A case report of tracheal inflammatory myofibroblastic tumor in a 34-week pregnant woman misdiagnosed with asthma

RATIONALE Inflammatory myofibroblastic tumor (IMT) is an uncommon neoplastic entity with a tendency of local recurrence and a low risk of distant metastasis. Involvement of trachea is extremely rare. PATIENT CONCERNS A 34-week pregnant woman previously diagnosed with asthma for 2 months was admitted with persistent wheezing and hemoptysis. A computed tomography scan and bronchoscopy revealed a gigantic polyp in the trachea. DIAGNOSES Tracheal inflammatory myofibroblastic tumor. INTERVENTIONS The mass was removed with an electrocautery snare and identified histologically as an IMT. Further immunochemical staining showed strong positive staining for smooth muscle actin and platelet-derived growth factor receptor α (PDGFRA), weak positive staining for caldesmon, and negative staining for anaplastic lymphoma kinase (ALK)1, desmin, S-100, and CD34. The tracheal IMT strongly expressed estrogen receptor-α (ER-α), which indicated that the development of this rare IMT might have been associated with hormone fluctuations that occurred during the pregnancy. OUTCOMES Follow-up and histological analyses revealed no evidence of recurrence and metastasis. LESSONS This report describes an extremely rare case of a tracheal IMT that presented a diagnostic dilemma for the clinician and the pathologist. Tracheal IMT is a challenge for the clinician in diagnosis due to the nonspecific clinical presentation. Histology and immunohistochemistry are required to reach an accurate diagnosis of IMT.