PMC9052980_01
Contrast-enhanced computed tomography (CT), lung perfusion scintigraphy, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT, and histology of the right subclavian lymph node biopsy specimens during diagnostic evaluation. (a) Chest CT shows an infiltrative shadow in the right middle lobe (black asterisk). (b and c) Contrast-enhanced CT shows mediastinal and bilateral hilar lymphadenopathy (white arrows) without obvious findings of pulmonary thromboembolism or mass in any organs indicating malignancy. (d-g) Lung perfusion scintigraphy shows multiple subsegmental perfusion defects (black arrows) in the subpleural portion of both lungs. Note: They are relatively small and light compared with the typical characteristics of chronic thromboembolic pulmonary hypertension. (h-j) FDG-PET/CT shows multiple abnormal uptakes (white asterisks) in the mediastinal, bilateral hilar, bilateral supraclavicular, and subclavian lymph nodes. (k) Lymph nodes are replaced by predominantly solid sheets and nests of tumor cells with very focal gland formation with mucin (arrows), suggesting metastatic adenocarcinoma (hematoxylin and eosin staining). Immunohistochemistry panels show that (l) cytokeratin (CK) 7 (brown), (m) thyroid transcription factor-1 (brown), and (n) napsin A (brown) are all positive. Considering that p40, CK5/6, CK20, and thyroglobulin were negative markers (data not shown), these results indicate that lung adenocarcinoma is the most probable primary lesion
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Contrast-enhanced CT demonstrated mediastinal and bilateral hilar lymphadenopathy with an infiltrative shadow in the right middle lobe, without any obvious findings of pulmonary thromboembolism up to distal subsegmental arteries as far as we can see or a mass in any organ indicating malignancy (Figure 1a-c). Lung perfusion scintigraphy demonstrated multiple subsegmental perfusion defects in the subpleural portion of both lungs, which were relatively small compared with the typical characteristics of CTEPH (Figure 1d-g). Following the initiation of venoarterial extracorporeal membrane oxygenation (VA-ECMO), 18F-fluorodeoxyglucose positron emission tomography-CT showed abnormal uptake in the mediastinal, bilateral hilar, bilateral supraclavicular, and subclavian lymph nodes (Figure 1h-j). Surgical biopsy of the right subclavian lymph nodes revealed metastatic adenocarcinoma (Figure 1k). Immunohistochemistry panels indicated lung adenocarcinoma as the most probable primary lesion, as evidenced by positive markers of cytokeratin (CK) 7, thyroid transcription factor-1, and napsin A (Figure 1l-n), and with negative markers of p40, CK5/6, CK20, and thyroglobulin.