Case Presentation: S.G. is a 51-year-old woman originally from Ethiopia without past medical history who presented with two weeks of abdominal distention, lower extremity swelling and 10 lbs of weight loss. On presentation, her exam was notable for decreased bibasilar breath sounds with dullness to percussion, no elevation in jugular venous pulse, abdominal distention without tenderness to palpation and positive shifting dullness, palpable 1-2 cm non-tender inguinal lymphadenopathy and 1+ pitting edema to the ankles. Labs on presentation were unremarkable. CT abdomen/pelvis was performed which revealed diffuse gastric wall thickening with peritoneal nodularity, retroperitoneal lymphadenopathy and large volume ascites, concerning for metastatic primary gastric neoplasm.
She underwent esophagogastroduodenoscopy which revealed diffusely congested, erythematous and friable gastric mucosa with decreased vascular pattern. Light microscopy of biopsy specimens revealed numerous microorganisms throughout the gastric mucosa, thought to be Helicobacter pylori, and preliminary pathology was suggestive but not definitive for marginal zone B cell (MALT) lymphoma. However, her presentation was thought to be more consistent with an aggressive subtype of lymphoma or another primary malignancy, therefore further workup was performed. She underwent large volume paracentesis and right-sided thoracentesis, both of which yielded negative cytology and flow cytometry. A PET-CT was then performed which showed intense FDG uptake that highlighted diffuse gastric thickening and FDG-avid adenopathy in the chest, abdomen, pelvis and thigh. She then underwent an excisional biopsy of left inguinal lymph node. Subsequently, pathology from the gastric and lymph node biopsies in addition to flow cytometry from the lymph node specimen revealed positive immunohistochemical staining for Helicobacter pylori as well as a dense lymphoid infiltrate composed of CD-20 positive B cells, most consistent with follicular lymphoma rather than MALT lymphoma. She has received six cycles of bendamustine–rituximab chemotherapy and is currently in complete remission.

Discussion: H. pylori is the most common chronic bacterial in the world. Rates of endemicity are higher in resource-poor regions. It is associated with development of gastric adenocarcinoma and MALT lymphoma, but its association with other malignancies is unknown. Follicular lymphoma is a heterogeneous group of non-Hodgkin lymphomas (NHL) derived from germinal B cells and is typically indolent. It is reasonable to consider watchful waiting for low grade/low stage follicular lymphoma, but if a patient develops symptoms, chemotherapy is warranted.

Conclusions: H. pylori infection is associated with gastric adenocarcinoma or MALT lymphoma, but may be associated with other lymphomas as well. Follicular lymphoma is typically indolent, therefore when a patient presents with a rapidly progressive clinical course it is important to consider the possibility of transformation to a more aggressive subtype of NHL.