Abstract
BACKGROUND: Primary pituitary abscess is a rare disease with no specific symptoms for pituitary abscess alone. A preoperative diagnosis is quite challenging due to unclear imaging findings. CASE PRESENTATION: We report the case of a patient with a pituitary lesion who presented with hypopituitarism, diabetes insipidus, and visual field defect and was misdiagnosed as a possible cystic pituitary adenoma. Endoscopic endonasal transsphenoidal surgery (ETSS) was performed, and surprisingly, only pus was found, and complete resection of the lesion was achieved. Coagulase-negative staphylococci were detected in the culture, and appropriate antibiotic therapy was administered for six weeks. Diabetes insipidus and hypopituitarism did not improve. One year later, the abscess recurred, and a second operation with complete resection was performed. CONCLUSION: Knowledge of primary pituitary abscess, a rare infectious disease, is essential for early detection and successful treatment. Most patients have a chronic and silent prediagnostic course with symptoms that are not specific to pituitary abscess alone. The primary treatment option is EETS, followed by long-term, relevant antibiotics. The disease can be resistant and recur despite appropriate treatment, especially in patients with risk factors. Therefore, long-term follow-up of patients is essential.