Nonfunctioning Ectopic Pituitary Adenoma: A Rare Case Report from Southern Asia

Ectopic pituitary adenoma (EPA) is an extraordinarily rare condition characterized by the presence of a pituitary adenoma outside the intrasellar region. Although EPA may share similarities with typical pituitary adenomas in morphology, radiological findings, immunohistochemistry, and hormonal activity, it can present with either nonspecific or specific endocrine symptoms. A 37-year-old female school teacher with persistent and worsening headaches underwent neuroimaging, which revealed a sizable extra-axial solid mass in the right parasellar region, extending into the cavernous sinus, base of the skull, and sphenoid sinus. This mass was initially indicative of a cavernous sinus meningioma. Laboratory investigations, including a pituitary hormone profile, yielded normal results. Despite the lack of typical symptoms, the patient underwent an elective right temporal craniotomy and subtotal tumor resection, which exposed both extra-axial and intra-axial components. Immunohistochemistry analysis confirmed the presence of a pituitary adenoma with atypical features. Postoperatively, the patient recovered well, and adjuvant stereotactic radiosurgery was used to address the residual lesion. During the 1-year follow-up, the patient remained free of symptoms. This case highlights the diagnostic complexities associated with nonfunctioning EPAs and underscores the importance of a comprehensive approach to ensure accurate diagnosis, effective treatment, and sustained patient well-being.