Ishibayashi Kenichi, Kitamura Hirotaka, Tsuyama Sho, Yoshikawa Akane, Zasu Maika, Ikku Yusuke, Asakawa Tetsuya, Gunjikake Katsuya, Kito Yosuke, Yamaguchi Takahisa, Ohbatake Yoshinao, Terai Shiro, Katayanagi Kazuyoshi, Kadoya Shinichi, Minato Hiroshi, Bando Hiroyuki
Department of Gastroenterological Surgery, Ishikawa Prefectural Central Hospital, Kanazawa, Ishikawa, Japan.
Department of Diagnostic Pathology, Ishikawa Prefectural Central Hospital, Kanazawa, Ishikawa, Japan.
Surg Case Rep. 2025;11(1). doi: 10.70352/scrj.cr.25-0096. Epub 2025 Jun 10.
Malignant triton tumors (MTTs) are rare tumors histologically defined as malignant peripheral nerve sheath tumors with additional rhabdomyoblastic differentiation. MTTs occur more frequently in patients with neurofibromatosis type 1 (NF1). MTTs are most commonly found in the extremities, head and neck, and trunk; however, no cases in the mesentery have been reported. In this report, we describe a case of primary MTT of the mesentery in a patient with NF1.
A 29-year-old woman with NF1 visited a clinic for abdominal pain and was referred to our hospital for treatment of an abdominal tumor detected by CT. Contrast-enhanced CT showed a 20-cm irregular mass on the right side of the abdominal cavity. The mass was extensively bordered by the superior mesenteric vein (SMV), but there was no obvious distant metastasis. The patient was diagnosed with a mesenteric tumor with SMV invasion. An open biopsy was performed, and the histopathological diagnosis was MTT. The patient was discharged on the 11th day after surgery but returned to our hospital on the 17th day due to abdominal pain. The tumor had markedly enlarged on CT, and a semi-emergent tumor resection was performed. An enlarged mass was detected, but no peritoneal dissemination was observed. The tumor was in extensive contact with the SMV, but it could be dissected. A right hemicolectomy was performed, and the tumor was removed. Histopathological findings revealed a 26.5 × 17.5 × 9.5 cm tumor in the ileocolic mesentery. The dissected surface was negative for margins, with no exposed tumors. The histopathological diagnosis was MTT. Follow-up CT on postoperative day 14 revealed multiple peritoneal nodules. The patient was diagnosed with recurrent peritoneal dissemination and treated with two courses of doxorubicin and one course of pazopanib. However, she died 5 months postoperatively due to worsening peritonitis carcinomatosis.
We present a case of primary MTT of the mesentery. Our findings suggest that biopsy may lead to peritoneal dissemination. In patients with suspected MTT, such as those with NF1, abdominal cavity biopsy should be avoided, and diagnostic treatment should prioritize surgical resection.
恶性蝾螈瘤（MTTs）是一种罕见肿瘤，组织学上定义为具有额外横纹肌母细胞分化的恶性外周神经鞘瘤。MTTs在1型神经纤维瘤病（NF1）患者中更常见。MTTs最常发生于四肢、头颈部和躯干；然而，尚未有肠系膜部位的病例报道。在本报告中，我们描述了1例NF1患者发生的肠系膜原发性MTT。
一名29岁的NF1女性因腹痛就诊于一家诊所，因CT检查发现腹部肿瘤而转诊至我院治疗。增强CT显示腹腔右侧有一个20厘米的不规则肿块。该肿块广泛毗邻肠系膜上静脉（SMV），但无明显远处转移。患者被诊断为侵犯SMV的肠系膜肿瘤。进行了开放活检，组织病理学诊断为MTT。患者术后第11天出院，但因腹痛于第17天返回我院。CT显示肿瘤明显增大，遂进行了半急诊肿瘤切除术。发现肿块增大，但未观察到腹膜播散。肿瘤与SMV广泛粘连，但可以分离。进行了右半结肠切除术，切除了肿瘤。组织病理学检查发现回结肠系膜有一个26.5×17.5×9.5厘米的肿瘤。切除边缘的组织病理学检查为阴性，无肿瘤暴露。组织病理学诊断为MTT。术后第14天的随访CT显示多个腹膜结节。患者被诊断为复发性腹膜播散，并接受了两个疗程的阿霉素和一个疗程的帕唑帕尼治疗。然而，她在术后5个月因癌性腹膜炎恶化死亡。
我们报告了1例肠系膜原发性MTT病例。我们的研究结果表明，活检可能导致腹膜播散。在怀疑患有MTT的患者中，如NF1患者，应避免进行腹腔活检，诊断性治疗应优先考虑手术切除。
