most commonly, these single lesions were present in the cerebral hemisphere ( n = 20, 50%) followed by cerebellum ( n = 10, 25%). Adenocarcinoma accounted for maximum number of cases ( n = 25, 62.5%) with lungs being the most common primary. Conclusion: We have noted 25% metastatic adenocarcinomas in cerebellar location, which is higher when compared with available world literature. However, we also encountered a good number of cases (30%) due to unknown primary. Though histopathological examination with use of immunohistochemical markers can reliably distinguish primary from secondary CNS tumors in addition to available clinical and imaging data, particularly in developing countries, still a better work-up with an array of immunohistochemical markers and newer imaging modalities is desirable.