Recurrent plexiform angiomyxoid myofibroblastic tumour (PAMT) of the stomach with aggressive behaviour

Pediatric Plexiform Fibromyxoma: A Case Report

The plexiform fibromyxoma is a rare mesenchymal tumor in adults that generally originates in the antrum of stomach, being its occurrence in pediatric patients exceptional. It was classified as a distinct entity by World Health Organization in 2010. No recurrences and metastases have been documented in many of the reported patients to date, being the surgical treatment curative. We report the case of a 3-month-old infant who presented to the emergency department with an episode of intestinal subocclusion requiring an emergent surgery. During the surgical intervention, a mass was identified in the jejunum, causing partial occlusion of its lumen. The surgical pathology report revealed an infiltrative tumor composed of spindle-shaped cells disposed in a stroma with a plexiform pattern alternating myxoid areas. These findings and the immunohistochemical characteristics of the neoplastic cells led to classify the tumor as a plexiform fibromyxoma. A description of the immunophenotype of this tumor is made and differential diagnosis with other gastrointestinal tumors is also discussed.

A case of asymptomatic gastric plexiform fibromyxoma followed up for 3 years

Plexiform fibromyxoma is a rare mesenchymal tumor identified in recent years and presents as a gastrointestinal submucosal tumor that is typically located in the gastric antrum. We report a case of gastric plexiform fibromyxoma in which the diagnosis was difficult despite repeated tissue sampling. Before visiting our hospital, the patient had been followed up for 3 years without a definitive diagnosis despite serial examinations, including computed tomography, endoscopy, endoscopic ultrasound, and endoscopic ultrasound-guided fine-needle aspiration. Endoscopic ultrasound-guided fine-needle aspiration was reperformed, and endoscopic submucosal dissection for deep biopsy was conducted for differential diagnosis of the tumor. However, histological analysis with immunostaining of tumor samples obtained using these techniques cannot provide a reliable diagnosis. Finally, the tumor was resected surgically because of its increasing size, and subsequent microscopic analysis revealed a multinodular plexiform growth pattern of spindle-like cells with myxoid stroma. Immunohistochemically, the tumor cells were positive for smooth muscle actin but negative for c-kit, CD34, and S100. Based on these findings, the patient was diagnosed with plexiform fibromyxoma. No evidence of residual or recurrent tumors was observed at 24 months postoperatively.

Endoscopic submucosal excavation for gastric plexiform fibromyxoma: A case report and systematic review of literature

Plexiform fibromyxoma (PF) is a rare mesenchymal tumor of which the pathogenesis and molecular changes are still unclear. Histologically, it is characterized by a cluster of bland spindle or ovoid cells growing in the mucoid or fibromyxoid stroma rich in small blood vessels. At present, surgical resection is the primary treatment for PF.