Airway-Invasive Pulmonary Aspergillosis

Fig. 3.10 IgG4-related lung disease manifesting as multifocal areas of consolidation and nodules in both lungs in a 51-year-old man. (a, b) Lung window images of CT scans (5.0-mm section thickness) obtained at levels of the aortic (a) and azygos (b) arches, respectively, show patchy areas of consolidation (arrows) and nodules (open arrows) in both lungs. Axial and peripheral interstitial thickening is also observed in the left lung. (c) Low-magniÞcation (×2) photomicrograph of

pathologic specimen obtained from a nodule in the right upper lobe demonstrates a relatively well-deÞned subpleural nodule (arrows). (d) Low-magniÞcation (×8) photomicrograph discloses lymphoplasmacytic inÞltration along with irregular Þbrosis (arrows) and obliterated vascular structure (open arrows). IgG4 and CD43 immunohistologic staining depicted positive results

Airway-Invasive Pulmonary Aspergillosis

Pathology and Pathogenesis

Airway-invasive pulmonary aspergillosis is characterized histologically by liquefaction necrosis and neutrophilic inÞltrate, which is centered at membranous and respiratory bronchioles. Vascular inÞltration and coagulative necrosis are usually absent or minimal in extent [26] (Fig. 3.8).

Symptoms and Signs

Airway-invasive pulmonary aspergillosis predominantly affects severely immunocompromised patients, particularly those with AIDS, heartÐlung or lung transplantation, and hematologic malignancy. While most patients with lung transplantation are asymptomatic, those with AIDS and

hematologic malignancy are usually symptomatic with dyspnea, inspiratory wheezes, fever, and nonproductive cough. Airway obstruction may result in atelectasis and severe respiratory failure [32].

CT Findings

HRCT demonstrates centrilobular nodules, tree-in-bud signs, and patchy areas of consolidation, often in a peribronchial distribution [26] (Fig. 3.8). Wall thickening of the trachea or the bronchi may be seen in tracheobronchitis.

CT–Pathology Comparisons

CT Þndings of centrilobular small nodules, tree-in-bud signs, and patchy areas of consolidation correspond to the foci of

Fig. 3.11 Lymphomatoid granulomatosis appearing as patchy areas of consolidation or nodules in both lungs in a 70-year-old man. (aÐc) Lung window images of thin-section (1.5-mm section thickness) CT scans obtained at levels of the great vessel takeoff (a), aortic arch (b), and lower lobar branch (c), respectively, show patchy areas of nodules or variable size and morphology (arrows) in both lungs. Also note airÞlled cysts in the right upper lobe and pneumothorax, small in amount

and in right pleural space, due to previous lung biopsy. (d) LowmagniÞcation (×2) photomicrograph of pathologic specimen obtained from a nodule in the left lower lobe demonstrates a relatively welldeÞned subpleural nodule (arrows) surrounding central bronchovascular structures (BV). (e) Low-magniÞcation (×10) photomicrograph discloses. Inset: positive staining for CD3+