Inflammatory myofibroblastic tumor of the lung--a case report

Abstract

A 45-year-old man presented with a six-month history of progressive dyspnea with productive cough and wheezing. The patient was a heavy smoker and had a history of tongue cancer, hypertension, and asthma. Chest X-ray and computed tomography showed a mass lesion in the left hilar region and total collapse of the upper left lobe of the lung. Bronchoscopy revealed a whitish solid tumor obstructing the left upper lobe bronchus. Positron emission tomography showed increased tracer uptake in the lesion. A thoracoscopic lobectomy of the left upper lobe of the lung was performed. The final pathologic diagnosis was inflammatory myofibroblastic tumor.

Figure 1

(A) Chest plain film. A protruding mass shadow is seen in the left hilar region. The shadow of the left bronchus stops at the mass. Costodiaphragmatic angles are clear. There is increased density over the left lung field with elevation of the left side of the diaphragm. These findings are indicative of a hilar mass obstructing the bronchus with collapse of the left upper lobe of lung. (B) Contrast computed tomography (CT) image, distal part of the tumor. The distal bronchus is dilated and filled with secretions. The margin between the lung parenchyma and tumor is indistinct. (C) Positron emission tomography (PET) and CT, proximal part of the tumor. An endobronchial tumor with high tracer uptake and clear margins is visible.

Figure 2

Bronchoscopic exam shows a whitish tumor obstructing the left upper bronchus. Gross. The tumor impacted the whole bronchus with clear margins. Microscopically, the biopsy specimen is composed of spindle cells with fibroblastic and myofibroblastic differentiation arrayed in fascicles. (A) The tumor is mostly limited within the bronchi. In a few foci, pushing of tumor margin to the lung parenchyma is noted (×20; ×100). Immunohistochemical study demonstrated (B) vimentin (+) (×200), and (C) cytokeratin (focal +), (×200).