A hysterectomy specimen from a 58-year-old woman shows a malignant mixed Mullerian tumour (carcinosarcoma) containing both malignant glandular epithelium and a malignant stromal component with cartilage formation. When this tumour metastasises, which component is typically found in the metastatic deposits?

• A Both components in equal proportion
• B The heterologous sarcomatous component
• C The carcinomatous (epithelial) component ✓
• D Neither component, as it spreads only by local extension

Explanation

Carcinosarcoma is now regarded as a metaplastic high-grade carcinoma, and its behaviour follows the epithelial component. Metastases almost always contain carcinoma alone, reflecting the clonal origin of both components from a single transformed epithelial precursor. The homologous or heterologous sarcomatous element, including cartilage or skeletal muscle, usually remains confined to the primary tumour. This is why treatment follows high-grade carcinoma protocols rather than sarcoma protocols.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.