Sellar collision tumor: Pituitary adenoma combined with Rathke's cyst

A 22-year-old woman was admitted to our institution with the chief complaint of intermittent headache for a course of one week. A mass was detected in the pituitary gland region by computed tomography (CT). Despite thorough physical and biochemical examinations, no abnormalities were detected. Coronal and sagittal non-contrast enhanced T1-weighted image (T1WI) through the Sella turcica showed a well-defined 2.1 cm × 1.5 cm × 2.9 cm mass with a clear margin. The inferior part of the mass demonstrated an equal T1WI signal, while the superior part showed a high T1WI signal, reminiscent of a snowman wearing a white cap (Fig. 1A, B; white arrow). Upon review of the enhanced T1WI images, it was found that the lesion was likened to a ghost (Fig. 1C, blue arrow), of which the body exhibited obvious reinforcement with two non-enhancing eyes and whose face was unenhanced. The mass was successfully removed through a transsphenoidal operation. Microscopic examination of the lower component revealed the presence of round or polygonal pituitary adenoma cells with distinct boundaries and a lamellar distribution pattern. The nuclei were round in shape and the cytoplasm abundant with nucleoli (Fig. 2A). On the other hand, microscopic examination of the upper component revealed the presence of a homogeneously red stained cyst lining with ciliated columnar epithelium (Fig. 2B). The pathological features recognized in the mass supported a diagnosis of pituitary adenoma complicated by the presence of Rathke's cyst. The patient made a full recovery post-surgery with no complications. Fig. 2 View Large Image Figure Viewer Download Hi-res image