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Inflammatory Myofibroblastic Tumor of the Knee in a 7-year-old Child: A Case Report

https://doi.org/10.5937/medrec2504096J

UDC 616.718-006.03-002-053.5

Aleksandar Janković¹, Zoran Marjanović¹, Nikola Bojović¹, Nikola Vacić¹, Dejana Božić²

1Clinic for Pediatric Surgery, Orthopedics and Traumatology, University Clinical Center Niš, Niš, Serbia

2Institute for Health Protection of Mother and Child “Dr Vukan Čupić”, Belgrade, Serbia

Case Report

Abstract

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal neoplasm with intermediate malignant potential, typically occurring in children and young adults. We report a case of seven-year-old boy with a well-defined, extra-articular medial knee mass. MRI demonstrated a solid lesion with strong homogeneous enhancement without joint or bone invasion. Complete surgical excision was performed. Histopathology revealed myofibroblastic spindle-cell proliferation in a myxoid stroma with mixed inflammatory infiltrate. Immunohistochemistry showed SMA positivity and ALK negativity; molecular testing identified ROS1 rearrangement and COL1A1–PDGFRα fusion. The postoperative course was uneventful with no recurrence on follow-up. This case underscores the value of comprehensive molecular profiling in atypical IMT locations and the potential for targeted therapy in unresectable or recurrent disease.

Key words: inflammatory myofibroblastic tumor, knee, child, ROS1, PDGFRα, ALK-negative

References

  1. Choi JH. Inflammatory Myofibroblastic Tumor: An Updated Review. Cancers (Basel) 2025;17(8):1327.
  2. Gros L, Dei Tos AP, Jones RL, Digklia A. Inflammatory Myofibroblastic Tumour: State of the Art. Cancers (Basel) 2022;14(15):3662.
  3. Siemion K, Reszec-Gielazyn J, Kisluk J, Roszkowiak L, Zak J, Korzynska A. What do we know about inflammatory myofibroblastic tumors? – A systematic review. Adv Med Sci 2022;67(1):129-38.
  4. Sbaraglia M, Bellan E, Dei Tos AP. The 2020 WHO Classification of Soft Tissue Tumours: news and perspectives. Pathologica 2021;113(2):70-84.
  5. Chmiel P, Słowikowska A, Banaszek Ł, et al. Inflammatory myofibroblastic tumor from molecular pathology to targeted therapies. Oncol Res 2024;32(7):1141–62.
  6. Casanova M, Brennan B, Alaggio R, et al. Inflammatory myofibroblastic tumor: The experience of the European pediatric Soft Tissue Sarcoma Study Group (EpSSG). Eur J Cancer 2020;127:123-29.
  7. Da M, Qian B, Mo X, et al. Inflammatory Myofibroblastic Tumors in Children: A Clinical Retrospective Study on 19 Cases. Front Pediatr 2021;9:543078.
  8. Raitio A, Losty PD. Treatment and outcomes in pediatric inflammatory myofibroblastic tumors – A systematic review of published studies. Eur J Surg Oncol 2024;50(7):108388.
  9. Comandini D, Catalano F, Grassi M, et al. Outstanding Response in a Patient With ROS1-Rearranged Inflammatory Myofibroblastic Tumor of Soft Tissues Treated With Crizotinib: Case Report. Front Oncol 2021;11:658327.
  10. Mai S, Xiong G, Diao D, Wang W, Zhou Y, Cai R. Case report: Crizotinib is effective in a patient with ROS1-rearranged pulmonary inflammatory myofibroblastic tumor. Lung Cancer 2019;128:101-4.
  11. Yıldırım ÜM, Kebudi R, Zülfikar B, Bilgiç B. Inflammatory myofibroblastic tumor in children: clinical characteristics and treatment outcomes with a focus on targeted therapies. Turk J Pediatr 2025;67(1):51–60.
  12. Lovly CM, Gupta A, Lipson D, et al. Inflammatory myofibroblastic tumors harbor multiple potentially actionable kinase fusions. Cancer Discov 2014;4(8):889-95.
  13. Liu M, Zhu D. Two cases of inflammatory myofibroblastic tumor treated with targeted drugs: A case report. Medicine (Baltimore) 2024;103(21):e38136.

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