A rare cause of small intestinal obstruction in children: a case report of calcifying fibrous tumor

Abstract Background Calcifying fibrous tumor (CFT) is a rare benign mesenchymal tumor. Primary small intestinal CFT causing intestinal obstruction in children is exceptionally rare. Preoperative diagnosis remains challenging due to its nonspecific clinical manifestations. Ultrasound holds potential advantages in pediatric abdominal imaging, though further studies are needed to validate its utility for rare entities like CFT. Case presentation A 3-year-old girl presented with progressive abdominal distension for 2 months, accompanied by occasional periumbilical restlessness (suggestive of mild discomfort). No bilious vomiting was noted, and bowel movements remained regular with normal consistency. High-frequency abdominal ultrasound revealed dilated small bowel loops, focal jejunal wall thickening (6 mm) with calcified foci and posterior acoustic shadowing, and punctate blood flow signals on color Doppler imaging, collectively indicating mechanical obstruction secondary to localized calcified wall thickening. CT confirmed small bowel dilation and high-density calcified lesions. Laparoscopy-confirmed obstructive jejunal stenosis further prompted mini-laparotomy with curative jejunal resection and primary anastomosis. Histopathology and immunohistochemistry confirmed CFT diagnosis. The patient recovered uneventfully and showed no recurrence at 2-month follow-up. Conclusions Small intestinal CFT is a rare cause of pediatric intestinal obstruction. High-frequency ultrasound demonstrated diagnostic capability in this specific case by identifying the pathognomonic triad of bowel wall thickening with calcifications and obstructive transition zone, facilitating timely preoperative assessment as a radiation-free initial imaging tool, with CT providing complementary confirmation of calcified lesions. Complete surgical resection achieved symptom resolution with no recurrence observed during available follow-up (2 months). This case supports considering small intestinal CFT in the differential diagnosis of children with unexplained chronic intestinal obstruction when the aforementioned pathognomonic triad (bowel wall thickening, calcifications, and obstructive transition zone) is observed, though larger pediatric cohort studies are required to validate this diagnostic approach.