Ascites as the initial characteristic manifestation in a patient with primary gastric CD8-positive diffuse large B-cell lymphoma.

CASE PRESENTATION: Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy and the most common type of non-Hodgkin's lymphomas, the stomach is the most common extranodal site. Gastric DLBCL is often characterized by epigastric pain and vomiting. We report a case of a 78-year-old female patient with gastric diffuse large B-cell lymphoma (DLBCL) with high CD8 level which was initially manifested with ascites of unknown origin. The patient was admitted with a chief complaint of abdominal distension and scanty urine over the last twenty days, while without anorexia and fatigue until 15 March. She had no history of viral hepatitis, tuberculosis, schistosomiasis.

RESULTS: Laboratory data revealed normal aminotransferases and bilirubin levels, but serum lactate dehydrogenase, CA125, ascitic fluid lactate dehydrogenase, ascitic fluid lymphocytes increased. The ascitic fluid was yellow-colored with 98.5% lymphocytes. Stool occult blood test was positive. Upper gastrointestinal endoscopy performed a few days later revealed multiple gastric crateriform ulcers, and Helicobacter pylori was detected in the biopsy specimen. Peripheral blood CD8+ was increased by 51%. Pathology test showed lymphocytes with atypical hyperplasia, and immunohistochemistry test resulted CD20+, CD10-, CD79α+, κ+, bcl-6+, Ki-67+ (approximately 95%), λ-, bcl-2-, CD3-, CD43-. Immunoglobulin gene (Ig) clonal rearrangement showed IgH: FR1 (+), FR2 (+), FR3(-), Igk: VJ(+), Vkde (+) in lymphoma tissue.

CONCLUSIONS: The features of histopathology and immunohistochemistry of the tissue confirmed diffuse large B-cell lymphoma (DLBL). The patient received an uncompleted CHOP program combined with H. pylori eradication. However, the patient deceased due to disease development sixteen days later after the diagnosis.