Pituitary Incidentalomas are Different in an Oncology Setting

Purpose: Pituitary incidentalomas (PIs) are pituitary lesions identified on imaging performed for unrelated reasons. Although well described in the general population, data on PIs in cancer patients remain scarce. We aimed to describe the etiology, clinical presentation, and follow-up of PIs in an oncological setting. Methods: We conducted a retrospective observational study of all CT and MRI reports containing the terms “sella(r)”, “pituitary” or “hypophysis” between September 2008 and September 2021 in our cancer center. Data on imaging, pituitary function, and outcomes were collected and analyzed. Results: Forty-three patients (7.5%) had a PI on imaging exam. Complaints of headache (25.6%) and previously known non-pituitary lesions (25.6%) lead to most imaging requests. Adenomas were the most frequent diagnosis (55.8%), followed by pituitary metastases (18.6%), mostly found in patients with breast cancer. Patients with metastasis had larger lesions (p=0.017) and were more frequently diagnosed with hypopituitarism (p<0.001), when compared to adenomas. Malignant pituitary involvement was associated with a higher mortality at 3 months (OR 3.1; p=0.025). Conclusion: In our oncology center, we reported a higher prevalence of metastasis, with higher rates of hypopituitarism, when compared to benign lesions. Symptoms typically attributed to malignancy may conceal an underlying pituitary hormonal dysfunction, emphasizing the need for systematic endocrine evaluation. Awareness of these patterns may help in the development of tailored diagnostic and management strategies in this population.