Peritoneal lymphomatosis as the only manifestation of diffuse B-cell large cell lymphoma: A clinical case

Non-Hodgkin's lymphoma can occur anywhere in the human body. A diffuse extensive peritoneal lesion is uncommon and rare. Diffuse large B-cell lymphoma is the most common histological type of extranodal lymphoma in peritoneal lymphomatosis. A case of isolated peritoneal lymphomatosis is presented. A 23-year-old female patient N. presented with decreased appetite, bloating, pain, and abdominal enlargement. The symptoms persisted for 4 months. Recently, she reported a fever (38.4°C), sweating at night, and decreased body weight. On physical examination, the abdomen was enlarged, tense on palpation, tender in the epigastrium, and dull to percussion in all parts. No signs of specific changes in peripheral lymph nodes were observed. Tachycardia was noted, and blood pressure was within normal range. Five weeks ago, a laparoscopy was performed, which revealed an extensive infiltrative lesion of the parietal and visceral peritoneum of the abdomen and pelvis and the greater omentum with the presence of mesenteric lymph nodes. A biopsy of the peritoneum and greater omentum was performed. Cytological examination of ascitic fluid showed a pattern of non-Hodgkin's lymphoma. Histological examination revealed diffuse large B-cell lymphoma with CD20+ expression. Positron-emission and X-ray computed tomography with 18-fluorodeoxyglucose (FDG) showed diffuse thickening of the parietal and visceral peritoneum, mesentery and omentum with subtotal filling of the abdominal and pelvic cavities with masses with increased radiopharmaceutical uptake. No FDG-active lesions were detected in the liver and spleen parenchyma. Diagnosis: diffuse large B-cell lymphoma, stage IVB; peritoneal lymphomatosis, IPI 3. Polychemotherapy was recommended according to the R-CHOP regimen. The patient refused the proposed treatment due to the change of domicile. Isolated peritoneal lymphomatosis is a rare manifestation of extranodal non-Hodgkin's lymphoma. There are no specific clinical symptoms. Positron emission and X-ray computed tomography with 18-FDG are an alternative method for diagnosing peritoneal lymphomatosis.