Abstract Inflammatory myofibroblastic tumor (IMT) is a rare sarcoma composed ofmyofibroblastic and fibroblastic spindle cells accompanied with inflammatory cells. It has a low risk of recurrence and metastases. The estimated incidence is less than 1 in 1,000,000, with 50-60% of the reported cases occurring in children and adolescent young adults. 28-year-old male with history of smoking presented with dyspnea and hemoptysis. CT imaging revealed a right hilar mass concerning for malignancy. PET scan showed a 3.3 × 3.4 cm right hilar mass with uniform metabolic activity and no evidence of metastasis. He was referred to cardiothoracic surgery and underwent elective thoracotomy with right upper lobectomy, sleeve resection of the right bronchus, and mediastinal lymphadenectomy. Surgical pathology identified a spindle cell lesion measuring 4.8 cm and lymph nodes negative for metastasis. Immunohistochemistry revealed the tumor was positive for vimentin and ALK-1. The tumor was staged as T2b N0.The patient was seen three weeks post-lobectomy and was asymptomatic. After multidisciplinary team discussion, the decision was made to proceed with periodic surveillance using CT imaging without adjuvant therapy. IMTs are tumors primarily composed of myofibroblastic and fibroblastic spindle cells and are characterized by a high rate of recurrence but low rate of metastases. These are accompanied with inflammatory cells, especially lymphocytes and eosinophils. IMTs can occur in any location, with symptoms depending on primary location. The lungs are a common site. Common symptoms include pain, fever, decreased appetite, and hemoptysis.A tyrosine kinase fusion gene has been found to play a role in a large majority of cases. It has been theorized that anaplastic lymphoma kinase (ALK) oncogenic activation mechanisms are a key driver of tumor growth. They have been characterized in approximately 80% of IMTs, as was the case in our patient. While the etiology is unclear, it is thought that smoking, trauma, and IgG4-related diseases can lead to IMTs. Epstein-Barr virus and Human Herpesvirus-8 have also been found to be associated with IMTs. Our patient’s only risk factor was smoking. In localized disease, surgery is the treatment of choice with complete resection. Studies have shown that up to one-quarter of surgically treated tumors recur. No adjuvant therapy is recommended after resection. Some studies demonstrated adjuvant radiotherapy helped decrease local recurrence, though there is a lack of prospective data. Additionally, there are some studies that demonstrated the efficacy of steroids as an adjuvant treatment for IMTs. This abstract is funded by: None
Kong et al. (Fri,) studied this question.