Mesenteric cyst

A mesenteric cyst is a cyst in the mesenterium, and is one of the rarest abdominal tumors, with approximately 823 cases reported since 1507. The incidence is between 1 per 100,000 to 1 per 250,000 hospital admissions.
Tillaux's triad named after the French surgeon Paul Jules Tillaux can be seen in cases of mesenteric cyst. It consists of the following signs:

a fluctuating swelling near the umbilicus
freely mobile in the direction perpendicular to the attachment of mesentery
on percussion: zone of resonance—i.e., band of bowel resonance and dull note behind due to fluid inside the cyst

It is basically of two types:

Chylolymphatic, the most common type: thin wall, lined by flat endothelium, clear chylous fluid present, separate blood vessels
Enterogenous: thick wall, lined by columnar, mucinous fluid present common blood supply

Treatments:

Chylolymphatic cyst: Enucleation
Enterogenous cyst: Excision of cyst along with resection and anastomosis of part of bowel that shares common blood supply with the cyst