A16-year-old mare pony was admitted to the University Veterinary Hospital, UniversitiPutra Malaysia with the complaint of chronic abdominal distention. At necropsy, there was a red–black colored segment ofnonmotile and severely edematous small intestine along with its hemorrhagicmesentery strangulated by a pedunculated, firm, gobloid whitish mass thatmeasured approximately 5 cm in diameter. The root of the pedicle was located onthe mesentery 1 cm away from the intestine. Metastasis was not observed. Detailedhistopathologic investigation revealed mature adipocytes with compact eccentricnuclei and abundant lipid-filled cytoplasm. In consideration of the macroscopicand histological findings, the tumor was classified as lipoma.
Keywords: Lipoma is a benign mesenchymal tumor derived from fatty tissue (adipocytes). Usuallylipoma found in old age horses (>10 years). Because lipomas are fat, thenthey can appears anywhere on the body. The most common lipomas are frequentlyfound on the surface of the skin (superficial).
Lipomas can also develop inother parts of the body like the gut. These tumor can arisefrom the mesentery, a thin sheet of tissue that wraps the intestine. Inpedunculated lipoma, as the tumor grows and increases in weight, it startforming a pedicle (stalk) causing it to hang from the mesentery. The tumor isthen said to be “pedunculated,” forming a stalk or pedicle thatsometimes wrap around the loop of the small intestine.Pedunculatedlipomas can run the risk of becoming strangulated (twisted) when the pediclewraps around the loop of the small intestine, compromising the blood supply;this causes cellular death and possibly infection as well as other problems.Contributing factors include the weight of the lipomas, its location, thelength of the pedicle and sufficient momentum resulting from movement of the horseor intestinal motility allowing the lipoma to wrap around the intestine. The resulting compression prevent the flow of ingesta,occlude the blood vessel and the affected horses begin to show signs of colic,and discomfort which can be severe.
The cause of lipomain horses is still unknown. Most literature connect causes of lipoma are due toexcessive fat consumption and obesity, but none of that is scientificallyproven. The horse’s body condition score has nothing to do with the possibilityof having a lipoma.
A fat horse may never develop a lipoma, and skinny horsesare affected as often as their fat pastels. The actual risk factor is unknown,except that the tumor becomes problematic only if it has developed a stalk, asituation not often seen in a young horse. Gelding and ponies are known to beat a greater risk of colic resulting from pedunculated lipomas than are otherhorses.Atnecropsy, a pedunculated tumor mass with its peduncle arising from the mesentery.Gross examination of the specimen showed that this encapsulated yellow-brownsoft mass that measured 5 × 5 × 4.5 cm was a lipoma. Mature adipose tissue wasconfirmed by histologic examination; neither increased mitotic activity norlipoblasts was found.
Histologicexamination demonstrates mature adipose tissue. Neither increased mitoticactivity nor lipoblasts was found.In general,soft tissue tumors (STTs) are masculine proliferation occurring in theextracellular tissue nonepithelial tissue, is not including viscera, lining thebrain, and the lymphoreticular system. Can arise in a place where alone,although approximately 40% occur in the lower extremities, especially the thigharea, 20% in upper extermity, 10% in the head and neck, and 30% in the body andretroperitoneum. The occurrence of a lipoma can also be caused by aninterruption fat metabolism. In lymphoma proliferation occurs bothhistologically and chemically, including fatty acid composition of normal fattissue.
Fat metabolism in lipoma in contrast to normal fat metabolism, althoughhistologically the cell picture the fat is the same. In lipomas foundlipoprotein lipase activity decreased. Lipoproteins lipase important for thetransformation of fat in the blood.
Therefore the fatty acids on lipoma morethan normal fat. This can happen when someone is on a diet, then a normal fatdepot becomes reduced, but fat on lipoma will not decrease even increase. Thisshows that lipoma fat is not a fat needed by the body. The tumor cells are thecells of the body that undergo transparmation and grow in a manner autonom getrid of normal cell growth control so that this cell is different from cell normal in shape and structure. In general, tumors begin to grow from one cellsomewhere (unicentric) or from some central (multilocular) at a time same. Aslong as the tumor growth is still limited to the basic organ, the tumor calledstill in the local phase. But if there is infiltration to the surroundingorgans, then the tumor has reached localized infective or local infiltrativephases.
This local spread called the dissemination of perkontinuitatum, becauseit is still associated with its parent cell. These tumor cells continue to growindefinitely, so the tumor is getting older large and urgent surrounding tissueso that it can clog the body channels and cause obstruction. When the enlargedlipoma will appear as a prominence that can hit the surrounding tissue.
Whenthis malignant tumor can spread to other body parts and generally fatal if leftuntreated for damaging the organ in question and causing dead.Rapid diagnosis iscritical to identify the source of colic before the intestine are compromised.However, diagnosis of a pedunculated lipoma can be difficult, especially ifthere are some substances that are able to bypass the narrowing and discomfortalternately ease and restore. The colic caused by a pedunculated lipoma willnot heal by treatment, walking with horses, or other treatments except forsurgical removal of the tumor.
If surgery is done long enough in the course ofcolic, the prognosis is good for full recovery. However, since lipomas appearto be most common in older horses, the horse may have other health problemsthat delay recovery.