A clinicopathological study of atypical teratoid/rhabdoid tumor with review of the literature

Background: Atypical teratoid/rhabdoid tumor (AT/RT) is a rare, aggressive neoplasm of the central nervous system occurring mainly in the early childhood. Objective: The objective of the present study was to study the clinicopathologic features of this newly recognized tumor. Materials and Methods: A retrospective search of pathology files from a series of brain tumors revealed five patients with features of AT/RT. The clinical, radiological and pathological features were analysed. Results: The cases included three boys and two girls with age ranging from 2 years to 15 years. The tumors were located in the infratentorial (three located in the cerebellar hemispheres) and supratentorial areas (two located in the parietal and frontal lobes). One of the cerebellar tumors involved bilateral cerebellopontine (CP) angles, mimicking a primary CP angle tumor (like neurofibroma) with two small deposits in the cerebrum (parietal lobe). Radiologically all the five cases had heterogeneous enhancement with two of them exhibiting cystic change within. Histopathologically, the tumors were composed of rhabdoid cells, undifferentiated small cells, mixed with epithelial, mesenchymal, and neural tumor-like areas. The proportion of each of these elements varied in all the four cases. One of the tumor had predominantly small cells with focal rhabdoid differentiation mimicking a medulloblastoma/primitive neuroectodermal tumor. Conclusion: AT/RT is an aggressive tumor with a varied clinical and pathological profile. The present case series helps in creating an awareness of this complex tumor and stresses the importance of correct diagnosis of this neoplasm that tends to have a bad prognosis.