Secondary Pituitary Abscess Inside a Macroadenoma Complicated by Postoperative Hemorrhage and Reinfection: A Case Report

BACKGROUND Pituitary abscess is a rare, potentially life-threatening condition that is challenging to diagnose on magnetic resonance imaging (MRI). Here, we present a case of pituitary abscess within an adenoma with a complicated postoperative course. CASE REPORT A 72-year-old man with progressive headache and left-eye visual field deficit underwent MRI, which revealed a parasellar region lesion compressing the optic chiasm, suggesting a pituitary macroadenoma. An endoscopic transnasal transsphenoidal approach was used for total tumor resection, during which purulent material was evacuated. Pathology confirmed a pituitary adenoma, and microbiology identified Proteus mirabilis and Cutibacterium acnes. Postoperatively, the patient's vision did not improve due to a hemorrhage in the postoperative bed necessitating reoperation. Staphylococcus epidermidis was isolated from the second procedure. Following hematoma evacuation, his vision improved. CONCLUSIONS Pituitary abscess within an adenoma is rare and difficult to diagnose with MRI. Symptoms overlap with those of pituitary adenomas and abscesses, making clinical recognition challenging. Management requires prompt abscess drainage, lesion resection, and prolonged antibiotic therapy. This case demonstrates the importance of maintaining a broad differential diagnosis and not focusing on a single suspected pathology.