Secondary Pituitary Abscess: A Rare Complication of Transsphenoidal Surgery for Pituitary Adenoma - Description of Two New Cases and Review of the Literature.

Background: Pituitary abscess (PA), a rare complication following transsphenoidal (TS) surgery for pituitary adenoma with an incidence of 0.2%, poses a significant risk; carrying potential morbidity, recurrence, and the necessity for reoperation. Timely suspicion, diagnosis, and treatment are imperative. Patients and Methods: We present two cases and provide a literature review on the symptoms, risk factors, diagnosis, treatment, and outcomes associated with secondary PAs following TS surgery for adenoma. Results: We identified 12 articles reporting a total of 45 cases, in addition to our 2 cases. The primary symptoms were headache and visual impairment, with no fever or specific infectious parameters observed. Predominant risk factors identified included cerebrospinal fluid (CSF) leakage and prior radiotherapy (RT). Our first patient, a 45-year-old male, presented 10 weeks after TS surgery with sudden-onset symptoms, whereas our second patient, a 64-year-old female, presented 22 years postoperatively. In the first case, intraoperative CSF leakage, with the patient's history of allergic rhinitis and frequent nasal irrigation possibly contributed to the development of abscess. In the second case, RT was considered a potential risk factor. Severe headache and subclinical signs of infection associated with a cystic lesion of the pituitary gland were common findings. Both patients underwent endoscopic TS drainage and received appropriate antibiotic therapy, resulting in complete recovery without recurrence. Conclusions: When faced with severe headaches in a patient with a history of TS surgery for a pituitary adenoma, coupled with radiological evidence showing a cystic appearance with peripheral enhancement, taking a proactive approach to promptly identify and intervene in secondary PAs is essential for mitigating potential complications and optimizing patient outcomes.