Primary epithelial-myoepithelial carcinoma of the pituitary gland

Primary salivary gland-like tumors of the sella are rare and often challenging to diagnose. They reportedly derive from serous and mucinous glands that remain trapped in the infundibulum during embryogenesis. We report a 68-year-old man who presented with partial left third cranial nerve palsy, visual loss in the left eye without visual field defects, headache, weight loss and reduced muscle bulk. Neuroimaging studies demonstrated a solid and cystic, avidly enhancing lesion expanding the pituitary fossa and extending to the left cavernous sinus. The patient underwent craniotomy and the tissue removed showed features of epithelial-myoepithelial carcinoma similar to the salivary gland, skin and breast counterpart. No primary tumor was found outside the sella. The lesion behaved aggressively despite radio-chemotherapy and the patient died 22 months from the onset. The tumor showed a novel TP53 in-frame deletion (Gly154del) while no variants were found in H-RAS hotspot regions (codons 12, 13 and 61). Our report expands the spectrum of salivary gland-like tumors primarily occurring in the sella and emphasizes the need for specialist review of rare, non-neuroendocrine tumors of the pituitary and sella regions.