Beyond the skin - metastatic basal cell carcinoma in the stomach: A case report.

[BACKGROUND] Basal cell carcinoma (BCC) is the most prevalent skin cancer, characterized by indolent growth and low metastatic rates. When metastatic BCC (mBCC) does occur, it most commonly involves lymph nodes, lungs, and bones, with metastases to other sites being exceptionally rare. This case reports the first documented instance of mBCC to the stomach, highlighting the importance of considering atypical metastatic sites, and the challenges associated with diagnosis and management.

[CASE SUMMARY] A 52-year-old male with recurrent BCC and known mBCC to the bone presented with progressive dysphagia, cranial neuropathies and generalized weakness. He had been treated with immune checkpoint inhibitors, with intermittent therapy modifications due to treatment related toxicities. His past history was notable for malignant perineural invasion, radiotherapy for osseous metastases, immune checkpoint inhibitor-induced enteritis, and osteonecrosis of the jaw. Gastroscopy revealed subepithelial gastric lesions, and biopsies confirmed mBCC - a previously unreported site of disease dissemination. A multidisciplinary team involving gastroenterology, oncology, neurology, and palliative care guided his management. Given his declining functional status and poor prognosis, he was ultimately transitioned to hospice care.

[CONCLUSION] Clinicians should consider atypical metastatic sites in advanced BCC. A multidisciplinary approach remains essential for timely diagnosis and coordinated management.