PMC3561274_01
Chest thin-section CT on admission to our hospital. (a) A thin-section CT at the level of right upper lobe shows a 10-mm round, well-defined GGO nodule (arrow). There are slightly dilated veins or thickening of the interlobular septa (arrow heads). (b) Similar findings are seen also on the slice just above the focal GGO (arrow heads).
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F1
Chest thin-section CT scan showed a 10-mm pure GGO with a well-defined and smooth margin in the right upper lobe (Figure 1a). In addition, slightly dilated veins and thickening of interlobular septa were seen around the focal GGO (Figure 1a, b).
Screening chest CT at 2 years before CT examination at our hospital. A 7mm slice thickness CT shows a faint pure GGO in the right upper lobe (arrow), which is smaller than that of Figure 1.
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F2
The focal GGO was identifiable also on the previous CT for lung cancer screening when viewed retrospectively (Figure 2).
Histopathology of the resected lung tissue. (a) Photomicrograph (hematoxylin-eosin stain; original magnification, x2) shows a focal area of alveolar wall thickening with preservation of the intraalveolar airspaces, consistent with the focal GGO on thin-section CT (arrow). Partial collapse of this lesion is due to an artifact during the process of specimen production. (b) Photomicrograph (hematoxylin-eosin stain; original magnification, x10) shows alveolar wall thickening with fibrosis, and congestion(arrows). Alveolar bronchiolizations are also seen (arrowheads). (c) Photomicrograph (elastica Masson stain; original magnification, x4) near the focal fibrosis shows dilated arterioles (asterisk) with markedly thickened walls, one of which have resulted in luminal obliteration (black arrow), as well as dilated venules (white arrows). A transition from arteriolar wall to venular one is seen, suggesting a direct communication between them (arrow head).
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F3
Histopathological examination of the resected lung tissue revealed no evidence of malignancy but abnormally dilated arterioles, venules and lymph ducts with an area of peripheral focal fibrosis consisting of congestion, fibrotic septal thickening with preservation of the intraalveolar airspaces (Figure 3a-c). The dilated arterioles had thickened walls and were directly communicating with the venules (Figure 3c).