A Rare Presentation of Diffuse Large B-Cell Lymphoma as a Gastric Outlet Obstruction With Complete Resolution After Chemotherapy.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL), accounting for approximately one-third of all cases. We report a case of DLBCL presenting as gastric outlet obstruction (GOO) with complete resolution of obstruction after chemotherapy without any surgical intervention. A 58-year-old man presented with an inability to tolerate oral intake, bilious vomiting, abdominal discomfort, and unintentional weight loss. Computed tomography (CT) of the abdomen and pelvis revealed large infiltrating retroperitoneal and mesenteric masses with extensive adenopathy. Conservative management of GOO was initiated, including gastric decompression using a nasogastric tube and intravenous fluid hydration. A para-aortic lymph node biopsy confirmed the diagnosis of DLBCL. Following the first cycle of chemotherapy, the patient showed remarkable improvement. A repeat CT scan of the abdomen demonstrated complete resolution of GOO. Gastric outlet obstruction secondary to DLBCL is a rare complication. Complete resolution of GOO with radiological evidence following chemotherapy alone, without surgical intervention, is rarely reported.