Merkel cell carcinoma metastatic to the transverse colon: disease free after six years - cure or just prolonged remission?

An Extraordinary Cause of Colonic Obstruction: Merkel Cell Carcinoma of Unknown Primary

Merkel cell carcinoma is an aggressive and rare neuroendocrine skin cancer with documented metastases to the liver, lungs, and, seldom, the gastrointestinal tract. Metastases to the colon are rare but are seen with primary skin lesions or recurrent disease. Presented is a patient with large bowel obstruction secondary to a large hepatic flexure mass. Pathologic workup revealed Merkel cell carcinoma, and a dermatologic evaluation did not identify a primary cutaneous lesion. This is the first reported case of Merkel cell carcinoma of unknown primary presenting as large bowel obstruction.

Mercurial Metastatic Merkel Cell Carcinoma: A Case of Colonic Involvement

Merkel cell carcinoma (MCC) is a neuroendocrine skin cancer that typically presents as a painless erythematous nodule on body surfaces visible to the sun. Metastatic disease is typical to the lymph nodes, liver, and lungs. There are previous case reports of patients with metastases to the gastrointestinal tract including the stomach, small intestine, and pancreas. To our knowledge, there are only rare occurrences of metastases to the colon. We report a patient with a history of MCC treated with chemotherapy who presented with hematochezia and underwent a colonoscopy that showed a partially obstructing, edematous, friable 7-cm circumferential mass in the transverse colon. Biopsy confirmed the diagnosis of MCC that metastasized to the transverse colon.

Recurrence of Merkel cell carcinoma in the gastrointestinal tract: a case report

BACKGROUND

Merkel cell carcinoma is a rare and aggressive skin malignancy that arises from primary neural cells and has a tendency for local recurrence and regional lymph node metastases. There are only a few cases in the literature reporting metastases of Merkel cell carcinoma to the gastrointestinal tract.

CASE PRESENTATION

We present a 70 year old Caucasian female with distant history of Merkel cell carcinoma who presented with iron-deficiency anemia. Colonoscopy performed later for the evaluation of anemia revealed 1 cm polyp in ascending colon which turned out to be the recurrence of Merkel cell carcinoma.

CONCLUSION

Metastatic Merkel cell carcinoma to the gastrointestinal tract or any other organ should be considered in patients with a history of Merkel cell carcinoma.