Granular cell tumour of the pituitary region
Rare, usually benign TTF-1–positive posterior pituitary tumour that commonly presents as a solid enhancing stalk/suprasellar mass.
Warning
Not the same beast as “Abrikossoff” Granular cell tumour (Schwann-cell, tongue/breast/skin). This one is a posterior pituitary (pituicyte-derived) tumour and sits in the stalk/posterior lobe family with pituicytoma and spindle cell oncocytoma.
Typical clinical clues
- Symptoms from mass effect: visual disturbance/headache; endocrine: hypopituitarism ± mild hyperprolactinaemia (stalk effect).
Imaging features
- Location: posterior lobe and/or infundibulum, often sellar–suprasellar with stalk involvement; may lose the normal posterior pituitary bright spot.
- MRI signal: classically T1 isointense and T2 iso-to-hypointense
- Enhancement: usually avid enhancement (often fairly solid).
- CT: can be relatively hyperdense; calcification is uncommon.
Differentials
- Pituicytoma / spindle cell oncocytoma: same family + similar imaging → often indistinguishable radiologically; pathology (TTF-1+, other markers) decides.
- Meningioma (tuberculum/diaphragma): dural tail, broad dural base, hyperostosis.
- Hypophysitis (incl. IgG4/drug-related): stalk thickening + inflammatory context; DI more common.
- Germinoma / LCH / metastasis: stalk + DI + systemic clues; consider age and extracranial disease.
- Craniopharyngioma: cystic + calcified pattern, different texture.
