Abstract
Inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal neoplasms containing spindle cells and inflammatory components that can be locally aggressive. They have unclear biological behavior and may recur after resection. A 31-year-old woman presented with three months of cough, fatigue, weight loss, abdominal pain, anemia, and elevated inflammatory markers. CT showed a large well-circumscribed enhancing mass in the right colic mesentery. The patient underwent a laparoscopic right colectomy. Pathologic review showed fascicular spindle cells with admixed chronic inflammatory cells. Cells stained diffusely positive for SMA and anaplastic lymphoma kinase (ALK), diagnostic of an IMT. Post-operatively, the patient reported symptom resolution and had normalization of lab values. She remains disease-free at 20 months. IMT is rare in adults, accounting for 0.7%-1.0% of lung tumors. Up to 30% of patients present with elevated inflammatory markers. On imaging, IMTs are soft tissue masses with variable enhancement and fibrosis, often suspected to be malignant neoplasms. Up to 80% of IMTs are driven by altered tyrosine kinase signaling and half of IMTs express ALK, which may be treated in unresectable/recurrent cases using ALK-inhibitors. IMT may recur in 10%-15% of patients. The roles of adjuvant treatments are unclear given the rarity and unpredictable biological behavior. Long-term follow-up with regular radiologic and laboratory surveillance is recommended given possible local recurrence. IMTs are best managed in a multidisciplinary setting given their unpredictable nature. Surgery is the mainstay of IMT treatment with long-term control expected in >80% of adult patients.