Cutaneous basal cell carcinoma with distant metastasis to thorax and bone: A clinicopathological and immunohistochemical study of 15 cases

Basal cell carcinoma (BCC) is the most common cutaneous malignancy and is characterized by a high cure rate after local excision. Metastatic BCC (mBCC) is an exceedingly rare event, associated with poor prognosis. We report clinicopathological and immunohistochemical features of 15 mBCC metastatic to the thorax and bone. The patients were 14 males and one female with a mean age at diagnosis of cutaneous BCC of 53 years and at metastasis of 64 years. Primary BCC were primarily located in the head and neck or torso and microscopically included five nodular, three basosquamous, three mixed, and one each of superficial, infiltrative, micronodular, and morpheaform types. Eleven cases metastasized to the lung, three to the bone, and one to the heart. Immunohistochemically, 70% of mBCC were positive for bcl-2, 81% for BerEP4, and 0% for EMA. Treatment consisted of surgery and/or chemotherapy or radiation. Eight patients died at a median interval from metastasis to death of 20 months, and seven were alive at a median interval of 30 months. BCC metastatic to the thoracic organs or bone is rare, mainly affecting older white males. BCC when metastatic commonly affects the lung or bone but rarely the heart. Our results suggest a slightly better prognosis than previously reported, possibly due to improved multimodal treatment strategies. Metastasis from BCC should be considered in a patient with metastatic disease of unknown primary and a history of BCC. Immunohistochemistry may be helpful to reach a final diagnosis.