[Inflammatory pseudotumors of the lung and trachea]

Inflammatory pseudotumors (synonym: plasma cell granulomas) of the lung and trachea are a group of non-neoplastic lesions of unknown etiology which may occur at any age. The complex histomorphology und proliferative capacity of these pseudotumors may result in diagnostic difficulties during intraoperative frozen section analysis. Four cases of inflammatory pseudotumors of the respiratory tract (three pulmonal, one tracheal pseudotumors) are reported. One patient (16 years, female) suffered from sudden chest pain with dyspnoe, caused by obstruction of the right main bronchus due to an intraluminal pseudotumor. Because of the intraoperative diagnosis of a malignant histiocytoma, sleeve resection of the right main bronchus with bronchotracheal anastomosis was performed. Eight years postoperative, the patient is still disease-free. Another patient (52 years, male) developed multiple inflammatory pseudotumors in both lungs with direct infiltration of the mediastinum. After three thoracotomies, there is still residual disease in the mediastinum. The third patient (52 years, male) developed an inflammatory pseudotumor in the right upper lobe after irradiation therapy for hypopharyngeal carcinoma several years before. The last case in this series is a patient (43 years, male) with suspected bronchial carcinoma in the left lower lobe. The intraoperative frozen section analysis interpreted this lesion as an bronchioloalveolar carcinoma, but the diagnosis was corrected in the paraffin embedded specimens. Clinical presentation, size and number of these tumors are very variable. Despite their rarity, inflammatory pseudotumors should be considered in the differential diagnosis.