Metastatic basal cell carcinoma with squamous differentiation: Report of a case with response of cutaneous metastases to electrochemotherapy

Background: Metastatic basal cell carcinoma is a rare disease with poor prognosis. Palliative therapeutic approaches include surgery, radiotherapy, and/or chemotherapy. These treatment modalities are invasive and risky and associated with relevant adverse effects. Electrochemotherapy is a recently described therapy that relies on the permeation of cancer cell membranes by electrical pulses to enhance cytotoxic drug penetration. It has been successfully used in the treatment of primary and metastatic skin cancers. We report a case of metastatic basal cell carcinoma in which electrochemotherapy was effective in inducing local regression of skin metastases. Observations: A 75-year-old man presented with a pigmented, deeply infiltrating nodule in the right axilla manifesting as basal cell carcinoma with squamous differentiation at histopathologic examination. Despite 2 wide surgical resections involving lymphadenectomy with axillary vein substitution and systemic chemotherapy, a progressive metastatic spreading, both cutaneous and visceral, occurred in the following 2 years. Three successive sessions of electrochemotherapy with bleomycin sulfate were then performed on isolated skin metastases. The treatment was well tolerated and led to a rapid clinical and histologic regression of the treated lesions. Conclusion: Electrochemotherapy is an effective and well-tolerated adjunct to the therapeutic options in metastatic basal cell carcinoma, characterized by an advantageous risk-benefit ratio and minimal downtime.