PMC9358455_01
Images of chest computed tomography (CT). Images of chest CT at the initial visit (A), at the admission (B), and before the surgical lung biopsy (C). Expansion of the area of multiple micronodules with surrounding ground glass opacities in both lungs were shown.
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Because his chest CT showed multiple micronodules with surrounding GGOs in both lungs (Fig. 1A) and slight enlargement of mediastinal lymph nodes, he was referred to the Department of Respiratory Medicine and Allergology. His chest CT showed increases in the areas of micronodules and GGOs (Fig. 1B) compared with those at the initial visit (Fig. 1A). After admission, the dose of prednisolone was increased to 50 mg per day, but partial pressure of oxygen in arterial blood dropped to 55.4 mmHg with 1 L/min supplemental oxygen via nasal cannula and further radiological deterioration was confirmed on chest CT (Fig. 1C).
Histopathological findings of lung specimens obtained by surgical lung biopsy. (A) A low power view of the lung specimen showed tumor embolization in nearly all small pulmonary arterioles associated with dilation (hematoxylin-eosin). (B) A high-power view (hematoxylin-eosin) showed tumor cells formed by renal cell carcinoma cells with papillary or glandular structures in. The arrows indicate the muscle layer of the arteries. (C) Immunostaining for PAX8 showed tumor cells positivity for PAX8.
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The lung biopsy revealed embolization of tumor cells into nearly all small pulmonary arterioles associated with extensive dilation. (Fig. 2A and B). The tumor cells were positive for PAX8 (Fig. 2C) but negative for thyroid transcription factor-1, which finding supported renal cell carcinoma origin.
Images of enhanced-contrast CT findings at diagnosis of renal cell carcinoma. (A) An internal heterogeneous mass in the morphologically preserved left kidney and invasion of the left renal vein are shown. (B) There were no massive tumor emboli in large pulmonary arteries.
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A whole-body contrast-enhanced CT to identify the primary lesion showed a heterogeneous mass invading the left renal vein in the left kidney (Fig. 3A), but no massive embolus in the main pulmonary arteries (Fig. 3B).