Merkel cell carcinoma and delayed diagnosis: a clinical alert

Mariana A. Santos, Department of Dermatology, Hospital de Base, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil Julia C. K. El Dib, Department of Dermatology, Hospital de Base, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil Bruna M. Batista, Department of Dermatology, Hospital de Base, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil Fernanda R. de O. Mattar, Department of Dermatology, Hospital de Base, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil Paula P. Pretti, Department of Dermatology, Hospital de Base, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil João R. Antônio, Department of Dermatology, Hospital de Base, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil Mariana S. Kagohara, Department of Dermatology, Hospital de Base, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil

Merkel cell carcinoma (MCC) is a rare but highly aggressive neuroendocrine skin cancer with a mortality rate higher than melanoma. It primarily affects elderly patients with risk factors such as chronic sun exposure, immunosuppression, or previous skin cancers. The case describes an 80-year-old male with multiple ulcerated skin lesions and widespread metastasis, diagnosed at an advanced stage (stage IV). Due to the disease’s extent, curative treatment was not possible, and palliative chemotherapy was initiated but discontinued due to severe toxicity. This case highlights the rapid progression of MCC, the challenges in early diagnosis, and the critical importance of timely recognition to allow for more effective treatment and improved patient survival.

Keywords: Merkel cell carcinoma. Skin neoplasm. Early diagnosis. Elderly. Metastasis. Immunohistochemistry.