The patient went on to have a biopsy.
MACROSCOPIC DESCRIPTION: A fragment of cream / grey-tan tissue, approximately 4 x 3 x 2 mm. (1.1) frozen section tissue.
MICROSCOPIC DESCRIPTION: The tumour consists of nests and strands of cells within a collagenous fibrous stroma. The tumour cells are generally polygonal in shape but in places they become elongate. In these areas a fascicular architecture with focal whorling is present. Cytoplasm ranges from minimal to moderate amounts of amphophilic material. The nuclei are rounded or somewhat elongate, with finely speckled chromatin. Sometimes small nucleoli are apparent. There is no tumour necrosis and mitotic figures are infrequent. Immunohistochemical stains show no staining for pituitary hormones, cytokeratins or epithelial membrane antigen. No convincing staining for chromogranin or synaptophysin is found. There is, however, strong nuclear and cytoplasmic staining for S100 with no staining for gp-100 or melan-A.
FINAL DIAGNOSIS: The morphologic and immunohistochemical features are in keeping with the rare entity of pituicytoma 1.
features images from this case