Granular Cell Tumor of the Pituitary Stalk: A Rare and Benign Entity

Case report A 68-year-old man was examined for bitemporal hemianopsia and falling episodes. Computed tomography (CT) revealed a 32 mm spontaneously hyperdense suprasellar mass (Fig. 1). No calcification was noted. Complementary preoperative magnetic resonance imaging (MRI) showed a well delineated lesion with a nearly isointense signal on the T1-weighted images and a low signal intensity on the T2-weighted images. T1-weighted images following gadolinium administration demonstrated an inhomogeneous moderate to intense enhancement. Diffusion-weighted images showed a slight hypointensity with apparent diffusion coefficient (ADC) measured at 0.70 × 10−3 mm2/s (Fig. 2). The adjacent pituitary gland was estimated as normal. Meningioma was the first diagnostic hypothesis. A surgical intervention was planned but only subtotal resection was possible because of the lesion attachment to the chiasm and optic nerves. Histological examination provided the diagnosis of granular cell tumor (GCT). The postoperative course was uneventful and the patient’s progress was satisfactory. No evidence of recurrence has been identified after two years of observation.