RF13 | PMON83 Culture Negative Pituitary Abscesses: A Case Series
Authors: Pechman Amanda , Mathew Justin , Epstein Eric , Lee Hanna 
Published: November 2022

Abstract

Introduction
Pituitary abscesses are rare, representing less than 1% of pituitary lesions. Patients may present with pituitary hypofunction, headache, and/or vision changes, often without systemic or biochemical signs of infection, with diagnosis only made intraoperatively.

Cases
A 74-year-old man with history of diabetes and coronary artery disease presented with headache and left-eye ptosis. MRI revealed a 1.8 cm hypoenhancing cystic, hemorrhagic sellar mass extending into the left cavernous sinus. Pre-operative labs showed AM cortisol 1.1 ug/dL, testosterone 43 ng/dL (reference range 250-1100), FSH 15.3 mIU/mL, LH 4.5 mIU/mL consistent with adrenal insufficiency and hypogonadism. He underwent transsphenoidal pituitary resection (TSR) during which frank pus was demonstrated after incision into the dura overlying the pituitary. Surgical pathology showed necrosis and granulation-type reaction with acute inflammatory cell infiltrates. Gram stain and methenamine silver stains did not reveal definite micro-organisms while tissue bacterial cultures showed normal skin flora. He remained hemodynamically stable without fevers throughout the hospitalization and was discharged on empiric antibiotics and hydrocortisone.
A 74-year-old female with history of a pituitary macroadenoma was admitted for worsening headaches. Labs were consistent with her known history of secondary adrenal insufficiency and hypogonadotropic hypogonadism. Repeat MRI showed characteristics suggestive of hemorrhage within a 1.8 cm intrasellar mass with inhomogeneous and peripheral enhancement after contrast. She underwent TSR and intraoperatively frank pus was encountered. Surgical pathology showed sinonasal mucosa with chronic inflammation. There was no growth in aerobic, fungal, or AFB cultures; anaerobic cultures grew rare commensal bacteria. She was discharged with a course of antibiotics and remains on hydrocortisone.
A 42-year-old male presented with headache and was found to have a 2.5 cm sellar mass with rim enhancement elevating and compressing the optic chiasm on MRI. Labs were significant for AM cortisol 4.9 ug/dL and testosterone 8 ng/dL, FSH 0.4 mIU/mL, LH &lt;0.2 mIU/mL consistent with adrenal insufficiency and hypogonadism. He underwent TSR and was found to have purulent debris in the sella. Pathology showed epithelial tissue fragments insufficient for diagnosis, and cultures grew few skin and oropharyngeal contaminants. He was discharged on hydrocortisone with a course of antibiotics.

Conclusion
We describe three patient cases presenting with headache and varying degrees of hypopituitarism, found to have purulent material emanating from the sella during transsphenoidal resection. None presented with clinical or biochemical systemic signs of infection. MRI imaging was variable, ranging from cystic, hemorrhagic features to peripheral enhancement. Surgical pathology and cultures were unrevealing for a definitive infectious source or other cystic lesion such as Rathke's cleft cyst. This case series demonstrates the potential nonspecific presentation of pituitary abscesses including negative cultures and pathology. It is important to keep this rare diagnosis in the differential for patients presenting with pituitary disease.
Presentation: Sunday, June 12, 2022 12:30 p.m. - 12:35 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.