Black lump in anus

Introduction Anal canal malignant melanoma prolapse symptoms: black masses in the anus are prolapsed, early in the small, can be self-returned, and later increased, need to be returned by hand. Malignant melanoma occurs in the skin and eyes, and the anal canal is the third. It is generally believed that the tumor comes from the melanocytes of the junctional sputum. Most of them can produce melanin, and a few can not produce it, but the cancer cells still have a dopa-negative reaction. The prognosis is basically the same. The tumor grows rapidly, has a high degree of malignancy, early metastasis, and has a very poor prognosis.

Cause

Pathogenesis:

The disease is derived from the malignant transformation of melanocytes. Melanocytes or their mother cells are derived from ectodermal neural crest cells that migrate to the skin, eye, mucosal surface, and nervous system during embryonic development. Under the influence of certain factors, such as hormonal metabolic disorders, chemical stimuli and high-energy radiation damage, melanocytes are hyperproliferated and malignant. Some people think that the anorectal junction is a stratified squamous epithelium, a large number of melanocytes are gathered, which is the histological basis of anorectal melanoma. Therefore, at present, it is considered that the resident malignant melanoma is primary, but it is primary or secondary to rectal malignant melanoma. There are still differences. Most people think that rectal malignant melanoma is a malignant melanocyte after the malignant transformation of the anal canal. The result of the upward expansion should be considered a transfer. The characteristics under the microscope are mainly: the tumor cells are similar to the sputum cells, which are polygonal, fusiform or polygonal, with large nuclei, deformities and vesicles, and the nucleoli are distinct. The phalanx is somewhat indeterminate, and the cytoplasm is generally less. Most of the different melanin particles can be found.

Long-term metastasis can occur in the early stage of the disease, and blood transfer is the main mode of metastasis, but also lymphatic metastasis. Multi-directional transfer of organs from distant parts.

an examination

Related inspection

Anal examination of anus

Clinical examination:

Prolapse symptoms

There is a black mass in the anus, which is small in the early stage. It can be reimbursed by itself and will be enlarged later.

2. Blood in the stool

The tumor has a low position and is susceptible to bleeding due to fecal friction or trauma, mostly blood. Or there is a black spill, stench.

3. Anorectal stimulation symptoms

As the tumor protrudes into the rectum of the rectum, stimulating the receptors in the rectal wall, the patient often feels anal discomfort discomfort, changes in bowel habits, constipation and diarrhea alternate.

4. Lump

Generally 3 to 6 cm, near the tooth line, it is nodular, polypoid, hard. Most are purple-black or brown-black.

5. Anal pain

It is a common symptom of malignant melanoma. Anal pain can occur when a tumor collapses, infects, or invades tissue surrounding the anus.

Rectal melanoma is generally seen in the eyes of 80% or less. It is common to have melanoma with little or no melanin, so it is often misdiagnosed. The final diagnosis often requires pathological examination. Because the skin around the anus is often bordered, the disease should be highly suspected when the volume of the sputum is greater than 0.5cm. For no pigmented tumors (1/3), it can also be confirmed by means of Massobn-Fonlana melanin silver staining or dopa staining and tyrosinase reaction.

Differential diagnosis

Differential diagnosis of black mass loss in the anus:

1, prolapsed hemorrhoids: prolapsed hemorrhoids is a pathological hypertrophy, displacement of the anal cushion, often accompanied by bleeding, pain.

2, thrombotic external hemorrhoids: thrombotic external hemorrhoids (external hemorrhiod) thrombotic external hemorrhoids is a clinically frequently-occurring disease, often due to overeating spicy food, stools to the toilet, the perianal subcutaneous vein rupture, blood stasis under the skin. Clinically, the patient is conscious of anal swelling, pain and foreign body sensation as the main symptom. It can be seen that there are grape-like dark purple tumors under the perianal or anal canal, sometimes with mild erosion on the surface.

3, rectal cancer: rectal cancer (rectal cancer) is the common incidence of malignant tumors in the gastrointestinal tract after the stomach and esophageal cancer is the most common part of colorectal cancer (accounting for about 65%) most genetic patients are over 40 years old About 30% of men under the age of 30 are more likely to have a male to female ratio of 2-3:1. Rectal cancer is a lifestyle disease. At present, it has jumped to the second place in the cancer rankings, so diet and lifestyle are the root causes of cancer. Rectal cancer is usually mentioned together with colon cancer due to similar causes and symptoms.

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