Inflammatory myofibroblastic tumor of the upper arm: A case report.

Rationale: Inflammatory myofibroblastic tumor (IMT) is an uncommon benign myofibroblastic tumor that usually occurs in the lung, mediastinum, abdomen and vulvovaginal region. IMT of the upper arm is exceedingly rare with unknown etiology. Pathology plays a major role in the diagnosis of IMT, and radiological characteristics of the condition are crucial for differential diagnosis.

Patient Concerns: A 62-year-old woman was admitted to our hospital for a complaint of a mass in her left upper limb with progressive numbness in the extremity. Ultrasound examination of the brachial artery (BA) revealed a hypoechoic mass with well-defined borders and a substantial blood flow, and the mass was also shown to be greatly enhanced on computed tomography (CT) and magnetic resonance imaging (MRI).

Diagnosis: The subsequent histopathological and immunohistochemical studies led to the diagnosis of IMT.

Intervention: The patient was referred for surgery. The soft tissue tumor resection, left median nerve release operation, brachial artery vascular grafting, and arterial anastomosis were performed.

Outcome: Favorable outcome was observed. The patient recovered well from the procedure and did not experience any further complications or tumor recurrence.

Lessons: In this report, we describe a case of IMT of the upper arm with BA involvement. The case expands the differential diagnosis of limb neoplasm and broadens the understanding of its ultrasonic and radiological imaging features. It also serves as a further example of an uncommon region distinct from conventional IMT. Further studies on the etiology and therapeutic strategies are needed.