Plexiform angiomyxoid myofibroblastic tumor, also known as plexiform fibromyxoma, is a novel rare entity of gastric mesenchymal tumors, typical of gastric antrum, and commonly causing mucosal ulceration with upper gastrointestinal bleeding and anemia, and effectively treated by complete surgical resection usually accomplished by distal gastrectomy.
We report one recent patient from our center meeting clinical and histopathologic criteria compatible with plexiform fibromyxoma.
A 37-year-old male patient with no history of interest was admitted with upper gastrointestinal bleeding with hemodynamic instability. A total of three esophago-gastro-duodenoscopies were performed and we could observe a five centimeter-violaceous lesion with antral location. At first it seemed like a blood clot, but later it was checked a greater consistency which was different than a blood clot and more similar to an antral vascular neoformation (Fig. 1)
Abdominal ultrasonography and abdominal contrast-enhanced computed tomography reported an irregular rounded heterogeneous lesion in gastric antrum and acute bleeding areas suggestive of hematoma, with a size of 5.8×4×5cm. However they could not check an underlying lesion or associated thickened gastric wall. After a new episode of hemodynamic instability, the patient underwent emergency surgical intervention with an antrectomy (Fig. 2). Postoperative period was uneventful and the patient was discharged on postoperative day 9.
Histopathological examination revealed partial dense collagenous matrices and networks of fine capillary-caliber blood vessels. The tumor demonstrated lobular or fused nodular growth of spindle cells without atypical cytology, with abundant alcian blue-positive myxoid extracellular matrix. Hematoxylin and eosin staining showed lobulated or fused multinodular growth. Immunohistochemically it demonstrated an expression of muscle specific actin, desmin, and immunoexpression of CD10, and it was negative for CD31, CD34, VIII Factor, S100, Ckit, DOG1, HHV8, ALK, MDM2, CD23.
This pathological anatomy revealed a case of gastric plexiform fibromyxoma, an angio-myxoid plexiform myofibroblastic tumor which is a benign tumor that has recently been defined as a multinodular myxoid tumor with a peculiar plexiform growth pattern, myxoid stroma, prominent vasculature, and spindle cells with myofibroblastic differentiation.
This type of tumor was recently characterized by Takahashi et al.1 and Miettinen et al.,2 and 60 cases of plexiform fibromyxoma including the present case have been reported so far.3 According to previous reports, this tumor can occur at any age range, 7–75 years, typically middle age, and has a roughly equal gender distribution. The clinical presentation is generally similar to that of GISTs, with hematemesis being the most common symptom.4 In some rare cases, pyloric obstruction with weight loss may be noted. This tumor is predicted to exhibit benign biological behavior and there have been no reported cases of local recurrence or distant metastases after resection with a margin of normal tissue.
In conclusion, the current article reports a case of plexiform fibromyxoma, a rare mesenchymal gastric neoplasm that requires distinction from the others gastric mesenchymal tumors. Because of this, it is very important we know its symptoms, endoscopic and radiological images and its immunohistochemical in order to make an better diagnosis and treatment.
