Metastatic Basal Cell Carcinoma Arising From a Primary Cutaneous Carcinosarcoma

Area of Science:

• Oncology
• Dermatology
• Genetics

Background:

• Primary cutaneous carcinosarcoma is a rare tumor with epithelial and mesenchymal components.
• Basal cell carcinoma (BCC) is a common skin cancer, but its association with carcinosarcoma is infrequent.

Observation:

• A 56-year-old man presented with a scalp lesion containing both BCC and a sarcomatous component.
• The patient later developed metastatic BCC to the scalp, lymph nodes, lung, and rib.

Findings:

• Next-generation sequencing of lung metastasis revealed a PTCH1 gene mutation.
• The patient was successfully treated with vismodegib, a hedgehog pathway inhibitor.

Implications:

• This case is unique as metastatic BCC originated from a primary carcinosarcoma with a basal cell component.
• The findings suggest the efficacy of targeted therapies like vismodegib for rare carcinosarcoma subtypes.
• Further research into the pathogenesis and clinical course of these rare tumors is warranted.