Non-operative Management of Spontaneous Gastropleural Fistula Caused by Primary Gastric Diffuse Large B-cell Lymphoma.

We herein report a 79-year-old man diagnosed with primary gastric diffuse large B-cell lymphoma (DLBCL) with gastropleural fistula (GPF), successfully treated by chemotherapy without surgery. If primary gastric DLBCL perforates during chemotherapy, surgery is often warranted. Our patient's computed tomography findings showed loculated pleural effusion with air foci in the left lower lobe, suggesting GPF. After six cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy, the fistula fully closed, and complete remission was achieved. In conclusion, while gastric DLBCL can exhibit spontaneous GPF, it can be treated with chemotherapy alone, which was well-tolerated in our patient.