Giant Prolactinoma Presenting As a Base of Skull Tumor With Nasopharyngeal Extension: A Potential Diagnostic Pitfall in Neuroendocrine Lesions of the Base of Skull.

Pituitary adenomas presenting in uncommon anatomical locations are commonly misdiagnosed. Dramatic clinical presentation with hemorrhage and infarction, along with a lack of endocrine symptoms may further confound the diagnosis in some patients as illustrated in one of our two previously reported cases of non-small cell neuroendocrine carcinoma of the sinonasal tract and nasopharynx. This report presents the clinical progress of case number 2, which has a revised diagnosis of giant lactotroph pituitary adenoma. Common clinical, radiological and pathological pitfalls in diagnosis of neuroendocrine neoplasms of the sinonasal tract and base of skull are discussed.