Merkel Cell Carcinoma With Gastric Metastasis and Review of Literature

Gastric Metastasis of Primary Neuroendocrine Tumor of Skin: Rare Tumor with Rare Presentation

Merkel cell carcinoma (MCC) is a rare primary neuroendocrine tumor of the skin. It has an aggressive biological behavior and shows early local and distant metastasis. Diagnosis of MCC is a challenge and requires confirmation by immunohistochemistry (IHC). However, metastasis of MCC to the stomach is extremely uncommon and is rarely reported in the literature. We hereby describe a patient with gastric metastasis of MCC, who presented with black tarry stool and was finally diagnosed on the basis of clinical history, histology, and IHC.

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.

Partial Gastric Resection for Symptomatic Anemia following Diagnosis of Merkel Cell Carcinoma (MCC) of the Skin with Gastric Metastasis

Merkel Cell Carcinoma (MCC) is a rare dermatologic malignancy with significant morbidity and mortality associated with metastatic disease. In this case, we discuss and extremely rare presentation of MCC with metastasis to the stomach in a patient that presented with profound anemia. Unfortunately, mortality following diagnosis of MCC with gastric metastasis approaches 67% at 4 months based on available published reports. Due to its rarity and high rate of mortality, there is a lack of available research and literature to help guide treatment of this rare presentation of MCC. This case report presents a positive outcome associated with a partial gastrectomy for the treatment of symptomatic MCC with gastric metastasis and continued survival with persistently stable hemoglobin at 12 months.

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.

A Rare Case of Metastatic Merkel Cell Carcinoma to the Stomach and Pancreas Presenting With Upper Gastrointestinal Bleeding and Obstructive Jaundice

Merkel cell carcinoma (MCC) is a rare and aggressive primary neuroendocrine tumor of the skin. Gastrointestinal (GI) metastasis in MCC is uncommon. We present a case of MCC with metastasis to the stomach, duodenum, and pancreas presenting with melena and obstructive jaundice. A large, bleeding metastatic mass was identified in the duodenum. Hemostasis was achieved with coil embolization. Endoscopic retrograde cholangiopancreatography with stenting of the common bile duct was performed to relieve the obstruction. Close surveillance with positron emission tomography/computed tomography scan and possible GI endoscopy should be performed in cases with distant metastasis to identify and treat early GI tract lesions.

Gastrointestinal involvement of primary skin diseases

Less is known about gastrointestinal (GI) involvement of primary skin diseases due to the difference in embryology, histology, microbiology and physiology between integument and alimentary tract. Oesophagus, following the oropharyngeal mucosa, is the most common GI segment affected by primary skin diseases, especially by eosinophilic oesophagitis, lichen planus and autoimmune bullous dermatoses like pemphigus vulgaris, mucosal membrane pemphigoid and epidermolysis bullosa acquisita. Eosinophilic oesophagitis is an emerging chronic atopic disease with oesophageal dysfunction as the typical presentation, and oesophageal narrowing, rings and stricture as late complications. Oesophageal lichen planus mainly involves the proximal to mid-oesophagus in elderly aged women with long-term oral mucosal lesions. In acute attack of pemphigus vulgaris, oesophageal involvement is not uncommon but often neglected and may cause sloughing oesophagitis (oesophagitis dissecans superficialis) with acute GI bleeding in rare cases. GI manifestation of hereditary bradykininergic angio-oedema with colicky acute abdomen mostly affects small intestine, usually in the absence of pruritus or urticaria, and is more severe and long-lasting than the acquired histaminergic form. Strong evidence supports association between inflammatory bowel disease, especially Crohn disease, and hidradenitis suppurativa/acne inversa. Patients with vitiligo need surveillance of autoimmune liver disease, autoimmune atrophic gastritis or coeliac disease when corresponding symptoms become suspect. Melanoma is the most common primary tumour metastatic to the GI tract, with small intestine predominantly targeted. Gastrointestinal involvement is not uncommon in disseminated mycosis fungoides. Extramammary Paget's disease is an intraepidermal adenocarcinoma of controversial origin, and a high association between the anogenital occurrence and colorectal adenocarcinoma has been reported. As GI tract is the largest organ system with multidimensional functions, dermatologists in daily practice should be aware of the gastrointestinal morbidities related to primary skin diseases for an early diagnosis and treatment.

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.