A Case Report on Recurrent Merkel Cell Carcinoma with Metastasis to Colon Treated with Pembrolizumab

Case Report

Ann Hematol Oncol. 2021; 8(6): 1348.

A Case Report on Recurrent Merkel Cell Carcinoma with Metastasis to Colon Treated with Pembrolizumab

Shobha M1*, Baniya SS2, Sumit G3, Sunil S3, Yadav N4 and Joyson P5

1Department of Internal medicine, Guthrie Robert Packer Hospital, Sayre, PA, USA

2Department of Internal Medicine, State College, PA, USA

3Department of Medicine, Universal College of medical sciences, Bhairahawa, Nepal

4Department of Medicine, B.P. Koirala Institute of Health Sciences, Dharan, Nepal

5Department of Hemato-oncology, Guthrie Robert Packer Hospital, Sayre, PA, USA

*Corresponding author: Mandal Shobha, Department of Internal medicine, Guthrie Robert Packer Hospital, 126 hemlock road, apt 6, Sayre, PA 18840, USA

Received: April 14, 2021; Accepted: May 11, 2021; Published: May 18, 2021


Merkel Cell Carcinoma (MCC) is a cutaneous neuroendocrine cancer with a poor prognosis. It is characterized by a high rate of recurrence and metastases to regional as well as distant sites. Clinically, MCC often manifests as a single painless, hard nodule in the sun-exposed area. The diameter is often <2cm, but in few cases, it can be >2cm, with rapid growth and metastases to lymph nodes. MCC carcinoma is diagnosed in the advanced stage because of its resemblance with other skin cancers. Because of the aggressive nature of this cancer, the overall prognosis is found to be poor. In this case report, we report a 71-year-old gentle male who presented with a painless mass in the right axilla three years ago, was diagnosed with MCC of the skin and was treated with surgical removal of the mass together with radiation therapy. Two years later, the follow-up visit restaging PET CT scan was done and was found to have a new intense uptake in the soft tissue nodule adjacent to the proximal sigmoid colon. Biopsy confirmed the metastasis of MCC to the colon. We are reporting an uncommon location of MCC metastasis to the intestine for which he got treated with immunotherapy.

Keywords: Merkel cell carcinoma; MCC; Immunotherapy; Pembrolizumab


Merkel Cell Carcinoma (MCC) is rare and clinically aggressive skin cancer, with five years survival of nearly 18% for advanced-stage MCC [1]. MCC’s annual incidence is about 3 per 1000000 worldwide [2] and 0.79 per 100,000 in the United States [3]. It presents as a rapidly growing, firm, red to violaceous nodule [4]. Common risk factors associated with MCC are old age, fair-skin, immunosuppression, ultraviolet light exposure, polyomavirus infection [5,6]. It has a high propensity for recurrence because of metastases to distant sites. It rarely metastasizes to the gastrointestinal tract. Recently Immunotherapy like pembrolizumab has shown promising effects in the treatment of MCC. We report a 71-year-old male diagnosed with MCC of skin and was initially treated with surgical removal and radiation therapy. Later, on follow-up restaging, he was found to have a tumor recurrence in the colon. He got treated with Pembrolizumab.

Case Presentation

A 71-year-old white American male with a past medical history of hypertension, atrial fibrillation, cerebrovascular accident, coronary artery disease, and oxygen-dependent chronic obstructive pulmonary disease presented to the primary care physician with a painless mass in the right axilla three years ago. The mass was gradually increasing in size over one year and was non-tender without any pus or redness. He denied any surgery, trauma, insect bite, fever, or any history of any neoplastic process in the past. Family history was positive for some unknown cancer in grandfather. On exam, 1x1 cm mass was present in the right axillary region. On a detailed skin exam, there was no evidence of any sun-induced skin lesion or lymphadenopathy. Laboratories workup was within normal limits. Right axillary ultrasound showed an irregular hypoechoic mass measuring 4.7 x 5.9 cm (Figure 1).