Abstract

Background: Plexiform fibromyxoma (PFM), also known as plexiform Angio myxoid myofibroblast tumour, is a rare benign mesenchymal neoplasm of the stomach. It typically arises from the gastric antrum and can mimic GIST both clinically and radiologically. Case Presentation: A 38Year/female with complaints of black coloured stool since last 20 days UGI Scopy - Stomach showed ulcero - proliferative lesion? Extrinsic infiltration at antral region. OGD Biopsy report- Chronic active gastritis with severe ulceration. No granuloma /dysplasia, Malignancy. CECT- demonstrated a lobulated submucosal homogenously enhancing soft tissue lesion in the Antro pyloric region, causing moderate compromise of the lumen. Findings are in favour of neoplastic Lesion. The patient underwent Distal Gastrectomy with Retro Colic Gastrojejunostomy. HPE - Neoplasm with spindle to stellate cells - Suggestive of mesenchymal Origin, involving wall of stomach IHC - Positive for smooth muscle actin (SMA) and CD10, and negative for ALK, CD34, SOX 10, S100, CK AE1/AE3, Beta catenin, DOG 1. Features are consistent with Plexiform Fibromyxoma. The postoperative course was uneventful. Conclusion: Plexiform fibromyxoma is a distinct benign gastric tumour that closely mimics GIST. Awareness of its characteristic histopathological and immunohistochemical features is essential for accurate diagnosis and to prevent unnecessary aggressive treatment.