Monarch Disease Ontology identifier MONDO_0003256 (neurohypophysis granular cell tumor) is a generally benign intrasellar and/or suprasellar mass arising from the neurohypophysis or infundibulum. It is composed of nests of large cells with granular, eosinophilic cytoplasm due to abundant intracytoplasmic lysosomes. It generally has a slow progression and lacks invasive growth. (Adapted from WHO). Also known as: granular cell tumor of Neurohypophysis, granular cell tumor of neurohypophysis, granular cell tumor of the Neurohypophysis (WHO grade I), granular cell tumor of the neurohypophysis, granular cell tumor of the posterior pituitary gland, granular cell tumour of Neurohypophysis, granular cell tumour of neurohypophysis, granular cell tumour of the Neurohypophysis (WHO grade I).