Multimodal Management of Merkel Cell Carcinoma (MCC) with Regional and Distant Metastasis: A Case Report

Case-Based Insights into Optimizing Patient Outcomes

Abstract

Background: Merkel cell carcinoma is a rare and fast-growing skin cancer, with a significantly poor prognosis, especially in cases where metastasis occurs. Globally there are approximately 0.7 cases per 100,000 people annually. It predominantly affects older adults and the major causative factor is Merkel cell polyomavirus (MCPyV) among 80% of MCC. Due to its aggressive nature, MCC has a high risk of metastasis and recurrence. The rarity of MCC has led to limited standard treatment guidelines, particularly in advanced cases involving distant metastasis. Case Description: This case describes about a 60-year-old male with a medical history of hypertension and type 2 diabetes mellitus managed for the last decade with regular medications who presented to the outpatient department (OPD) with a complaint of rapidly growing, painless nodule on his right cheek. The nodule was diagnosed as MCC following a skin biopsy and detection of MCPyV through PCR test. Further imaging revealed metastasis in the reginal lymph node and no distant metastasis. Surgical excision of the primary tumor, right parotidectomy, and selective neck dissection was done which is followed by adjuvant radiation therapy. Despite initial successful treatment, the patient later developed distant metastasis to the liver and subsequently to the brain, after continued aggressive treatment including immunotherapy with pembrolizumab and stereotactic radiosurgery. Conclusions: This case highlights the challenges of managing advanced MCC, even with multimodal treatment approaches. The development of liver and brain metastases significantly worsened the prognosis, highlights the need for continued research into novel therapeutic strategies and the identification of biomarkers to predict treatment response