Pituitary atypical teratoid rhabdoid tumor in a patient with prolactinoma: A unique description.

Atypical teratoid rhabdoid tumor (ATRT) is an aggressive tumor of the CNS and characteristically occurs in the pediatric age. In adulthood, ATRT is rare and it is mainly localized in the cerebral hemispheres. Only 16 cases of ATRT have been described in the sellar region up to now. Interestingly, all sellar ATRTs occurred in adult female patients. Herein we report a novel case of sellar ATRT in a patient with previous history of lactotroph adenoma. Similar to other sellar ATRTs, this case occurred in a female adult patient. At histological examination, it was characterized by a small number of rhabdoid cells. In addition, it did not have homozygous deletion of SMARCB1 gene, but it rather showed a frameshift mutation at exon 4 of SMARCB1 which had not been previously found in ATRT. Clinico-pathological and molecular findings observed in this case confirm previous evidence that sellar ATRT seems to be a distinct entity. Association with previous prolactin-secreting pituitary adenoma is discussed.
(© 2017 Japanese Society of Neuropathology.)