33. Basal cell carcinosarcoma: a report of three cases and review of the literature

The term ‘carcinosarcoma’ has been used for a range of morphologically distinct biphasic cutaneous tumours. These include squamous cell carcinoma with spindle cell or sarcomatoid components, malignant adnexal tumours with epithelial and mesenchymal elements and Merkel cell carcinoma with sarcomatoid components. The term has also been used to refer to monophasic carcinomas with a ‘sarcoma-like’ morphology, tumours also termed ‘sarcoma-toid carcinoma’. Lesions showing basal cell carcinoma with sar-comatoid stroma are rare, with only small series and single cases reported. We report the clinical and pathological features of three cases of this entity, retrieved from the files of three pathology practices, and review reported cases from the literature. All three of our cases occurred on the ear of elderly men and showed an epithelial component with typical features of nodular basal cell carcinoma, with an additional component of infiltrating basal cell carcinoma in one. In addition, all three showed a distinct admixed component of spindle cell sarcoma without features of specific differentiation. In one case there was a minor admixed component with an osteo-sarcomatous appearance, and one showed scattered tumour giant cells. Despite relatively high reported rates of local recurrence and metastasis for ‘carcinosarcoma’ as an unrefined entity, it appears that the sub-group of basal cell carcinosarcoma has a relatively good prognosis, with adequate local excision being curative in the majority of cases. Recognition of this entity is critical for accurate diagnosis and its separation from other types of carcinosarcoma may have significant prognostic implications.