Imaging Characteristics of a Hypervascular Pituitary Spindle Cell Oncocytoma on Magnetic Resonance Imaging and Digital Subtraction Angiography.

Abstract

Spindle cell oncocytomas (SCOs) are rare neuroendocrine tumors of the posterior pituitary that are often misdiagnosed as nonfunctional pituitary tumors. Fewer than 50 cases of SCOs have been described in the literature, and many of these reports have documented the tumors to be hypervascular on imaging or histology. We present the first cerebral angiography imaging findings of an SCO before primary resection. The discovery of a prominent tumor blush, enlarged meningohypophyseal feeders bilaterally, and prominent tumor draining veins aided in preoperative planning and subsequent successful endoscopic transsphenoidal surgical resection. Despite being a rare entity, SCOs should be included in the differential diagnosis when working up a hypervascular sellar tumor. Flow voids may be present on initial magnetic resonance imaging evaluation. Subsequent digital subtraction angiography can be used to further investigate abnormal vasculature and aid in surgical planning.