Case Report
Copyright ©2010 Baishideng. All rights reserved
World J Gastroenterol. Jun 7, 2010; 16(21): 2698-2701
Published online Jun 7, 2010. doi: 10.3748/wjg.v16.i21.2698
Huge pelvi-abdominal malignant inflammatory myofibroblastic tumor with rapid recurrence in a 14-year-old boy
Chia-Hsun Lu, Hsuan-Ying Huang, Han-Koo Chen, Jiin-Haur Chuang, Shu-Hang Ng, Sheung-Fat Ko
Chia-Hsun Lu, Shu-Hang Ng, Sheung-Fat Ko, Department of Radiology, Chang Gung Memorial Hospital- Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung Hsien, 833, Taiwan, China
Hsuan-Ying Huang, Han-Koo Chen, Department of Pathology, Chang Gung Memorial Hospital- Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung Hsien, 833, Taiwan, China
Jiin-Haur Chuang, Department of Pediatric Surgery, Chang Gung Memorial Hospital- Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung Hsien, 833, Taiwan, China
Author contributions: Lu CH and Ko SF were the guarantors of integrity of the study; Ko SF, Huang HY and Chuang JH provided the study concepts and design; Lu CH, Chen HK and Ng SH performed the literature research; Lu CH, Huang HY and Chen HK performed the clinical and pathological studies and data acquisition; Lu CH and Ko SF prepared the manuscript; Ko SF, Huang HY and Chuang JH provided manuscript definition of intellectual content and manuscript editing; all authors approved the final version of the manuscript.
Correspondence to: Sheung-Fat Ko, MD, Department of Radiology, Chang Gung Memorial Hospital- Kaohsiung Medical Center, Chang Gung University College of Medicine, 123 Ta-Pei Road, Niao-Sung Hsiang, Kaohsiung Hsien, 833, Taiwan, China. sfa.ko@msa.hinet.net
Telephone: +886-7-7317123 Fax: +886-7-7318762
Received: February 10, 2010
Revised: March 24, 2010
Accepted: March 31, 2010
Published online: June 7, 2010
Abstract

Inflammatory myofibroblastic tumor (IMT) is an uncommon benign neoplasm with locally aggressive behavior but malignant change is rare. We report an unusual case of pelvic-abdominal inflammatory myofibroblastic tumor with malignant transformation in a 14-year-old boy presenting with abdominal pain and 9 kg body weight loss in one month. Computed tomography revealed a huge pelvi-abdominal mass (30 cm), possibly originating from the pelvic extraperitoneal space, protruding into the abdomen leading to upward displacement of the bowel loops, downward displacement of the urinary bladder, massive central necrosis, a well-enhanced peripheral solid component with prominent peritumoral vascularity. Subsequent examination confirmed the computed tomographic findings. Histopathologic examination revealed proliferative epitheloid and spindle cells, inflammatory cell infiltration and high mitotic counts. Immunohistochemistry was strongly positive for anaplastic lymphoma kinase and revealed a high proliferative index (ki-67 = 40%). DNA sequencing and electronic microscopy further confirmed the primitive fibroblastic cell phenotype of the tumor and a final diagnosis of inflammatory myofibroblastic tumor with malignant transformation was established. Rapid tumor recurrence was noted 20 d after radical tumor resection. To our knowledge, this is the largest documented case of IMT in a pediatric patient and the first report of IMT with malignant transformation originating from the pelvic extraperitoneal space.

Keywords: Inflammatory myofibroblastic tumor, Malignant transformation, Pediatric patient, Pelvis, Extraperitoneal space, Computed tomography