Malignant Chondroid Syringoma: A Report of Two Cases with a Sarcomatous Mesenchymal Component

Malignant chondroid syringoma (MCS; malignant mixed tumour) is a rare neoplasm typically arising on the extremities and trunk. We are report 2 unique cases of MCS, one occurring on the scalp of a 78-year-old man and the other on the trunk of a 72-year-old woman. Both tumours harboured malignant epithelial and malignant mesenchymal components. The latter was represented by liposarcoma in the first case. The malignant components of the second tumour comprised spindle cell squamous cell carcinoma (SCC) and osteosarcoma. Origin from a pre-existing benign chondroid syringoma was clearly evident in both neoplasms. The presence of heterologous malignant mesenchymal components, however, is hitherto unreported in the context of MCS, while a spindle cell SCC component is exceptionally rare. The 2 cases presented herein highlight an expanded morphological spectrum of MCS, with resultant blurring of the boundaries between MCS and cutaneous carcinosarcoma.