P1021 - Large Gastric Mass Found to Be a Rare Benign Tumor Called Inflammatory Fibroid Polyp

Fatema Najmi, ¹, Fleurette Chong, MS², Layth L. Saymeh, MD³, Mathew R. Fries, MD^4
1Trinity School of Medicine, Macon, GA; ²Trinity School of Medicine, Kathleen, GA; ³Houston Medical Center, Warner Robins, GA; ⁴Southeastern Pathology Associates, Warner Robins, GA

Introduction: A rare entity found mostly in the submucosa of the gastrointestinal tract, inflammatory fibroid polyps (IFP) can grow very large yet cause minimal symptoms and are known to make up only 0.1% of gastric polyps. We present a case on a removal of a 5 cm IFP causing minimal symptoms.

Case Description/Methods: A 71-year-old African American male with a past medical history of chronic lymphocytic leukemia presented with a long-standing history of microcytic anemia with a baseline hemoglobin of 4.5. The patient denied any symptoms of occult bleeding. EGD showed a pedunculated polyp in the antrum of the stomach. The polyp was removed via a hot snare and the specimen was sent to the pathology lab for further testing. The pathology report showed the polyp was a circumscribed mesenchymal tumor involving mucosa and submucosa, measuring 5 cm. It was composed of bland spindled cells with mixed inflammatory cell infiltrate, including eosinophils, lymphocytes, and plasma cells. Onion skin proliferation around vessels was also documented. The spindle cells were positive for immunohistochemical marker CD34, and negative for S100, CD117, desmin, pancytokeratin, and SOX-10. Molecular evaluation of the polyp detected a mutation in the PDGFRA (platelet-derived growth factor alpha). These findings are consistent with the diagnosis of inflammatory fibroid polyp.

Discussion: The cause of IFPs are largely unknown and most are asymptomatic. Larger polyps, however, can be associated with gastric outlet obstruction, intussusception, early satiety, or anemia. Our patient’s presentation was either asymptomatic or overshadowed by his diagnosis of chronic lymphocytic leukemia and long-standing microcytic anemia. Discovery of the gastric polyp was incidental while trying to locate a source of bleeding via upper endoscopy. There were several differentials to consider in addition to IFPs, such as GISTs, other spindle cell tumors, or inflammatory myofibroblastic tumors. However, these differentials were ruled out with immunohistochemical staining as well as clinical presentation. Treatment for IFPs has largely been surgical or by endoscopic resection, as there is a low rate of recurrence. One of our patient’s main medical problems continues to be microcytic anemia. Interestingly, there have been cases where anemia is largely resolved by the resection of an IFP. Our patient will have to be monitored to determine if his IFP played a role in his anemic condition.



Disclosures:


Fatema Najmi, ¹, Fleurette Chong, MS², Layth L. Saymeh, MD³, Mathew R. Fries, MD⁴. P1021 - Large Gastric Mass Found to Be a Rare Benign Tumor Called Inflammatory Fibroid Polyp, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.