Pituicytoma

Pituicytoma is a neuropathology tumour in the [neurohypophysis.

General

Features:

• Low-grade glial neoplasm originating in the neurohypophysis.

Grading:

• WHO grade I.
• ICD-O: 9432/1.

Gross

• Adherent to other sellar structures.
• Solid.
• Well-circumscribed.

Microscopic

• Solid compact growth pattern.
• Bipolar spindle cells with distinctive cell borders.
• Rare mitoses.
• Few intercellular reticulin.

IHC

• GFAP: variable.
• S-100+ve.
• EMA: patchy.
• TTF1+ve.
• Synaptophysin -ve.
• Mib-1: low.

DDx:

• Pilocytic astrocytoma (Rosenthal fibers, eosinophilic granular bodies)
• Normal neurohypophysis
• Spindle cell oncocytoma

Images

• 

  Pituicytoma. (WC)

• 

  TTF1 in a pituicytoma. (WC)

Note: It is thoought that Spindle cell oncocytomas and granular cell tumors of the pituitary are variants of pituicytoma.

See also

• Neuropathology tumours.
• Pituitary gland.