RESIDENT CASE STUDIES

Week 10 June 23 - June 27, 2003: Case 1   

Table of Contents | List of Diagnoses | Case 1 | Case 2 | Case 3

71 year old female with right breast tumor 

Discussion
Metaplastic breast carcinomas (a.k.a., infiltrating ductal carcinoma with metaplastic component or sarcomatoid tumor of the breast) are rare neoplasms showing both carcinomatous and sarcomatous elements.¹ The typical cases are usually infiltrating ductal carcinoma with epithelial or mesenchymal metaplasia. The common denominator is the presence of metaplastic epithelial (squamous, etc.) or mesenchymal (spindle, chondroid or osseous) cells, usually in addition to an adenocarcinoma (even, if only focal) of the breast.² It must be differentiated from a true breast sarcoma with no adenocarcinoma component (has a worse prognosis), therefore, extensive sampling of metaplastic carcinoma may be needed to identify carcinomatous foci.

Although metaplastic carcinoma may stain for vimentin and sometimes with other mesenchymal markers, it is nearly always positive for cytokeratin in at least occasional cells.^3,4 

References:

¹Bellino R, Arisio R, D'Addato F, et al. Metaplastic breast carcinoma: pathology and clinical outcome. Anticancer Res. 2003 Jan-Feb;23(1B):669-73.

²Tavassoli FA. Pathology of the Breast (2nd ed.). (1999). McGraw-Hill.

³Wargotz ES, Norris HJ. Metaplastic carcinomas of the breast. V. metaplastic carcinoma with osteoclastic giant cells. Hum Pathol 1990;21:1142-1150 .

⁴Pitts WC, Rojas VA, Gaffey MJ, et al. Carcinomas with metaplasia and sarcomas of the breast. Am J Clin Pathol 1991;95:623-632.