Inflammatory myofibroblastic tumor in children: a report from Texas Children’s Rare Tumor Registry
Baylor College of Medicine
Background: Inflammatory myofibroblastic tumor (IMT) is a rare locally aggressive tumor of intermediate malignant potential. Surgical resection is often curative for localized tumors, however, up to 25% of tumors recur. Objective: In this study, we describe the presentation, treatment and outcome of children with IMT at Texas Children’s Hospital. Design/Method: A retrospective chart review was conducted on patients diagnosed with IMT between August 1994 and March 2018. Results: Eighteen patients were identified, ten males (55.6%) and eight females (44.4%), with a median age of 7.4 years (0-16 years) at diagnosis. Primary site included abdomen (38.9%, n=7), lung (33.3%, n=6), bladder (11.1%, n=2), neck (5.6%, n=1), larynx (5.6%, n=1) and heart (5.6%, n=1). Patients presented with symptoms related to the site of involvement, such as abdominal pain and hematuria for abdominal masses, and cough and hemoptysis for lung masses. Up front surgery was attempted in fifteen patients (83.3%); complete resection (CR) was achieved in six patients (33.3%), gross total resection (GTR) in seven (38.9%), and partial resection (PR) in two (11.1%). Two patients with GTR received adjuvant celecoxib. Three patients (16.7%) received neoadjuvant therapy (chemotherapy in 2, NSAID- 1); two of them developed disease progression. 1/7 patients with GTR had relapse and 1/2 patients with PR has disease progression. 3/4 patients who had relapse/progression had lung primary. All the patients with CR remained disease-free at last follow-up. One patient with an abdominal mass who progressed on celecoxib died due to post-operative hemorrhage. The 3-year event free and overall survival for the entire group was 76.4% and 94.1% respectively. Of the 15 patients assessed for ALK expression by immunohistochemistry, nine were positive (60.0%); of the 13 patients assessed for ALK gene rearrangement, seven were positive (53.8%). Only one patient screened for both tumor characteristics showed a discrepancy between results, testing positive for ALK expression but negative for ALK mutation. Conclusion: Children with IMT who undergo complete resection have excellent prognosis. Intrathoracic IMT may be associated with increased recurrence risk due to difficulty in achieving complete resection.