Atypical pituitary abscess lacking rim enhancement and diffusion restriction with an unusual organism, Moraxella catarrhalis: A case report and review of the literature

Background: Pituitary abscess (PA) can be fatal if diagnosed late. Rim enhancement is a typical radiological finding of PA on postgadolinium T1-weighted magnetic resonance imaging (MRI). Diffusion-weighted imaging is helpful in distinguishing PA from other sellar cystic lesions. Herein, we report the first atypical case of PA showing neither rim enhancement nor diffusion restriction with an unusual organism, Moraxella catarrhalis. Case Description: A 77-year-old woman presented with headache, polyuria, polydipsia, and fatigue for a month before presenting to a local hospital. MRI showed pituitary enlargement with contrast enhancement. She had neither fever nor visual deficits and was followed up with hormonal replacement. Six months later, she complained of visual impairment, and MRI showed further pituitary enlargement with a thickened stalk compressing the optic chiasma. Neither rim enhancement nor diffusion restriction was observed. Endoscopic endonasal transsphenoidal surgery was performed based on the radiological diagnosis of lymphocytic hypophysitis or pituitary tumors. A thick, creamy yellow pus was drained from the sellar lesion. Intraoperative rapid histopathological findings revealed polymorphonuclear leukocytes infiltrating the pituitary gland. PA was diagnosed, and irrigation and open drainage of the abscess was performed. Bacterial culture of the pus detected M. catarrhalis by mass spectrometer, confirming the diagnosis. She underwent appropriate antibiotic administration, and her visual deficits improved. Conclusion: We report the first atypical case of PA showing neither rim enhancement nor diffusion restriction with M. catarrhalis. Even if preoperative findings are not suggestive of PA, it should be considered as a differential diagnosis. Intraoperative rapid histopathological findings are useful for accurately diagnosing PA and initiating appropriate surgical treatment.

Case of an atypical pituitary abscess

A pituitary abscess is a rare intrasellar infection. Correct identification can be challenging preoperatively given its non-specific symptoms and imaging findings. We report a case of a young woman presenting with secondary amenorrhea, visual field deficits and a 2.6 cm pituitary lesion diagnosed to be a craniopharyngioma. A concomitant unexpected pituitary abscess was diagnosed intraoperatively without associated meningeal symptoms.

1351 Primary Pituitary Abscess Presenting as An Isolated Bitemporal Hemianopia

Pituitary abscesses are rare yet life-threatening entities. Most common presenting features are headache, hypopituitarism, and visual changes. Majority of patients are found to have a predisposing risk factor, such as a pre-existing pituitary lesion, recent pituitary surgery or irradiation, or a primary source of infection. We present the case of a 53-year-old male with a spontaneous pituitary abscess, who presented with an isolated bitemporal hemianopia, but was otherwise asymptomatic with no known risk factors. Magnetic resonance imaging showed a sellar and suprasellar mass, thought to be a pituitary macroadenoma. He underwent endoscopic transsphenoidal adenectomy and cystic fluid was seen intraoperatively. Microbiology analysis showed Staphylococcus Aureus, and a course of intravenous ceftriaxone was commenced. Histopathology reported no evidence of adenoma and impression was of a pituitary abscess. Following transsphenoidal resection and commencement of antibiotic therapy, the bitemporal hemianopia resolved. We therefore report a rare case of primary pituitary abscess and emphasise the importance of including this condition as a differential diagnosis in any patient with a visual deficit or new pituitary lesion.

Papillary craniopharyngioma coexisting with an intratumoral abscess in a pediatric patient: A case report and review of the literature

Craniopharyngiomas are benign neoplasms with two histological subtypes: adamantinomatous and papillary. Papillary craniopharyngiomas are rare in children, and those with a pituitary abscess within are even rarer. Herein, we present the case of a 14-year-old boy with a papillary craniopharyngioma and a coexisting intratumoral abscess, who was hospitalized for persistent pyrexia, polyuria, and polydipsia. The absence of calcification on computed tomography, high signal intensity inside the tumor on diffusion-weighted imaging, and clinical findings such as fever, a high inflammatory response, and meningitis, as well as short-term morphological changes on imaging, could aid in diagnosis.