Merkel Cell Carcinoma: Case Report and Bibliographic Review

Abstract

Introduction: Merkel cell carcinoma (MCC) is characterized as a malignant trabecular neoplasm of the skin. The most common sites of lesions are areas frequently exposed to the sun, thus regions such as head, neck and upper limbs. The aim of this study is to report the clinical case of a female patient assisted in a Teaching Hospital in the State of São Paulo, with a lesion in the left gluteal region, unusual to what is found in the literature.
Case Report: An 87-year-old female patient, who underwent excisional biopsy of a lesion on her left buttock, with an anatomopathological (AP) diagnosis of MCC, was also submitted to a control image, which showed a new lesion in the lymph node chain, and underwent a new surgical procedure, which was unsuccessful.
Discussion: Most patients have local disease, but MCC has a high rate of metastasis, with the main sites of secondary lesions being skin (28%), regional lymph nodes (27%), liver (13%), lung (10%), bone (10%), and brain (6%). As evident in the literature, the diagnosis of the patient was made by immunohistochemical analysis, through the positive expression of CK20, chromogranin and synaptophysin, and the extent of disease evaluated by computed tomography. Wide local excision and adjuvant radiotherapy remain the mainstay of MCC treatment, but many studies show promising results with the use of monoclonal antibodies, such as avelumab, which was not used in the case reported. Although MCC is rare, despite the high recurrence rate and poor prognosis, early diagnosis and treatment are essential to prevent and combat the progression of metastatic disease, the main factor in the decrease in overall survival of patients.
Conclusion: MCC is still a challenge for the medical field, since this neoplasm has a high potential for recurrence and metastasis. However, late diagnosis and limited and delayed treatment contribute to a higher lethality rate.