Metastatic Large Cell Neuroendocrine Carcinoma of the Lung Mimicking a Merkel Cell Carcinoma

of the lung is a newly recognized clinicopathologic entity and defined as a poorly differentiated and high-grade neuroendocrine tumor that stands morphologically and biologically between atypicall carcinoid and small cell lung carcinomal. Histopathologically, most LCNECs revealed a marked decrease in or a loss of organoid architecture and could be mistaken for poorly differentiated adenocarcinoma or squamous cell carcinoma2,3. Cutaneous metastasis of pulmonary cancer is common as shown in its rate up to 1.5 to 2.6% and may be presented as a first sign of cancer4, 5. Furthermore, the neuroendocrine features of cutaneous metastasis of LCNEC of the lung may be similar to Merkel cell carcinoma and other neuroendocrine carcinomas and therefore, it should be differentiated from them by histological and immunohistochemical studies. Thus, we herein report a case of cutaneous metastasis of LCNEC of the lung, previously misdiagnosed as squamous cell carcinoma.