colorectal lipoma
Introduction
Introduction to colorectal lipoma Lipoma is second only to polyps and adenomas in benign tumors of the large intestine, but the incidence of lipoma is rare. basic knowledge The proportion of illness: 0.004% Susceptible people: no specific people Mode of infection: non-infectious Complications: intestinal obstruction
Cause
Causes of colorectal lipoma
(1) Causes of the disease
The pathogenesis of colorectal lipoma is still unclear, and there is still no consensus, which may be related to the following factors:
1. Inflammation and irritation may play a major role.
2. Degenerative changes in connective tissue.
3. Perivascular fat infiltration of fiber trabeculae.
4. Local fat accumulation of lymph and local dysplasia caused by localized fat accumulation.
5. Connective tissue enters the metaplasia of adipose tissue.
6. Local adipose tissue dysplasia may be related to endocrine effects such as anterior pituitary and gonadotropin.
7. Local fat metabolism is incomplete.
(two) pathogenesis
Colorectal lipoma mostly occurs in the right colon, especially in the cecum. Its general shape is a yellow round lobulated mass, soft, microscopically mature fat cells, fibrous interstitial, inflammatory cells around the tumor tissue. Infiltration, a small number of lipomas can be associated with necrosis, ulcer formation and hemorrhage, cystic changes.
According to the location and growth pattern of lipoma, it is divided into 4 types:
1. Endoluminal type (submucosal type) The most common, accounting for about 90%, lipoma under the submucosal and muscular layer local growth, protruding in the intestinal lumen.
2. Extraluminal (subserosal) Lipomas are localized between the subserosal and muscular layers and generally protrude outside the intestinal lumen.
3. Inter-wall type (intermuscular type) The tumor is located in the muscular layer of the intestinal wall. Generally, it does not protrude into the intestinal cavity. The tumor is round or oval, and there is no clinical manifestation.
4. Mixed type can be divided into four types according to the location and distribution of lipoma: single, multiple, diffuse lipoma and submucosal adipose tissue infiltration, lipoma cancer is extremely rare.
Prevention
Colorectal lipoma prevention
Lipoma is rare because of malignant transformation, so there is no recurrence after surgery.
Complication
Colorectal lipoma complications Complications, intestinal obstruction, intussusception
1. When the tumor is large, it can cause intestinal obstruction and intussusception.
2. Individual patients may have anemia and weight loss.
Symptom
Symptoms of colorectal lipoma Common symptoms Blood in the stool, abdominal pain, bowel movements, habits, changes, urgency, rectal intussusception
Patients with colorectal lipoma have no obvious clinical manifestations. The severity of symptoms is related to the size of the tumor. When the diameter of the tumor is larger than 2cm, more than half of the patients have uncomfortable symptoms. Common symptoms are: abdominal pain, changes in bowel habits, bloody stools or mucus Blood, when the lesion is located in the rectum, may be accompanied by urgency and heavy weight. When the tumor is large, it may cause intestinal obstruction and intussusception. At this time, the mass may be touched in the abdomen, and a few submucosal lipomas may be disconnected due to part of the tumor. Falling into the intestine, patients can discharge yellow, agglomerate fat-like tissue from the anus, which is a characteristic clinical manifestation of colorectal lipoma. Patients rarely have systemic manifestations, and individual patients may have anemia and weight loss.
Examine
Examination of colorectal lipoma
The stool was mucus and bloody, and the occult blood test was positive.
1. X-ray examination using double irrigation of sputum irrigation or gas sputum, can also use water to enema, using water as a contrast agent, can make the density of lipoma and surrounding tissue more obvious, X-ray main performance:
(1) Low-density adipose tissue is visible in the plain film of the abdomen.
(2) sputum or sputum angiography, a round or oval filling defect with a smooth edge in the intestine.
(3) There is a morphological change in the compression of the tumor during the squeezing examination, and this phenomenon is not observed in other tumors.
2. Colonoscopy can directly observe the pelt or pedicle from the submucosal bulge, the surface is smooth or erosive hemispherical or lobulated yellow tumor, with biopsy forceps to compress the tumor, full of elasticity, pressure can make the depression, put it back Restoration, you can see the so-called pillow pad; use biopsy forceps to lift the tumor, the surface of the mucosa to produce a tent effect; repeated biopsy with biopsy forceps at the same site, can expose the fat tissue, the so-called "naked fat sign", get the organization It can be used for histological examination to confirm the diagnosis.
3. CT examination is a regular low-density block shadow, and the CT value is more than -80 ~ -120Hu injection of contrast agent, the image is more clear.
MRI examination MRI has better soft tissue resolution, distinguishes different tissue structures, has strong signal of heterogeneity to adipose tissue, high proton density of fat, and white strong MRI signal with T1 value of 60-80ms.
Diagnosis
Diagnosis and diagnosis of colorectal lipoma
The clinical manifestations of colorectal lipoma are mostly non-specific, and the clinical diagnosis is quite difficult. Domestic literature reports that only 3 of 30 patients have a clear diagnosis before surgery, and the appearance and symptoms of this disease are quite similar to precancerous or malignant lesions. To have a high degree of understanding, clinical symptoms such as abdominal pain, stool abnormalities and blood in the stool must be used for laboratory and other auxiliary examinations in order to confirm the diagnosis in time.
1. Clinical manifestations.
2. Laboratory and other auxiliary inspections.
Colorectal lipoma should be differentiated from colorectal polyps and adenomas, colorectal cancer, large intestine balloon disease, leiomyomas and neurofibroma. There are many specific symptoms in clinical manifestations, but according to auxiliary examinations, such as X-ray, CT, Colonoscopy and other general identification is not difficult, especially colonoscopy biopsy can directly provide pathological basis, diagnosis of colorectal lipoma should pay attention to some patients may be associated with malignant tumors of the digestive tract, 1 case of 30 cases of colorectal lipoma reported in China Concomitant colorectal adenocarcinoma, and foreign literature reported that colorectal lipoma associated with gastrointestinal malignant tumors up to 30%.
