Granular cell tumour

The granular cell tumour is a rare beast.

General

• Rare.
• Usually benign.
• May mimic (well-differentiated) squamous cell carcinoma - histopathologically.
  • There is a well-described phenomenon called pseudoepitheliomatous hyperplasia.

Gross

• Yellow nodule.

Note:

• DDx of yellow nodule: granular cell tumour, lipoma, xanthoma.

Microscopic

Features:

• Abundant eosinophilic granular cytoplasm.
  • Granules:
    • Size: 1-3 micrometers.
    • Poorly demarcated.

Special stains

• PAS +ve.

IHC

Features:

• S100 +ve.
• CD68 +ve (cytoplasmic).
• Vimentin +ve (membranous).

Images:

• GCT - skin (WC).
• GCT - S100 (WC).

See also

• Esophagus.