Ileal Melanoma, A Rare Cause of Small Bowel Obstruction: Report of a Case, and Short Literature Review

Abstract

Background: Malignant melanoma frequently spreads to the gastrointestinal tract, with 60% of patients with advanced metastatic disease showing digestive involvement; however, primary MM of the small intestine is a controversial diagnosis. In fact, whether these lesions arise as true small bowel primary neoplasms or represent metastases from unidentified cutaneous melanomas remains debatable. The most common complications are intestinal obstruction, massive gastrointestinal bleeding, and perforation. Objective & Methods: We report a case of a 64-year-old patient, with an unremarkable medical history, in which a late diagnosis of primary ileal malignant melanoma in the setting of an emergency laparotomy due to small bowel obstruction, and where PET-scan showed costal metastasis. Therefore, we provide a narrative review of the scientific literature about this topic. Results: 36 cases of primary small bowel melanoma, included that in the present study, were found through our search in the scientific literature. Conclusion: Primary small bowel MM appears to be an extremely rare entity which clinicians should be more aware of, in order to plan better a correct strategy of early diagnosis and appropriate treatment.

A Survival Analysis of Chinese Patients with Gastrointestinal Mucosal Melanomas: A Single-Centre Retrospective Study

“…The condition of the primary or metastatic tumor and tumor location were found to be the independent factors that affected the prognosis of patients with gastrointestinal mucosal melanomas. With respect to the condition of the primary or metastatic tumor, another study showed that the prognosis was worse for primary intestinal melanomas, which tend to grow faster and more aggressively [14,15]. We drew a similar conclusion in this study.…”

Multiple gastrointestinal melanoma causing small bowel intussusception

“…Noncutaneous melanoma occurs very rarely. Cutaneous melanoma is commonly seen with metastasis to the GI tract, due to its rich vascular supply [1,7]. It contributes to 50% to 70% of small bowel secondary malignancy [3].…”

“…It was postulated that neural crest cells migrate from the umbilical mesenteric canal into the GI tract, which later differentiate into APUD cells. These cells undergo neoplastic transformation to form melanoma which may explain the commonest site of GI melanoma being at ileum, the distal end of umbilical mesenteric canal [1,3,4,6].…”

“…Malignant melanoma is a common malignancy of the skin. It frequently metastasizes the gastrointestinal (GI) tract, with up to 60% of cases presented as advanced metastatic melanoma [1,2]. Primary malignant melanoma of small bowel is a rare clinical entity.…”

“…Intussusception from melanoma as the pathological lead point poses a challenge to diagnose, especially when it is an uncomplicated, asymptomatic case [5]. The inciden-tal finding on imaging would often require surgical resection to confirm the diagnosis of intestinal melanoma [1,5]. GI melanoma, likewise any mucosal melanoma, are more aggressive than cutaneous melanoma with a median survival of about 4 to 6 months and a 5-year overall survival rate of less than 10% [6].…”