case_images: PMC8714348_01
case_images: Screening chest CT scan that originally identified the 19 x 22 mm nodule in the left upper lobe of the lung (red circle). Left hilar adenopathy was also noted on presentation (yellow circle). Intralobular septal thickening was also noted.
case_images: CRIM2021-4256471.001.jpg
case_images: PMC8714348_01_CRIM2021-4256471.001.jpg
case_images: fig1
case_images: At that time, age-appropriate cancer screening was initiated, including a low-dose CT (computed tomography) scan of the thorax, which identified a 19 x 21 mm nodule, left hilar lymphadenopathy, and intralobular septal thickening in the left upper lobe (Figure 1) suspicious for pulmonary venous obstruction.
case_images: CT thorax with contrast sagittal (a) and coronal (b) representative views of the patient's mass measuring 3.3 x 2.4 cm. A sequence depicting the origination of the mass as it invades the left superior pulmonary vein before its extension in the left atrium (c).
case_images: CRIM2021-4256471.002.jpg
case_images: PMC8714348_01_CRIM2021-4256471.002.jpg
case_images: fig2
case_images: Thorax with contrast verified a mass in the aortopulmonary window measuring 3.3 x 2.4 cm (Figures 2(a) and 2(b)) and extending proximally into the left superior pulmonary veins and subsequently the left atrium (Figure 2(c)).
case_images: Transthoracic echocardiography (TTE) image of a mobile ecodensity measuring 3.0 cm x 1.6 cm. Doppler radar of the flow (not shown here) did not show obstruction of flow, which contributed to the patient's asymptomatic status.
case_images: CRIM2021-4256471.003.jpg
case_images: PMC8714348_01_CRIM2021-4256471.003.jpg
case_images: fig3
case_images: Transthoracic echocardiography (TTE) revealed a left ventricular ejection fraction (LVEF) of 61% with a 3.0 cm x 1.6 cm mobile echo density with a poorly defined variegated surface visualized in the left atrium attached to the roof of the atrium (Figure 3).
case_images: Histological sections of the left hilar mass. (a) Sections show cores of lung parenchyma replaced by a malignant neoplasm with significant pleomorphism, nuclear vacuoles, and abundant necrosis. Immunostaining showed positivity for (b) cytokeratin AE1/AE3, (c) CAM5.2, (d) p63, (e) CD5 (patchy), and (f) CD117 (patchy). The tumor cells are negative for PAX-8, napsin, TTF-1, CK7, CK20, S100, TTF-1, synaptophysin, chromogranin, and CDX-2 (not shown). This immunoprofile is supportive of a thymic origin and was diagnosed as poorly differentiated squamous cell carcinoma. There were not enough tissues to perform ancillary molecular studies.
case_images: CRIM2021-4256471.004.jpg
case_images: PMC8714348_01_CRIM2021-4256471.004.jpg
case_images: fig4
case_images: The tumor cells had an immune profile that was supportive of thymic origins with positive staining for cytokeratin ae1/ae3, CAM5.2, p63, CD5 (patchy), CD117 (focal and patchy), and negative staining for PAX-8, napsin, TTF-1, CK7, CK20, S100, synaptophysin, chromogranin, and CDX-2 (Figure 4).