Our patient is a female patient, 17-year-old. She had a history of persistent abdominal pain. During gastroscopy, a fundal submucosal tumor was detected. The patient was sent for EUS, and their EUS showed that it was a hypoechoic submucosal tumor, and it was arising from a third layer, which is the submucosa, and it was about 3.1 x 2.9 cm. The EUS FNA showed a picture suggestive of lipoma. These are the EUS pictures. On the left side, it looks like a well-circumscribed submucosal tumor that arises from the submucosa, and it is hypoechoic, and you can see on the right side, this is the FNA. However, the endoscopic picture was not consistent with lipoma, as you can see in the photo that it has a reddish surface, and it was hard on probing, and it showed no indentation on probing, which is negative pillow sign. So after discussing the treatment options with the patient, we decided to go for endoscopic resection. Before the procedure, the patient was given prophylactic antibiotics in the form of third-generation kefalosporins and metronidazole. The patient was intubated under general anesthesia. Here is the submucosal lesion. On retroflection of the scope, we can see the lesion with its reddish overlying mucosa. We start with a circular incision using hybrid knife, where you can cut, inject, and coagulate. Afterwards, we start with dissection around the lesion. You can dissect and inject in the same setting. During dissection, it was evident that part of the lesion was closely attached to the muscle. So we had to continue dissection through the MP layer. Now we had a complete perforation that was encountered. After almost near-complete dissection of the lesion, we used a snare for the final cut. And here is the excised lesion. Then we do hemostasis to the bed of the lesion using a coagulation grasper. Then we decided to close the defect using an indoloop and clips called purser string suture. The indoloop is anchored to the edges of the defect with indoclips and then we gently close the indoloop. And here we can see the defect is closed. Histopathology showed that intact gastric mucosa and the submucosa showed hypocellular bluish myxoid material with abundancy in fibrite bands. Another photo showing that the submucosal tumor was rich in blood vessels and that made the procedure a little bit bloody. Plexiform fibromyxoma was made as the final diagnosis according to the histopathology. Plexiform fibromyxoma is a very rare mesenchymal tumor. It was first reported in 2007. In literature only 121 cases were reported till now. Mainly they are located in the gastric antrum and less commonly in the body and then the fundus. Few cases were reported in the duodenum, jejunum, gallbladder and mediastinum. Regarding the clinical presentation it had a wide range of symptoms. It can be asymptomatic that is accidentally discovered during endoscopy. It can present with non-specific symptoms like vague abdominal pain, just discomfort or distention. It can also have complicated presentations and these are serious presentation like bleeding or obstruction. However, according to literature abdominal pain is the most common presentation and gastrointestinal bleeding is the most serious presentation and remember that it is a highly vascular tumor. Grossly it appears as lobulated white or grayish whitish mass. It has a gelatinous cut surface with mucinous fluid. It has a multinodular growth pattern and it is not capsulated. Microscopically you can see spindle cells arranged in the plexiform pattern and these are separated by material with intervening rich arborizing capillaries. Sometimes immunological staining may be required in cases of overlap with gastrointestinal stromal tumors. Plexiform fibromyxoma is of benign nature. Till now no metastasis or recurrence had been reported. Surgery is the mainstay of treatment. However, according to the available data and that benign nature more conservative approaches are required like the endoscopic resection. This is the six-month follow-up of the patient. Our conclusion is Plexiform Fibromyxoma is a rare gastrointestinal submucosal tumor with increasing awareness. It should be considered in our differential diagnoses of submucosal tumors. More conservative approaches are warranted due to its benign nature. Here we present a simple solution for facing difficult situation using the purse-string suture to close a full thickness defect.

abdominal pain

fundal submucosal tumor

EUS

endoscopic resection

plexiform fibromyxoma