Kyujo Lee1, Hyunwoo Kim1, Syungkyun Choi2, Il-Tae Jang3, Hyunjin Lee1

1Nanoori 2bko R&D Institute, Nanoori Hospital Suwon, Suwon, Republic of Korea
2Department of Orthopedic Surgery, Nanoori Hospital Gangnam, Gangnam, Republic of Korea
3Department of Neurosurgery, Nanoori Hospital Gangnam, Gangnam, Republic of Korea

Keywords: Anaplastic lymphoma receptor tyrosine kinase-negative inflammatory myofibroblastic tumor, triceps brachii.


Inflammatory myofibroblastic tumor (IMT) is a non-neoplastic benign lesion comprising various inflammatory cells, including myofibroblasts and vascular tissues. It is a rare tumor that sometimes shows similar signs and progression as malignant tumors. The anatomical sites of IMTs include the lungs, liver, orbit, skin, mesentery, and maxillary sinus, but they rarely occur in the limb musculoskeletal system. To our knowledge, no case of neurological symptoms caused by the tumor in the triceps brachii muscle has been reported. In this article, we report the case of a 42-year-old male patient with an IMT that grew rapidly in the triceps brachii muscle and consequently caused symptoms of ulnar nerve lesion owing to its increasing size. The patient showed no ulnar nerve lesion symptoms after undergoing wide excision and was diagnosed with anaplastic lymphoma receptor tyrosine kinase- negative IMT.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

The authors received no financial support for the research and/or authorship of this article.