Metastatic Merkel cell carcinoma masquerading as colon cancer

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.

Merkel Cell Carcinoma with Gastric Metastasis, a Rare Presentation: Case Report and Literature Review

INTRODUCTION

Merkel cell carcinoma (MCC) is an infrequent, but highly aggressive neuroendocrine neoplasm of the skin with a propensity for recurrence and metastasis. We report a rare case of gastric metastatic localization of this cancer by focusing on the diagnostic, clinical, and surgical approach to the patient.

CASE REPORT

Clinical presentation begins with a peripheral lymphadenopathy whose immunohistochemical characterization identifies the lymphatic dissemination of the disease. Gradually, the patient develops a severe anaemic state which requires several blood transfusions and surgical gastric resection to remove a large bleeding lesion of the antral region. The histopathological analysis of the specimen confirms the metastatic origin from MCC, but the primitive lesion remains unknown.

DISCUSSION

Since this clinical situation is very rare, we conducted a review of the literature selecting the few cases reported, in order to evaluate the current knowledge on this topic. Metastatic involvement of the stomach from Merkel cell carcinoma is a rare presentation of this disease progression with a frequent delay in formulating the correct diagnosis and in further treatment which may be life-threatening for the patient. As regards the local treatment, there is no specific guideline, and the therapeutic indication should be tailored on the specific case.

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.

Multiple gastrointestinal metastases of Merkel cell carcinoma

Merkel cell carcinoma is an aggressive skin malignancy. Primary Merkel cell carcinomas are treated by wide radical excision with or without adjuvant radiotherapy, while benefits of adjuvant chemotherapy remain doubtful. There are only several cases of gastrointestinal metastases of Merkel cell carcinoma reported so far. We report a case of recurrent Merkel cell carcinoma with metastases to the stomach and the small intestines after wide excision of primary Merkel cell carcinoma.

Rapidly growing gastric metastasis of Merkel cell carcinoma, an unusual cause of melena

Merkel cell carcinoma (MCC) is an uncommon, highly aggressive neuroendocrine skin carcinoma that has a tendency for local recurrence and metastatic disease. We report a rare case of recurrent melena in a 77-year-old Caucasian male. Three years earlier, the patient had undergone a radical resection of a para-umbilical MCC. A repeat esophagogastroduodenoscopy proved necessary to identify rapidly proliferating gastric metastasis of MCC as the cause of bleeding.

Merkel Cell Carcinoma With Gastric Metastasis and Review of Literature

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, highly aggressive cutaneous neoplasm, with a propensity for recurrence and metastasis. Very few cases of metastases to the gastrointestinal tract have been reported in the medical literature.

OBJECTIVES

The aim of this study was to report a case of MCC metastasizing to the stomach, its clinical presentation, and its management.

METHODS

A PubMed search was made using the following search terms: "Merkel cell carcinoma," "gastric," and "metastasis."

RESULTS

The investigators report a case of MCC metastatic to the stomach presenting with melena, syncope, early satiety, increasing fatigue, and unintentional weight loss. The other known cases of gastrointestinal metastasis of MCC are summarized and critically reviewed.

CONCLUSIONS

Although MCC spreading to the stomach is exceedingly rare, because of MCC's high recurrence rate and metastatic potential, it should be considered in patients with histories of MCC presenting with recent weight loss, early satiety, and gastrointestinal bleeding.

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.

Merkel cell carcinoma metastatic to the small bowel mesentery

Merkel cell carcinoma (MCC) is an uncommon cutaneous malignant tumor that presents as a rapidly growing skin nodule on sun-exposed areas of the body. MCC is aggressive with regional nodal and distant metastases to the skin, lung, and bones. There have been no reports of metastatic MCC to the mesentery and 6 reports describing metastasis to the small intestine. We present a case of metastatic MCC to the mesentery with infiltration to the small bowel, 8 years after original tumor resection. This is the 5^th metastasis and it encased the small bowel resulting in a hair-pin loop contributing to the unusual clinical presentation. Although MCC metastatic to the bowel is uncommon, it is not rare. It is important to recognize the unusual manifestations of this disease as they are becoming more common in the future. Routine radiologic surveillance and thorough review of systems are important to patient follow-up.

