Pituitary abscesses: Clinical, radiological, ophthalmological, endocrinological and microbiological features in a case series of 5 patients

Introduction: Pituitary abscess is a rare pathological entity and may be encountered unexpected during surgery for intra- and suprasellar cystic lesions. Here we report our experience in a consecutive series of 5 patients, who underwent endoscopic endonasal transsphenoidal surgery (EETS).

Methods: From 01/2009 to 10/2012 5 patients with pituitary abscess were retrieved from our prospective data base of patients with perisellar lesions. Clinical signs, laboratory and MRI findings, results of pre- and postoperative endocrinological testing, microbiological testing and clinical course were analyzed. All patients had clinical, ophthalmological, endocrinological and MRI follow up 6 to 8 weeks after EETS.

Results: In this series the incidence of primary pituitary abscesses was 5% in a consecutive patient series with sellar pathologies. Headache was the primary symptom in all patients. No patient had clinical symptoms of an acute infection. One patient had a chronic sinusitis. Although all patients reported decreased vision, preoperative visual disturbance was detected in only 2 patients. In 3 cases a pituitary apoplexy was suspected. Hypopituitarism was detected in 4 patients (panhypopituitarism in one). In all cases MRI depicted a cystic lesion with a contrast enhancing capsula with suprasellar extension. Microbiology revealed Staphylococcus epidermidis in 2 and Staphylococcus captis, Proteus mirabilis and Escherischa coli in 1 patient each. Headache improved in all patients postoperatively. In only 1 patient new diabetes insipidus occurred postoperatively. One patient with adrenocorticotropin deficiency had an improvement postoperatively. None of the patients had recurrent disease.

Discussion: A pituitary abscess should be considered as differenzial diagnosis in patients with cystic circular contrast enhancing lesions even in the absence of clinical symptoms of infection. After surgical treatment no recurrences occurred and treatment related complications were low.