Correct!
2. The thoracic CT shows features suggesting previous granulomatous infection
The thoracic CT shows abnormal soft tissue with foci of calcification surrounding the vessels and the bronchi extending from the hilar regions into the segmental regions bilaterally. This abnormal tissue narrows the right inferior pulmonary vein, the right lower lobe bronchus, and the left interlobar and lower lobe pulmonary arteries. The arterial narrowing, and bronchial artery hypertrophy, can superficially resemble chronic thromboembolic disease, but the narrowing in this circumstance is extravascular in nature, rather than caused by abnormal tissue centered on the wall of the pulmonary arteries- therefore, chronic thromboembolic disease and pulmonary arterial vasculitis are not correct answers. Metastatic malignancy can certainly result in abnormal peribronchial tissue, reflecting lymphadenopathy, but the presence of calcification argues strongly against a metastatic malignancy in this patient. Some sarcomas, notably osteogenic sarcoma and chondrosarcoma, may ossify or calcify, but sarcomas far more commonly affect the lung parenchyma, not mediastinal and peribronchial nodal tissue. Sarcoidosis commonly causes peribronchial and mediastinal lymphadenopathy, and not infrequently, these lymph nodes may show calcification. Often the calcification is less dense than seen in this patient, and lymph nodes related to sarcoidosis are commonly fairly symmetric. The abnormal calcified soft tissue in this patient is bilateral, but is rather asymmetric. Finally, although sarcoidosis is a fibrosing disease, the degree of mass effect on adjacent structures- the right inferior pulmonary vein, right lower lobe bronchus, and left interlobar and lower lobe pulmonary arteries- is atypical for the diagnosis of sarcoidosis. Rather, the presence of the calcification within the abnormal peribronchial soft tissue is strongly suggestive of previous granulomatous infection, and the mass effect suggests an associated fibrosing reaction.
Based on the data thus far, what is the most likely diagnosis for this patient? (Click on the correct answer to proceed to the ninth and final page)