Foreign body granuloma mimicking pituitary adenoma: Case report and literature review

Background: Foreign body granuloma of the pituitary gland is an exceptionally rare inflammatory lesion that may mimic recurrent adenoma on neuroimaging. Case Description: We report the case of a 44-year-old woman who previously underwent endonasal endoscopic surgery for a nonfunctioning pituitary adenoma and later developed a sellar mass secondary to a foreign body granulomatous reaction. Magnetic resonance imaging suggested tumor recurrence; however, gadolinium-enhanced imaging was not performed because of the patient’s known gadolinium allergy. Histopathological examination revealed xanthogranulomatous inflammation and a multinucleated giant-cell reaction to the suture material, without evidence of neoplastic recurrence. Conclusion: This case highlights the diagnostic challenges associated with postoperative sellar lesions and emphasizes the importance of histopathological confirmation in distinguishing foreign body granulomas from recurrent pituitary adenomas.