Umbilical nodule, a rare presentation of primary cutaneous endometriosis: Case report and literature review.

Umbilical endometriosis or Villar's nodule is defined as the presence of endometrial tissue within the umbilicus and represent 0.5%-1% cases of endometriosis ectopia. It is classified as primary or secondary based on the surgical history.

Jejunojejunal intussusception induced by a gastrointestinal stromal tumor: a case report and literature review.

Intussusception is defined as the invagination of a proximal segment of the bowel into the adjoining or distal segment. In most adults with intussusception, there is a demonstrable lead point with a definite pathologic abnormality. The clinical features of intussusception include chronic intermittent abdominal pain, nausea and vomiting, constipation, and a palpable abdominal mass.