Primary gastrointestinal lymphomas are one of the most common extranodal variants of non-Hodgkin lymphomas . in the last two decades, there has been a clear tendency towards a widespread increase in the incidence of these tumors. Among all malignant tumors of the gastrointestinal tract, primary non-Hodgkin lymphomas comprise from 1 to 10%. The prognosis is favorable and depends on the primary location of the tumor: 10-year survival with lesions of the stomach is 51%, of the small intestine – 54% and with a tumor of the colon – 35%. Various sections of the digestive tube are involved in the process unequally often: the stomach – in 55-70%, the small intestine – in 20-35%, the large intestine – in 5-10%. The rarest are considered primary non-Hodgkin ‘s lymphomas of the esophagus. Primary gastrointestinal lymphomas are represented by a heterogeneous group of tumors. A variety of morphological variants of non-Hodgkin digestive tube lymphomas explains the variability of clinical manifestations and therapeutic approaches. In general, tumors do not have pathognomonic clinical signs; the symptoms of the disease are caused by the location of the main tumor node and are similar to the clinical signs of tumors of any histogenesis of this localization. Common distinguishing features of gastrointestinal lymphomas : a plurality of lesions within the digestive tube, a tendency to regional lymphogenous dissemination and a high incidence of formidable, often fatal complications (bleeding, perforation, intestinal obstruction – 20%). Determining the prevalence of the process is carried out in accordance with the classification, which takes into account all the clinical features of non-Hodgkin lymphomas of the gastrointestinal tract, approved in 1993 in Lugano. In the plan of examination of patients to the generally accepted diagnostic measures must necessarily be added: fibrolaryngoscopy and the study of all sections of the digestive tract. The most common variant of gastric lymphoma is MALT lymphoma . A characteristic feature of MALTom is their antigenic dependence on infection of the gastric mucosa Helicobacter pylori . It is known that normally there is no lymphoid tissue in the gastric mucosa. It is believed that its appearance is pathognomonic for H. pylori infection. Currently, experience is being gained using antibacterial anti-Helicobacter therapy ( omeprazole , clarithromycin , amoxicillin) for the treatment of stage I MALTOM of the stomach (low grade): the possibility of achieving complete remission has been ascertained in more than 2/3 of patients. Details of antibiotic therapy are being specified. The main goal of this effect is the eradication of H. pilori . The antitumor effect occurs gradually after the eradication of H. pilori , but the timing varies widely – from 3 to 18 months. The management of patients in this category remains a subject of scientific research. Treatment of local stages (I-II) of other morphological variants of primary non-Hodgkin lymphomas of the gastrointestinal tract begins with neoadjuvant chemotherapy: for aggressive tumors, CHOP, CHOEP, R-CHOEP regimens are used; with indolent lymphomas – chlorambucil , COP, CVP and in combination with MabThera . With an effectiveness of 2-3 courses, treatment is continued until complete remission, in the absence of effect, radical surgery is performed. Radical operations can be performed in the vast majority of patients (> 70%). In the postoperative period, adjuvant chemotherapy (3-4 cycles) is carried out in accordance with the morphological variant of the tumor. The result of this therapeutic approach is good long-term results: 10-year survival exceeds 70%, and 15-year survival is 69%. Such results could convince of the advisability of using only surgical treatment, if not for changes in the quality of life of patients after radical surgical interventions (in particular, after gastrectomy , hemicolectomy ). This is precisely what caused the current tendency to expand the use of neoadjuvant chemotherapy. The use of radiation therapy in the postoperative period, on the one hand, does not have an additional effect, on the other hand, it worsens the quality of life due to the development of radiation reactions from the abdominal organs. This explains the unpopularity of adjuvant radiation therapy. However, radiation exposure is promising as induction therapy in clinical situations when, for one reason or another, the drug or surgical method cannot be used. The total focal dose to the lesion is 32-36 Gy. A special clinical variant of non-Hodgkin lymphoma of the small intestine is IPSID. Previously , the terms “heavy alpha chain disease” or “Mediterranean lymphoma ” were used to refer to this lymphoma . The leading clinical symptom of the disease is malabsorption in the small intestine, which leads to sharp persistent weight loss, a significant deterioration in general condition and low tolerance to standard chemotherapy. The disease occurs mainly in the countries of the Middle East, northern Africa, Central America, affecting more often men aged 20-30 years. Tumor infiltration spreads throughout the small intestine with maximum damage to the duodenum and ileum. The pathogenesis remains unknown; it is assumed that the basis is the hyperproliferation of heavy chains of immunoglobulin A. The prognosis is poor, 5-year survival does not exceed 20%. Radiation therapy is ineffective. Surgical treatment is also not successful due to the extent of intestinal lesions. The use of chemotherapy (regimens used for both indolent and aggressive non-Hodgkin lymphomas ) is not very effective . The use of antibacterial drugs of the tetracycline group seems promising; however, the rarity of the pathology and little international experience do not allow us to recommend the developed treatment regimen. Primary non – Hodgkin lymphoma of the rectum is found with the least frequency . Tumors are usually represented by aggressive B-cell lymphomas . Combined treatment: intensive chemotherapy in combination with local radiation therapy (30-40 Gy per tumor site in a daily dose of 1.5-2.0 Gy). Surgical treatment does not improve results. Generalization of the process is the main type of progression (> 75%), develops mainly in the first 2-3 years after local methods of exposure and requires treatment in accordance with the principles of treatment of common non-Hodgkin’s lymphomas .