Enteroenteric intussusception caused by a small bowel metastatic cutaneous melanoma.

Unlike in children, intussusception is very rare in adults and accounts for only 1% of ileus in that population. While intussusception in children is most often idiopathic, in adults the cause of intussusception in most cases is tumor and most often metastatic adenocarcinoma. It is an extremely rare phenomenon for intestinal melanoma metastasis to be the cause of intussusception and has been described in the literature so far only in a limited number of case reports. 41-year-old female patient was admitted to the emergency department with a clinical picture of ileus. The patient had a melanoma excision on her back five years ago, for which chemotherapy and radiotherapy were carried out. An MSCT of the abdomen was performed, which indicated an obstructive ileus of the small intestine with a typical sign of intussusception (target sign). Upon explorative laparotomy enteroenteric intussusception was found with an invaginated segment of the ileum in a length of about 20 cm. When the intussuscepted segment was reduced, a black tumor the size of a plum was verified as a leading point. Histological analysis indicated metastatic cutaneous melanoma with foci of melanocytes underneath normal intestinal epithelium.