Coexistence of a Basal Cell Carcinoma and Leiomyosarcoma

The document reported a unique case of a 63-year-old woman with a collision tumor consisting of basal cell carcinoma (BCC) and cutaneous leiomyosarcoma (LMS), marking the first known instance of this combination. BCC is a common non-melanoma skin cancer, while LMS is a rare mesenchymal tumor that can metastasize. The study highlighted the importance of recognizing such coexistence, as BCC is typically slow-growing and rarely metastatic, whereas cutaneous LMS can metastasize and requires surgical intervention and long-term follow-up. The document discussed potential mechanisms for the coexistence, including the role of platelet-derived growth factor (PDGF) and the tumor microenvironment in promoting mesenchymal overgrowth. It also mentioned the possibility of epidermal induction changes contributing to the development of collision tumors. The study emphasized the need for pathologists to be aware of this potential relationship in diagnosis.