277 Merkel cell carcinoma: Preparing to go the distance Mohan ARUMUGAM 1 *, Adawiyah JAMIL 1 , Rayhan Aghani AMISENO 1 , Nurwahyuna ROSLI 2 , Nordashima ABDUL SHUKOR 2 1 Department of Internal Medicine and 2 Department of Pathology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia. Abstract Introduction: Merkel cell carcinoma (MCC) is a rare and aggressive malignancy of the skin, with poor clinical outcomes. Typical conditions include a rapidly growing, solitary dome-shaped, violaceous nodule. Several root causes have been identifed - sun exposure, age, lighter skin, immunocompromised state, and polyomavirus infection. Wide local excision is the best treatment. The tumour is radiotherapy-responsive. However, the success rate of the treatment with chemotherapy is rather limited. Immunotherapy has shown promising results. Early detection is important to prevent morbidity and mortality. Case Report: In this literature work, we reported on a particular case of MCC, as exhibited by an 84-year-old Chinese woman, and discussed the clinical features and management of MCC. Discussion: We highlighted that MCC cases have a link to the polyomavirus 5. Patients who were identifed with the Polyomavirus 5, and underwent immunotherapy, were seen to depict much better prognosis. Keywords: Merkel cell carcinoma, neuroendocrine tumour, Polyomavirus CASE REPORT Malays J Pathol 2020; 42(2): 277 – 281 *Address for correspondence: Mohan Arumugam, Department of Internal Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur; Tel: 03-91455555 ext:6075; Fax: 03-91456679; Email: mo- han@ppukm.ukm.edu.my INTRODUCTION Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine cutaneous malignancy. 1 It affects 0.6 per 100,000 people per year, in the United States, 1.6 per 100,000 people per year in Australia, and 0.3 per 100,000 people per year in Sweden. 2,3 In Malaysia, only 6 cases were reported in the Malaysian Cancer Registry between 2007 and 2011. 4 The 5-year relative survival rate stands between 30-64%, depending on the stage at which diagnosis takes place, as well as the site of the tumour. 5 MCC is typically presented as a solitary nodule in sun-exposed areas, which may be mistaken for a benign lesion during the initial presentation. 1 It also typically occurs amongst the elderly with light skin and immunocompromised states. 1 MCC was frst introduced by Toker in 1972. 1,5 While it was initially thought that MCC arose from Merkel Cells in the epidermis, this was now found to be less likely. 1 This point has been further elaborated in the discussion. Recent advances describe an association with polyomavirus, with one study reporting that as many as 8 out of 10 cases were positive for polyomavirus. 1,3,5,6 CASE REPORT An 84-year-old Chinese woman was presented to the dermatology clinic with a 4 months’ history of an ulcerated nodule in her left arm. She described the lesion as a pruritic pinkish nodule at frst, which later become ulcerated. It was non-tender. She did not have constitutional symptoms, or a history of skin trauma prior to the development of the nodule. There was no family history of cancer either. There was no history of allergies, and she denied excessive sun exposure. She did not use any topical or traditional medication on the skin before the lesion appeared. She had a long-standing type II diabetes mellitus, and hypertension for over 40 years. She also had diabetic retinopathy, stage IV chronic kidney disease (CKD) stage IV (EGFR 22). However, she refused renal replacement therapy. She had generalised dry skin and pruritus due to her CKD over the last 1 year or so. She required no medications for her diabetes, and hypertension over the past 8 months. Prior to