Metastatic Basal Cell Carcinoma With Unusual Molecular Genetics Findings.

Basal cell carcinoma (BCC) rarely metastasizes to other parts of the body. When metastasis occurs, it usually involves regional lymph nodes. BCC lesions located in the head and neck region have been shown to spread to cervical lymph nodes. Here, we present a case of a slow-growing lesion on the scalp that was diagnosed as a case of BCC. Metastasis to the level V cervical lymph nodes was already present at the time of diagnosis. The patient was managed with complete excision of the lesion, along with a neck dissection for level V lymph nodes, and adjuvant chemotherapy with Vismodegib. Molecular pathology results revealed a unique pattern, comprising the fusion of HMGA2-CHMP1A genes and a mutation involving a premature termination codon (PTC) in the CDKN2B gene. The post-operative work-up revealed a hypermetabolic nodule in level IIB lymph which is more likely inflammatory rather than metastatic. However, considering the possibility of metastasis, the patient is being followed up by a multi-disciplinary team (MDT) for evaluation of level IIB cervical lymph nodes. This case highlights the diagnostic and therapeutic challenges that may arise in rare cases of BCC with metastasis.