Two Cases of Diffuse Large B-Cell Lymphomas in the Cervical Lymph Nodes in Patients with Low-Grade Gastric Marginal Zone B-Cell Lymphoma (MALT Lymphoma)
In June 1997, a 52-year-old man without any medical history was referred to the department of gastroenterology because of gastric subepithelial tumor. Esophagogastroduodenoscopy (EGD) demonstrated 1 cm sized subepithelial tumor on the proximal antrum anterial wall (). Biopsies showed chronic gastritis only. He was admitted and diagnostic endoscopic mucosal resection was done (). The pathologic finding was diffuse aggregation of monomorphic lymphoid cells without any large cell or small cell component in the submucosal layer (). Immunohistochemical staining showed atypical lymphoid cells that were positive for pan B and lamda, but negative for pan T, bcl-2 and kappa. Ki-67 labeling index was 5%. These findings suggested his diagnosis was low-grade MALT lymphoma. Abdomen and pelvic computed tomography (CT), chest CT, bilateral bone marrow examination and F-18-fluorodeoxyglucose positron emission tomography (PET) were done and there were no involvement of disease. Although rapid urease test (RUT), serologic test for H. pylori, urea breath test (UBT) and H. pylori culture of gastric mucosa were all negative, he took triple regimen of H. pylori eradication including clarythromycin, amoxicillin, and proton-pump inhibitor (PPI) for 14 days. After the H. pylori eradication was completed, subtotal gastrectomy was done. In the pathologic review of surgical specimen, there were no residual tumor cells. We performed esophagogastroscopy, abdomen and pelvic CT and PET every 6 months for 2 years and then we performed the same examination every 12 months for 4 years. He had been followed without evidence of disease recurrence for 6 years, after which he stopped visiting our hospital. In May 2007, he was referred to our hospital again complaining of throat pain and neck mass. Neck CT showed multiple enlarged lymph nodes in bilateral cervical nodes (). The largest diameter of the involved lymph node was 6 cm. Excisional biopsy showed diffuse infiltration of large atypical lymphoid cells (), which were positive for CD 20, but not for CD 3, CD10, CD 56, ALK-1, or CD 21. Ki-67 labeling index was 90%. These findings suggested DLBCL. EGD and full staging evaluation showed no involvement of other site. He was diagnosed with stage IIA DLBCL and received three cycles of systemic chemotherapy including rituximab, cyclophospamide, doxorubicin, and vincristine (R-CHOP), followed by 3,600 cGy radiotherapy. He achieved and maintained complete remission until recent days.