Breast

Question 1

What should always be considered with a spindle cell lesion in the breast

Answer 1

Metaplastic Carcinoma should be ruled out
Use CK 7, CK 5/6 (should be positive on this)
Mostly spindle cells will appear high grade if carcinoma but can appear low grade

Question 2

What is the differential diagnosis for a fibrotic lesion in the breast

Answer 2

Gynaecomastia (look for lack of normal lobules, ie haphazard collection of cystic or atrophic glands in fibrotic stroma)

PASH (look for clefts around ducts containing endothelial cells)

Sclerosing Adenosis (lobules with increased number of tubules like adenoma but many compressed in a hyaline fibrotic stroma. Glands at the periphery may not be compressed.)

Diabetic or Lymphocytic Mastopathy (ducts or glands surrounded by dense lymphocytic infiltrate in a fibrotic stroma)