Diagnostic yield of postmortem brain examination following premortem brain biopsy for neoplastic and nonneoplastic disease

Medical autopsies have decreased in frequency due in part to advances in radiological techniques and increased availability of molecular and other ancillary testing. However, premortem diagnosis of CNS disease remains challenging; while similar to 90% of brain tumor biopsies are diagnostic, only 20%-70% of biopsies for presumed nonneoplastic disease result in a specific diagnosis. The added benefits of performing an autopsy following surgical brain biopsy are not well defined. A retrospective analysis was performed of patients who underwent brain biopsy and autopsy at Brigham and Women's Hospital from 2003 to 2022. A total of 135 cases were identified, including 95 (70%) patients with primary CNS neoplasms, 16 (12%) with metastatic tumors, and 24 (18%) with nonneoplastic neurological disease. Diagnostic concordance between biopsy and autopsy diagnosis was excellent both for primary CNS neoplasms (98%) and metastatic tumors (94%). Conversely, patients with nonneoplastic disease received definitive premortem diagnoses in 7/24 (29%) cases. Five (21%) additional patients received conclusive diagnoses following autopsy; 8 (33%) received a more specific differential diagnosis compared to the biopsy. Overall, autopsy confirmed premortem diagnoses or provided new diagnostic information in 131/135 (97%) cases, highlighting the value in performing postmortem brain examination in patients with both neoplastic and nonneoplastic diseases.