Patient with AIP gene mutation presenting with pituitary adenomatosis

Abstract

Abstract Introduction/Objective Familial isolated pituitary adenoma (FIAP) is frequently associated with germline mutation in the AIP gene. Clinically, it is characterized by the occurrence of isolated pituitary adenoma in 2 or more members of a family. In this case report, we describe a patient who presented with a pituitary adenoma and concurrent disseminated leptomeningeal adenomatosis. Methods/Case Report A 17-year-old female presented with amenorrhea and visual impairment. Brain MRI showed a 2.6 x 2.8 x 2.4 cm mass in the sella turcica extending to the suprasellar region. Multiple separate smaller (5-7 mm) masses in the leptomeninges of the anterior and middle cranial fossa, and small enhancing masses within the internal auditory canals bilaterally were also seen. She underwent craniotomy for resection of the pituitary tumor which was diagnosed pathologically as sparsely granulated somatotroph adenoma with co-expression of human growth hormone and prolactin. Postoperatively, she was found to have persistent hormone imbalance for which she received proton beam therapy. Genetic testing revealed mutations in the AIP gene. No mutations were detected in NF2, MEN1, and CDKN1B. At age 21, radiologic follow-up revealed recurrent pituitary adenoma, for which she underwent trans- sphenoidal resection, revealing the same histopathologic diagnosis. At age 22, MRI showed diffuse nodular enhancement throughout the subarachnoid spaces, most pronounced within the Sylvian fissures. Cytologic examination of cerebrospinal fluid (CSF) showed several loose aggregates of neuroendocrine cells, positive for synaptophysin by immunocytochemistry, consistent with the diagnosis with dissemination of pituitary adenoma cells in the leptomeninges. Results (if a Case Study enter NA) N/A Conclusion In all 136 previously reported cases, leptomeningeal dissemination of pituitary adenoma has been exclusively described in post-surgical settings or after pituitary apoplexy. To our knowledge, this is the first case of disseminated pituitary adenomatosis noted at initial clinical presentation