Inflammatory myofibroblastic tumor of the paranasal sinuses

A 4-year-old boy was presented by his parents with unilateral nasal obstruction and indolent nuchal lymphadenopathy on the left that had been present for several months. Shortly before, an adenotomy had been performed at another hospital. In the endonasal clinical examination, a polypoid mass was found in the left middle meatus. Cranial MRI diagnostics revealed a T1 isointense and T2 hypointense soft tissue proliferation extending from the ostium of the maxillary sinus to the ethmoidal cells. A more precise etiologic classification was not possible based on the radiologic results. For histological confirmation, an endoscopic, endonasal complete resection of the mass was performed. The tumor showed a mixed histological picture with extensive infiltrates of lymphocytes, plasma cells and histiocytes. The genetic examination with detection of a breakage event of the ALK gene (2p23.3) provided the decisive clue. The clinical and radiological controls showed no tumor recurrence up to 2 years postoperatively. Inflammatory myofibroblastic tumors are an extremely rare intermediate neoplasia within the group of inflammatory spindle cell tumors, with a high local recurrence rate but only a low metastatic potential. Epidemiologically, the disease is more common in children and adolescents and most frequently affects the abdominal cavity. Manifestations in the head and neck area are scarce. Symptomatic manifestations are primarily due to displacement effects of tumor growth such as pain, dyspnea, obstruction or epistaxis. Diagnosis is made by genetic analysis with evidence of ALK translocation (50-60% of cases) in conjunction with the histological image. Surgical resection is the only curative therapeutic option. Systemic therapies are only used for inoperable symptomatic tumors.