Invasive inflammatory fibroid polyp concomitant with Gastritis cystica polyposa and Inverted hyperplastic polyp of the stomach: a case report and literature review

Abstract

Background Inflammatory fibrous polyp (IFP) is a distinct fibroblastic neoplasm with a predilection for the stomach and ileum. It contains prominent inflammatory infiltration, with a particularly eosinophils. Platelet-derived growth factor receptor alpha (PDGFRA) mutations are postulated as the pathogenesis of IFP. IFPs have been widely considered as benign tumors without malignant biological behaviors. However, rare invasive cases have been reported. Case presentation A 75-year-old woman presented with unexplained hematemesis, dizziness, and weakness for 3h. Physical examination revealed upper abdominal tenderness on palpation. Contrast-enhanced computed tomography revealed a 6 cm nodule with a high-density shadow and ring enhancement with well-defined borders in the gastric body. Surgical excision was performed, and subsequent histopathological examination and immunohistochemical analyses confirmed the dignosis of gastric infiltrative IFP presenting along with gastritis cystica polyposa (GCP) and inverted hyperplastic polyp (IHP). The patient was positive for CD34 and PDGFRA expression, but PDGFRA exon 12, 14, and 18 mutations were not identified. There was no evidence of recurrence within the 4 years of surgery. Conclusions To our knowledge, this is the second case of an IFP invading gastric’s serous layer and the first case of an IFP presenting with both GCP and IHP. Meanwhile, we speculate that the growth of an IFP leads to the formation of GCP and IHP. While an IFP is benign in most cases, it can be invasive in rare cases. It may show local recurrence with inadequate excision. We expect to help pathologists have a comprehensive understanding of the rare biological behavior, and to help surgeons achieve better clinical management through providing the case and literature review.