metaplastic carcinoma

met·a·plas·tic car·ci·no·ma

a carcinoma in which some of the tumor cells are spindle shaped, suggesting a sarcoma, or in which the stroma shows foci of bone or cartilage; such carcinomas occur in the upper respiratory or alimentary tract or in the breast.

metaplastic carcinoma (breast)

A heterogeneous group of basal phenotype tumours that comprise ± 1% of invasive breast carcinomas, which are characterised by an intimate admixture of adenocarcinoma with dominant areas of spindle cell, squamous and/or mesenchymal differentiation.
DiffDx
Metastatic carcinoma, primary sarcoma, fibromatosis, phyllodes tumour.
Metaplastic carcinoma types
• Pure epithelial—Squamous cell carcinoma, adenocarcinoma or adenosquamous with spindle differentiation.
• Mixed epithelial-mesenchymal—Carcinoma with chondroid or osseous metaplasia, carcinosarcom.

met·a·plas·tic car·ci·no·ma

(met'ă-plas'tik kahr'si-nō'mă) A malignancy in which some of the tumor cells are spindle shaped, suggesting a sarcoma, or in which the stroma shows foci of bone or cartilage.