Incidentally Found Pituitary Macroadenoma Presenting as Primary Tumor Arising from Sphenoid Sinus during F-18 FDG PET/CT Imaging

摘要

Most pituitary incidentalomas are adenomas. They are classified as microadenoma (< 10 mm), macroadenoma (> 10 mm) and giant pituitary adenoma (> 40 mm). Invasive pituitary adenoma means the surrounding structures are invaded. We present an incidentally found hypermetabolic lesion at sphenoid sinus with the upper portion extending into pituitary fossa during F-18 FDG PET/CT imaging in an asymptomatic 70 year-old female with history of uterine endometrioid adenocarcinoma. MRI revealed the tumor epicenter at sphenoid sinus and normal pituitary gland was displaced laterally. The differential diagnosis included ectopic sphenoid sinus pituitary adenoma (with normal anterior pituitary gland), pituitary adenoma with atypical manifestation, primary tumor arising from sphenoid sinus (e.g., neuroendocrine tumor), chordoma, and metastasis, etc. Pathology revealed pituitary adenoma after Trans-sphenoidal resection.