Clinicopathological Characteristics of Inflammatory Myofibroblastic Tumor: A Single Center Retrospective Cohort Study.

Background: Inflammatory myofibroblastic tumor (IMT) is a rare intermediate-grade neoplasm. It presents a great challenge in diagnosis and treatment. This study aims to identify the clinicopathological characteristics of IMT.

Methods: A retrospective study was conducted, enrolling patients with IMT at Peking Union Medical College Hospital from January 2013 to October 2023. Clinical information, treatments, and efficacy were analyzed.

Results: A total of 72 patients were enrolled, including 38 men and 34 women, with a median age of 46.5 years. The most common primary site included the lung (n = 15, 20.8%), intestinal tract (n = 8, 11.1%), abdominal cavity (n = 7, 9.7%), and nasal sinus (n = 5, 6.9%). Thirty patients harbored anaplastic lymphoma kinase (ALK) fusion genes; Sixty-five (90.3%) patients underwent surgical resection, and 11 of them had postoperative recurrence. Thirty patients received systemic therapy, including nonsteroidal anti-inflammatory drugs (n = 1), steroids (n = 5), chemotherapy (n = 7), targeted therapy (n = 2), and immune checkpoint inhibitor (n = 1).

Conclusions: The most common site of IMT is the lung. Surgery is the main treatment for IMT, and postoperative adjuvant therapy for ALK-positive patients needs to be focused. The molecular testing is essential for all patients diagnosed with IMTs. Systemic treatment needs further research.