Basal cell carcinoma with progression to metastatic neuroendocrine carcinoma: Case report and review of the literature

Abstract

Merkel cell carcinoma (MCC) or primary cutaneous neuroendocrine carcinoma is a malignant tumor considered to demonstrate differentiation towards Merkel cells that are present at the base of the epidermis or around the apical end of some hair follicles and are thought to play an yet uncertain role in sensory transduction. Here we present the case of a 54-year-old female with a basal cell carcinoma (BCC) of the skin with neuroendocrine features (positivity for chromogranin) that has evolved during multiple recurrences and radiotherapy into a high-grade neuroendocrine carcinoma with morphologic and immunohistochemical features of MCC (trabecular and nesting arrangement, positivity for chromogranin, cytokeratin 20, neuron specific enolase, and also neurosecretory granules on electron microscopy). The progression from a chromogranin positive basal cell carcinoma of the skin, to a high grade neuroendocrine carcinoma demonstrates the potential for cross differentiation among skin tumors.

Keywords

• Merkel cell carcinoma, basal cell carcinoma, neuroendocrine