Mixed Gangliocytoma-Pituitary Adenoma: Incidental Discovery During Eye Injury Evaluation: A Case Study

Abstract Introduction/Objective Mixed gangliocytoma-adenoma is exceedingly rare, representing less than 0.5% of sellar tumors. We present a unique case of mixed gangliocytoma-pituitary adenoma incidentally diagnosed during the evaluation of traumatic eye injury. We aim to clarify the diagnostic process using real clinical data, stressing how such cases might be missed without careful histopathological examination Methods/Case Report A 32-year-old male presented for elective transsphenoidal resection (TSR) due to a suspected growth hormone (GH) secreting pituitary tumor. Surprisingly, the adenoma was discovered incidentally during an eye injury evaluation. Referred from an ophthalmology clinic, initial concerns were a possible blood clot or foreign body in the left eye, following a forceful encounter with a tree branch Results (if a Case Study enter NA) Imaging incidentally identified a 2 cm pituitary mass. Further evaluation showed elevated levels of insulin-like growth factor 1 (IGF1) at 1162 ng/ml and GH at 10.2 ng/ml. Remarkably, the patient had not observed signs of acromegaly, until photographic comparison between past and present appearances was made. TSR of the pituitary mass was done. Microscopic examination revealed monomorphic cells with round nuclei with the typical speckled chromatin pattern of neuroendocrine cells with cytoplasm ranging from chromophobic to eosinophilic, consistent with pituitary adenoma. An additional unexpected finding was the presence of large gangliocytic cells (large neurons), dispersed throughout the tumor as single or clustered cells. In some regions, distinct patches of fine neuropil stroma were associated with the clustered ganglion cells. IHC staining with synaptophysin and neurofilament highlighted the gangliocytic component. CAM 5.2 IHC stain showed perinuclear dot-like expression in the adenoma cells, GH IHC showed patchy expression, and prolactin IHC was expressed in scattered cells. Ki67 index was ~ 2%. There was no evidence of necrosis nor mitosis. The coexistence of sellar gangliocytoma with pituitary adenoma, as observed in this case, represents a rare entity known as mixed gangliocytoma-pituitary adenoma Conclusion The adenomatous component of mixed gangliocytoma-pituitary adenoma often secrete GH, leading to its classification as pituitary somatotroph adenoma. This poses a diagnostic challenge due to the lack of specific symptoms or unique brain imaging features, necessitating thorough histological evaluation for precise diagnosis and to ensure the gangliocytoma component is not overlooked