Pituitary Abscess Arising in Prolactinoma Difficulties in Differentiating Between Intratumoral Pituitary Abscess and Pituitary Apoplexy

摘要

A case with a presumable abscess in a pituitary tumor is presented. A 20-year-old woman was evaluated for secondary am-enorrhea, A mass in the left half of the pituitary gland was found with magnetic resonance imaging (MRI). An elevated serum pro-lactin (PRL) led to an initial diagnosis of pituitary prolactinoma. The administration of oral bromocriptine (2.5 mg per day) led to regular menstrual periods. Two years later, she returned with reappearance of amenorrhea. MRI on admission revealed expansion of the intra-sellar mass, which had an unusual hyperintense area in the center on Tl-weighted image. The preoperative diagnosis was intratumoral hemorrhage, ie, pituitary apoplexy. Transsphenoidal surgery was performed. Purulent material was found on opening the dura. His-topathologic findings showed polymorphic neutrophil infiltration accompanied by clusters of degenerated prolactinoma cells. The bacterial culture, fungal culture, and polymerase chain reaction for mycobacterium were negative. She had a medical history of tooth extraction and oral antibiotics several years previously, but there was no evidence of current or previous septicemic illness, meningitis, cavernous sinus thrombosis, or sinus infection. She was given antibiotics for 2 weeks and discharged. Recurrence and hormonal deficits have not been observed since surgery 2 years ago. Intratumoral pituitary abscess accounts for one third of pituitary abscesses. The condition is well known for its diagnostic complexity, both radiologically and histopathologically. The genesis and development of sterile pituitary abscess may correlate with the increasing use of antibiotics in recent years. However, the etiology of intratumoral pituitary abscess remains unclear and controversial.