case_images: PMC11827422_01
case_images: Timeline. A graphic depiction of the timeline of events in this case.
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case_images: f1
case_images: This study presents a case of a spindle cell tumor with a BRAF mutation detected through pathological examination ( Figure 1 ).
case_images: Preoperative abdominal ultrasound of an infant with congenital fibrosarcoma. An abnormal echo mass is seen in the right upper abdomen, with a range of approximately 31 x 19 mm, unclear boundaries, and uneven internal echoes.
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case_images: f2
case_images: Preoperative abdominal ultrasound ( Figure 2 ) showed the following findings: lower abdomen showing dilated intestines with poor peristalsis; an abnormal echo mass in the right upper abdomen, approximately 31 x 19 mm in size with unclear borders and uneven internal echogenicity, surrounded by enhanced mesenteric echoes; another hypoechoic mass in the right middle lower abdomen measuring 27 x 23 mm, with clear borders and uniform internal echogenicity; and peripheral blood flow signals visible.
case_images: Upright abdominal plain film.
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case_images: f3
case_images: Abdominal X-ray ( Figure 3 ) showed intestinal gas accumulation, but no significant bowel dilation was noted, and multiple gas-fluid levels were seen in the middle upper abdomen.
case_images: Intraoperative view of resection of tumor and diseased bowel in a patient with infantile fibrosarcoma.
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case_images: Upon exploration, a large amount of turbid ascitic fluid was observed, and a small intestinal mass, approximately 16 cm in size, was found protruding into the lumen ( Figure 4 ).
case_images: Pathomorphologic findings in a patient with infantile fibrosarcoma. (A, B) Dense spindle-shaped cells arranged in bundles, with dilated blood vessels visible. (C) CD10 partially (+). (D) Cyclin D1 (partially +).
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case_images: f5
case_images: Immunohistochemistry ( Figure 5 ) showed that the tumor cells were positive for S-100 (focal +), smooth muscle actin (SMA) (partially +), CD10 (partially +) ( Figure 5C ), CD56 (partially +), P53 (hotspot, approximately 20%), Ki-67 (hotspot, approximately 30%), CD99 (weak +), SOX10 (-), caldesmon (-), CD34 (-), CD117 (-), ALK (-), CK (-), beta-catenin (-), NTRK (-), NKX2.2 (-), DOG-1 (-), desmin (-), ALK(D5F3) (-), negative for ALK (D5F3)-Neg, negative for AE1/AE3, negative for CK8/18, partial (+) for cyclin D1 ( Figure 5D ), negative for DDIT3, negative for desmin, negative for DOG1, negative for D2-40, negative for GLI1, negative for
case_images: Location mapping of variant sites in the genome and proteins. Mutation type: insertion-deletion mutation; genomic location: NM_004333 exon15 g.140453136 insAAT and c.1798_1799insATT p.V600delinsDL (variant allele frequency, VAF 26.1%).
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case_images: f6
case_images: MDM2, negative for MSA, negative for SMA, and negative for STAT6. Molecular testing using panoramic DNA sequencing and PLUS DNA next-generation sequencing (NGS) detected the BRAF p.V600delinsDL mutation ( Figure 6 ).