helful link with many resources on mesenteric cancer, epidimeology, and treatment

https://emedicine.medscape.com/article/191675-overview#a11

Tumors originating in the abdomen or elsewhere in the body that can disseminate to the mesentery. The origin is the small bowel mesentery which is a broad, fan-shaped fold of peritoneum that suspends the loops of the small intestine from the posterior abdominal wall. The two layers of peritoneal reflection forming the mesentery contain a variable amount of fat through which run the major arteries, veins, and lymphatics of the small intestine. Its root, a bare area that is contiguous with the pararenal spaces, extends diagonally from its origin at the ligament of Treitz inferiorly and to the right toward the ileocecal valve and cause the tumour. Differential diagnosis can be done using CT and precise diagnostic is done using SPECT. The treatment is surgery or using nuclear radiation therapy.

Mesenteric tumors are uncommon lesions that are generally considered inclusive of similar lesions of the omentum. Primarily anecdotal references to this class of tumors have been made since the beginning of the 20th century. In 1936, Hart provided the earliest clear description of solid mesenteric tumors. As experience has accumulated in treating these lesions, a more complete picture of the various disease types that manifest as mesenteric masses has emerged.

Mesenteric tumors may be cystic or solid, and they may demonstrate malignant or benign clinical behavior. Although uncommon, they are encountered in all age groups from infancy to the very elderly. These tumors should be considered as an explanation for a palpable abdominal mass, but they are most commonly brought into the differential diagnosis of abdominal pathology once a suggestive radiologic study or an abdominal operation has been performed. An increased awareness of neoplastic and nonneoplastic processes that result in mesenteric masses aids the clinician in recognizing these diseases.

https://emedicine.medscape.com/article/191675-overview

Mesenteric tumors may be cystic or solid, and they may demonstrate malignant or benign clinical behavior. ... When this condition affects the lymph nodes in the membrane that connects your intestines to the abdominal wall, called mesenteric lymph node inflammation.