Merkel cell carcinomaMerkel cell carcinoma (MCC) is a rare and aggressive tumor associated with advanced age and immunosuppressionImmunosuppression. The majority of MCC tumors (~ 80%) are associated with the clonal integration of Merkel cell polyomavirusMerkel cell polyomavirus (MCV) DNA and expression of MCV viral oncoproteins. However, the pathogenesis of non-viral MCC is associated with the accumulation of somatic mutations caused by UV radiationRadiation. MCC has a high recurrence rateRecurrence rates (~ 40%) and propensity for regional and distant metastases. In the USA, the incidence of MCC is increasing due to an aging population. Surgery is the preferred treatmentTreatment for localized MCC. In comparison to wide local excisionWide local excision (WLE), Mohs micrographic surgeryMohs micrographic surgery (MMS) is one solution to eliminate the tumor and preserve tissue. RadiationRadiation of the primary tumor site and/or regional lymph node basin may favorably improve recurrence ratesRecurrence rates. Moreover, chemotherapy is an option for inoperable or metastatic disease, and immunotherapy has recently shown potential for treatmentTreatment of advanced MCC. Despite the poor prognosis, especially in metastatic MCC, a more comprehensive understanding of tumorigenesis, diagnosis, and treatmentTreatment algorithms can improve survival outcomes.