Central nervous system tumors: Radiologic pathologic correlation and diagnostic approach

OBJECTIVE: This study was conducted to formulate location-wise radiologic diagnostic algorithms and assess their concordance with the final histopathological diagnosis so as to evaluate their utility in a rural setting where only basic facilities are available. MATERIALS AND METHODS: A retrospective analysis to assess the concordance of radiology (primarily MRI) with final histopathology report was done. Based on the most common incidence of tumor location and basic radiology findings, diagnostic algorithms were prepared. RESULTS: For supratentorial intraaxial parenchymal location concordance was seen in all high-grade astrocytomas, low- and high-grade oligodendrogliomas, metastatic tumors, primitive neuroectodermal tumors, high-grade ependymomas, neuronal and mixed neuro-glial tumors and tumors of hematopoietic system. Lowest concordance was seen in low-grade astrocytomas. In the supratentorial intraaxial ventricular location, agreement was observed in choroid plexus tumors, ependymomas, low-grade astrocytomas and meningiomas; in the supratentorial extraaxial location, except for the lack of concordance in the only case of metastatic tumor, concordance was observed in meningeal tumors, tumors of the sellar region, tumors of cranial and paraspinal nerves; the infratentorial intraaxial parenchymal location showed agreement in low- as well as high-grade astrocytomas, metastatic tumors, high-grade ependymoma, embryonal tumors and hematopoietic tumors; in the infratentorial intraaxial ventricular location, except for the lack of concordance in one case of low-grade astrocytoma and two cases of medulloblastomas, agreement was observed in low- and high-grade ependymoma; infratentorial extraaxial tumors showed complete agreement in all tumors of cranial and paraspinal nerves, meningiomas, and hematopoietic tumors. CONCLUSION: A location-based approach to central nervous system (CNS) tumors is helpful in establishing an appropriate differential diagnosis.