Unusually high frequency of pituitary abscess in the post-COVID-19 era: insights from a single-center experience

Pituitary abscess (PA) is a rare but life-threatening condition, accounting for < 1% of pituitary lesions. At a single center, 140 endoscopic transsphenoidal surgeries for pituitary lesion resection were performed since 2018, with 13 patients diagnosed with PA at an unusually high incidence rate of 9.2%. The aim of this study was to characterize the diagnostic criteria, symptoms, microbiological profile, radiological features, and endocrinological characteristics of PA, while exploring potential reasons for the increased frequency of PA in the post-COVID-19 era.

A single-center retrospective review of patients with primary and secondary PA from 2018 to 2024 was conducted. Diagnosis was confirmed through intraoperative pus detection or laboratory confirmation. A univariate analysis was performed to assess factors associated with postoperative hormonal disorders and the accuracy of MRI-based preoperative diagnosis. Univariate ANOVA was used for quantitative variables, and categorical variables were analyzed using the chi-square and Fisher's exact tests.

Of 13 patients (9 female, mean age 56.5 years) included in the analysis, risk factors were present in 30.8%. The most common symptoms at presentation were visual disturbance (69%), headache (53%), and pituitary insufficiency (38%). A correct preoperative diagnosis was made via MRI, based on characteristically high signal intensity on T1-weighted images, for 69% of patients. No infectious symptoms were observed. A bacterial agent was identified in 84.6% of patients, with gram-positive bacteria more common. Treatment included pus evacuation and postoperative antibiotics. Headaches resolved for all patients and visual deficits improved in 7 of 9 patients, but endocrine abnormalities persisted or newly developed in some cases. One patient (7.7%) experienced recurrence, and no deaths were recorded. The study period was from 2018 to 2024, with a substantial increase in the frequency of PA after 2020 (post-COVID-19 era).

MRI features of PA can mimic other pituitary pathologies. Pus evacuation remains the primary treatment. Preoperative antibiotics might be unnecessary in stable patients without signs of infection. The incidence of PA could be higher in the post-COVID-19 era, possibly due to immune system changes and healthcare disruptions.