Ileocaecal recurrence of Merkel cell carcinoma of the skin: a case report

Introduction

Merkel cell carcinoma is an uncommon skin malignancy that has a high propensity for metastatic spread. A systematic literature search identified 17 cases describing metastasis to the gastrointestinal tract, with 7 cases involving the small or large bowel. To the best of our knowledge, this is the only case described of Merkel cell carcinoma metastasising to the ileocaecal valve.

Case presentation

We present a 74-year-old Filipino woman diagnosed with Merkel cell carcinoma of the skin with regional node involvement. Following excision and radiotherapy, the tumour recurred with metastasis to the ileocaecal valve. The patient died 28 months after the initial diagnosis.

Conclusion

The prognosis of metastatic Merkel cell carcinoma is poor. Currently the optimal management for metastatic disease is unclear and lacks a firm evidence base due to the small number of cases reported.

Metastatic Merkel cell carcinoma in the rectum: report of a case

Merkel cell carcinoma is a rare, aggressive skin malignancy of neuroendocrine origin with predominant occurrence in the elderly males. Approximately 50 percent of patients with Merkel cell carcinoma develop distant metastasis at some point during the disease course; hence, Merkel cell carcinoma always has a poor prognosis. Distant metastasis has never been disclosed in the rectum to the best of our knowledge. We present a 76-year-old male with clinical manifestation of massive hematochezia and final diagnosis of metastatic Merkel cell carcinoma in the rectum. We conclude that radical resection of rectal metastatic Merkel cell carcinoma is important in the management strategy of a patient with recurrence and lymph node metastases.

Neuroendocrine (Merkel cell) carcinoma of the retroperitoneum with no identifiable primary site

BACKGROUND

Neuroendocrine carcinoma is an aggressive neoplasm that mainly affects elderly Caucasians and typically arises in sun-exposed areas of the skin. The disease is rather rare and only a relatively few cases present with no apparent primary lesion.

CASE PRESENTATION

We report a case of an 81-year-old Caucasian male with neuroendocrine carcinoma, which initially presented as a large retroperitoneal mass. Pathological and immunohistochemical analysis of the transabdominal CT-guided biopsy specimen revealed tissue consistent with neuroendocrine carcinoma. The patient underwent exploratory laparotomy and the mass was successfully excised along with an associated mesenteric lymph node.

DISCUSSION

There are currently two possible explanations for what occurred in our patient. First, the retroperitoneal mass could be a massively enlarged lymph node where precursor cells became neoplastic. This would be consistent with a presumptive diagnosis of primary nodal disease. Alternatively, an initial skin lesion could have spontaneously regressed and the retroperitoneal mass represents a single site of metastasis. Since Merkel cell precursors have never been identified within lymph nodes, the latter theory seems more befitting. Moreover, metastasis to the retroperitoneal lymph nodes has been reported as relatively common when compared to other sites such as liver, bone, brain and skin.

CONCLUSION

Wide local excision of the primary tumor is the surgical treatment of choice for localized disease. We propose that further studies are needed to elucidate the true efficacy of chemotherapy in conventional as well as unconventional patients with neuroendocrine carcinoma.

Pancreatic metastasis of Merkel cell carcinoma and concomitant insulinoma: case report and literature review

Background

Merkel cell carcinomas are rare neoplasm of neuroendocrine origin, usually observed in elderly people in areas with abundant sunlight, and predominantly located on the head and neck, extremities, and trunk. In many patients, a local recurrence after resection of the primary tumour and even distant metastases can be found.

Case presentation

We report an unusual occurrence of pancreatic metastases from a previously diagnosed Merkel cell carcinoma with the discovery of a concomitant insulinoma. An 82-year old lady suffered from recurrent attacks of hypoglycemia and presented with an abdominal mass, 2 years prior she had an excision done on her eyebrow that was reported as Merkel cell carcinoma. An extended distal pancreatectomy and splenectomy along with resection of the left flexure of the colon for her abdominal mass was carried out. Final histopathology of the mass was a poorly differentiated endocrine carcinoma in the pancreatic tail, in the peripancreatic tissue and in the surrounding soft tissue consistent with metastatic Merkel cell carcinoma in addition to an insulinoma of the pancreatic body.

Conclusion

This is the first documented case of a metastatic Merkel cell carcinoma and a concomitant insulinoma, suggesting either a mere coincidence or an unknown neuroendocrine tumor syndrome.