[Inflammatory pseudotumors of the lung with severe course].

Pulmonary inflammatory pseudotumors are usually unique lesions of unknown etiology with good prognosis. We report two severe cases with mediastinal invasion, local recurrence, extrathoracic locations, one of them with a fatal evolution. Certain microscopic features, which were present in our cases (increased cellularity, nuclear pleomorphism, mitotic activity, focal necrosis, bizarre giant cells, vascular invasion), may have prognostic relevance in determining an aggressive behavior of these tumors. Surgical resection is the recommended treatment, and incomplete resection, as in our cases, seems to be a risk factor for developing recurrent inflammatory pseudotumor. Immunosuppressive therapy was ineffective as well as radiotherapy in one of our cases. Only high doses of corticosteroids seemed to slow the evolution of the disease.