A rare but interesting case of small intestinal tumor diagnosed by transrectal EUS-FNA (with video)

A 46-year-old woman was admitted to the gastroenterology department with 6 months of intermittent abdominal distension. The enhanced CT of the abdomen revealed multiple soft tissue masses in the small intestine with slight enhancement in arterial phase, accompanied by multiple enlarged retroperitoneal lymph nodes and extensive thickening of the mesentery [Figure 1]. Double balloon enteroscopy showed multiple submucosal lesions of varying sizes with depressions and erosions on the surface [Figure 2], and biopsy indicated chronic inflammation.Figure 1: Abdominal contrast-enhanced CT shows multiple soft tissue density lesions in the small intestine.Figure 2: Endoscopic image of the submucosal lesions in the small intestine.Because malignant tumors could not be ruled out, transrectal EUS-FNA was performed. EUS revealed multiple space-occupying lesions in the small intestine, moving with intestinal peristalsis. The peristalsis was weakened after intramuscular injection of 10 mg raceanisodamine hydrochloride, and then EUS-guided fine-needle aspiration was performed [Figure 3; Video 1]. Biopsies showed no significant pathological mitotic figure. Immunohistochemistry revealed that S-100 [Figure 4] was positive, whereas c-kit, SMA, CD34, DOG-1, and Calretinin were negative. Finally, the pathological diagnosis was neurofibroma. {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 1","caption":"EUS-guided fine-needle tissue acquisition from the detected submucosal lesions.","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_wu9g565g"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Figure 3: Endoscopic ultrasonography-guided fine-needle tissue acquisition from the detected submucosal lesions.Figure 4: Immunohistochemistry revealed that S-100 was positive.Because the tumor range is too large, accompanied by multiple enlarged lymph nodes, it cannot be completely removed. Therefore, the patient received symptomatic treatment. After the symptoms improved, she chose to continue follow-up due to concerns about the risk of surgery. In this very rare case of multiple neurofibromas of the small intestine, EUS-FNA plays a key role in achieving the pathological diagnosis. As we know, this is the first report of small intestinal neurofibroma confirmed by transrectal EUS-FNA. Meanwhile, clinicians need to be aware that neurofibroma is a differential diagnosis of multiple tumors of the small intestine.