RCPA Examinations in Anatomical pathology - Questions ... - Rcpa.tv

Case 1: Female 36 – suspicious
lesion on mammography
• MICROSCOPIC
• The breast tissue contains a well circumscribed invasive tumour. There is one component of the tumour where
the cells are arranged in large nests separated by fibrous bands. . Within the cell nests there is a predominance of
small basaloid cells many of which surround aggregates of eosinophilic homogeneous material. There are also
true lumens present lined by cells with more abundant eosinophilic ic cytoplasm. Surrounding this area of nested
tumour there are infiltrating small tubules, nests and trabeculae e of tumour cells. Again these consists of both
basaloid cells and cells with more abundant eosinophilic cytoplasm surrounding true lumens.
• Comment
• The presence of small basaloid cells associated with more epithelial appearing cells and aggregates of eosinophilic
material indicates an adenoid cystic carcinoma. The differential l diagnosis includes an infiltrating cribriform
carcinoma and in places the clearing around some of the infiltrating ting nests raises the possibility of a micropapillary
carcinoma.
• Investigations
• Alcian blue, , PAS, immunoperoxidase stains for oestrogen and progestagen receptors
• The eosinophilic material present should show positive staining with Alcian blue and be negative for PAS with the
true glandular lumina showing positive staining with PAS. Immunoperoxidase stains for oestrogen and
progestagen receptors should be negative in adenoid cystic carcinoma with positive p
staining in an infiltrating
cribriform carcinoma and frequent positive staining in a micropapillary carcinoma.
• SUMMARY/ Preferred diagnosis
• Breast: Adenoid cystic carcinoma