Basal cell carcinoma with neuroendocrine differentiation arising in a scar: A case report.

Basal cell carcinoma (BCC), the most common cutaneous malignant tumor, may display neuroendocrine differentiation in very rare instances. We here describe a case of a BCC with neuroendocrine differentiation that arose in a scar resulting from a trauma 75 years earlier. Neuroendocrine differentiation was proven by immunohistochemistry and electron microscopy. The simultaneous occurrence of BCC development in a scar and neuroendocrine differentiation is quite rare.