OVERVIEW
Malignant lymphoma is a malignant tumor originating from lymphatic reticular tissue. Malignant lymphoma of the colon has an insidious onset, lacks specificity in the early stage, and often has a poor prognosis due to delayed diagnosis and treatment. It occurs in the terminal ileum and cecum, which are rich in lymphoid tissue, followed by the right half of the colon. Distribution characteristics can be limited, but generally more extensive than cancer. It is commonly non-Hodgkin’s lymphoma (NHL). It is a rare tumor of the gastrointestinal tract, accounting for 0.2% to 1.2% of colorectal malignancies.
Etiology
The etiology of malignant lymphoma of the colon is unknown and may be related to radiation, chemical carcinogenesis, toxins, and other factors.
1.Virus
EBV infection, resulting in immune function suppression, activation of oncogenes and malignant proliferation of B lymphocytes.
2. Immunosuppression
There is a correlation between the occurrence of lymphoma and immunosuppression. Immunosuppressive drugs also have an effect on the occurrence of lymphoma.
3.Environmental factors
Insecticides, pesticides, drugs, paints, atomic bomb radiation, radiation and chemotherapy, and congenital immunodeficiency diseases can lead to a higher incidence of lymphoma than the normal population.
Symptoms
Common clinical symptoms include nausea, vomiting, weight loss, abdominal pain, abdominal mass, change of bowel habit, blood in stool, intestinal obstruction, intussusception, acute peritonitis due to intestinal perforation. A small number of patients delay treatment due to early symptoms are not obvious. Clinically, it can be divided into three types:
1. Diffuse type
Infiltration is the main cause, the intestinal wall is diffusely thickened and hardened, the lesion intestinal segment loses luster, the intestinal lumen is narrowed, peristalsis disappears, thickened folds can be seen in the mucosa, and diffuse nodular changes can also be seen, with surface erosion or superficial ulceration, similar to infiltrating carcinoma, with a wide range of involvement.
2. Polyp type
The mass is broad-based, with smooth surface or nodular polypoid mass, or multiple hemispherical polyps, similar to benign lymphoid polyposis, with smooth surface, white color, thickening of local infiltration, disappearance of semilunar folds of the colonic pouch, local stiffness, and disappearance of peristalsis.
3. Ulcerative type
May be malignant ulcer characteristics, can also be manifested as benign ulcers, ulcers flat and superficial, surface white moss, flat circumferential embankment and so on. There is a kind of extra-intestinal mass type, which grows from the inside to the outside of the intestinal lumen, and the mass can compress the intestinal lumen to make it narrow, and the mucosal surface is normal.
Examination
The main method of diagnosing the disease is fiberoptic colonoscopy, which has a high positive rate. In endoscopic highly suspected malignant lesions, biopsy pathology sometimes only inflammatory cell infiltration, no tumor cells are seen. This may be related to factors such as shallow sampling, too small tissue, and extrusion during tissue clamping. Malignant lymphoma of the colon has certain characteristics in histology, and the submucosal tissue should be clamped in addition to mucosal sampling when taking biopsies.
Diagnosis
The diagnosis of malignant lymphoma of the large intestine mainly relies on fiberoptic colonoscopy.
The disease should be differentiated from colorectal cancer, which is similar in terms of history and clinical presentation, and often relies on biopsy to confirm the diagnosis when it cannot be differentiated by fiberoptic colonoscopy.
Treatment
A comprehensive treatment regimen based on surgery and systemic chemotherapy is appropriate for malignant lymphoma of the colon. Principles of the comprehensive treatment program:
1. systemic combined chemotherapy after radical colon or tumor resection, plus early multidrug chemotherapy (chemotherapy).
2. For extensive lesions, systemic chemotherapy is performed after palliative colon tumor resection. Commonly used chemotherapy programs include: CHOP (cyclophosphamide, adriamycin, vincristine, prednisone), R-CHOP (Merovia + CHOP), MACOP and other programs.
3. Lymphoma has high sensitivity to radiation therapy and is suitable for patients with limited lesions and regional lymph nodes. Radiation therapy is limited by the complications after radiation therapy to the small intestine and colon, and is therefore suitable for use in patients with limited lesions.