Null-Cell Ectopic Pituitary Adenoma of the Nasal Cavity

Abstract

An ectopic pituitary adenoma (EPA) is an uncommon type of pituitary adenoma, accounting for only 2% of all pituitary adenomas. EPAs are benign tumors that can occur anywhere along the migratory embryonic path of the pituitary gland and have no relationship to intrasellar elements. They are usually hormonally active and have a minor female predominance. The clinical features of EPAs are highly dependent on its hormonal activity, anatomical location, and its local mass effect. Appropriate radiological imaging is essential for the evaluation of EPAs. Imaging investigations show a normal pituitary gland and sellar turcica, provide details on the size of the tumor, its margins, and extent, and help with surgical planning. The criteria for diagnosing an ectopic pituitary adenoma depend on detailed histopathological examination. EPA management should be individualized. We present a case of a 71-year-old male who presented with a 9-month history of left nasal obstruction, purulent nasal discharge, and intermittent anterior epistaxis. The patient was being managed by his general practitioner for chronic rhinosinusitis but failure of his symptoms to resolve prompted a visit to the otorhinolaryngologist. The patient was diagnosed with a null-cell ectopic pituitary adenoma through histological analysis of a biopsy specimen that showed adenohypophyseal cells without cell-type-specific differentiation. The patient subsequently underwent an endoscopic endonasal excision and had an uneventful hospital stay.