Nodal and rectal melanosis

Introduction to knot and rectal melanosis Melanoslscoli (MC) refers to a mucosal pigmentation disorder in which macrophages in the lamina of the colorectal parenchyma contain 1ipofuscinlike substances. With the improvement of people's living standards, the incidence of rectal melanosis has increased. There are few domestic reports of the disease. The etiology and pathogenesis of colorectal melanosis are still unclear. Electrolyte disorders may occur in patients with this disease, and the incidence of colorectal cancer and colorectal adenomatous polyps is high in this patient. A few patients may also have pseudo-intestines. Narrow, and mistaken laparotomy. basic knowledge The proportion of sickness: 0.01% - 0.02% Susceptible people: no specific population Mode of infection: non-infectious Complications: intestinal obstruction, indigestion

Causes of knot and rectal melanosis

The cause of rectal melanoma is still unclear, but its incidence has increased in recent years, possibly with improved living standards, increased fat and protein intake, decreased cellulose intake, increased constipation, and pre-rectal Sudden, rectum in the rectum, slow colonic transmission function and difficulty in defecation, a large number of abuse of laxatives, especially sputum laxatives are the main cause of melanosis.

Knot, rectal melanosis prevention

Conclusions, rectal melanosis is a reversible disease that relieves constipation and causes difficulty in defecation. For example, eat more vegetables, fruits, and other foods with more fiber, drink more water, exercise more, reduce constipation or difficulty in defecation. For rectal protrusions, rectal intussusception, puborectalis syndrome, etc., such as rectocele repair, rectal stenting, partial puborectal muscle resection, To restore normal bowel movements and prevent the massive abuse of laxatives is an effective way to prevent melanosis.

Knot, rectal melanosis complications Complications, intestinal obstruction, indigestion

1. Intestinal obstruction.

2. Indigestion.

3. Electrolyte metabolism disorder.

Symptoms of colorectal and rectal melanosis Common symptoms Colonic blackness, bloating, appetite, abdominal discomfort, constipation

General view: mucous membranes have different degrees of pigmentation, lighter is similar to leopard skin, heavy is dark brown, vascular texture is unclear, pigmentation can occur in a certain segment of the large intestine or the whole colon, small intestine mucosa and anal above the ileocecal valve The skin below the tube-tooth line has no pigmentation. Under the light microscope, there are a large number of dense or scattered macrophages in the lamina propria, and the cell volume increases. In severe cases, the cytoplasm is filled with pigment particles, and the nucleus is covered and difficult to see. Pigment particles are also visible outside the macrophages. This phenomenon is more common in the intestinal mucosa with III degree pigmentation. In some patients, the pigment particles in the macrophages are scattered. This phenomenon is more common in the colorectal mucosa with a degree of expression. In patients with rectal melanosis, severe colorectal melanosis, macrophages and pigment granules containing granules can also be seen in mesenteric lymph. These pigment granules are positive for melanin staining (Fontana silver staining) and negative for iron reaction. Electron microscopic observation: The number and volume of macrophages in the lamina propria were significantly increased, and the cytoplasm contained a large amount of lipofuscin, which belongs to secondary lysozyme. There is also a large amount of lipofuscin deposition in the connective tissue around it, which may be caused by the disintegration of macrophages. Macrophage containing lipoflavin particles can also be seen in the vicinity of the unmyelinated nerve fibers of the intestinal plexus. Or diffuse pigment particles.

Examination of knot and rectal melanosis

1. Blood routine is generally normal, a small number of patients mainly have low sodium, low potassium, low calcium and other performance.

2. Endoscopy: See the mucosa of the large intestine with varying degrees of pigmentation, according to the depth of pigmentation is divided into III degrees:

I degree: light dark brown, similar to leopard skin, asymmetrical milky white spots on the lymphoid follicles, viscous mucosal vascular texture, lesions mostly invading the rectum or cecum, or on a certain part of the intestinal mucosa of the colon, affected colonic intestine The range is much less, and there are many boundaries between the pigmented intestinal mucosa and the non-pigmented intestinal mucosa.

II degree: dark brown, with a line of milky white mucous membrane between dark brown mucous membranes, more common in the left colon or a segment of the colonic mucosa, mucosal blood vessels are difficult to see, pigmented intestinal mucosa and non-pigmented intestinal mucosa The dividing line is clearer.

III degree: dark dark brown, there are fine milky white lines or spotted mucosa between dark dark brown mucosa, mucosal vascular texture is invisible, this performance is more common in the whole colon type, the lesion does not invade the ileal mucosa, and the ileocecal valve mucosa More than tired, the rectal dentate line below the anal canal skin without pigmentation, it is generally considered that colorectal melanosis pigmentation of the large intestine mucosa is more common in the cecum

Diagnosis and differentiation of knot and rectal melanosis

diagnosis

Mainly based on medical history and endoscopy, see the intestinal mucosa with varying degrees of pigmentation, as well as endoscopic biopsy lesions for pathological examination, see a large number of dense or scattered distribution in the lamina propria, cytoplasm contains pigment particles The macrophages can be used to determine the diagnosis.

Differential diagnosis

1. The disease should be differentiated from the "brown intestinal syndrome" of patients with steatorrhea. The patients with steatorrhea are pigmentation around the nucleus of intestinal smooth muscle cells, which are brown and have no pigmentation in the lamina propria of the intestinal mucosa.

2. Patients with colorectal melanosis should also be differentiated from hemorrhagic colitis and submucosal bleed hemorrhage. The latter two lesions are more limited, and the mucosa of the lesion is purple-red.

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