PMC7836275_01
X-ray imaging showing fluid in pleural space, loss of pulmonary lobes volume and reticular opacification
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F1
X-ray imaging showed several pathologic features such as fluid in pleural space, loss of pulmonary lobes volume and reticular opacification (Fig. 1).
High-resolution computed tomography (HRCT): fluid in pleural cavity (A), interlobular septal thickening, mediastinal nodes enlargement (B)
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F2
High-resolution computed tomography (HRCT) (Fig. 2) displayed left lung base atelectasis, interlobular septal thickening and pleural effusion (left space - 65 ml, right space - 20 ml).
The haematoxylin and eosin staining shows multiple emboli of atypical epithelial cells (A, B). The cells have a characteristic signet - ring shape with a central, optically clear droplet of cytoplasmic mucin and eccentrically displaced nucleus (C). Magnification of 0.5x (A), 20x (B), 40x (C)
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F3
On high magnification, multiple emboli of atypical epithelial cells were found in pulmonary blood vessels (Fig. 3A). The cells had a characteristic signet - ring shape with a central, optically clear droplet of cytoplasmic mucin and eccentrically displaced nucleus (Figs. 3B and 3C).
Immunophenotyping of tumour cells: positivity for cytokeratin 7 (A), cytokeratin 20 (B), negativity for TTF1 (C). The biopsy was positive for mucin (D). Magnification of 10x
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F4
Immunohistochemistry (IHC) revealed i) positivity for cytokeratin 7, cytokeratin 20, cytokeratin 19, Ki67, high molecular weight cytokeratin and cytokeratin AE1/AE3 (Fig. 4) and ii) negativity for CD68, thyroid transcription factor 1 (TTF1), cytokeratin 5/6, p63, synaptophysin, CD10, napsin A, PAX-8, prostate specific membrane antigen (PSMA), adult renal cell carcinoma (RCC), CD56 and chromogranin A.
The haematoxylin and eosin staining of signet ring cell gastric adenocarcinoma. Magnification of 20x
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F5
Biopsy was taken and histopathology confirmed the diagnosis of signet ring cell gastric adenocarcinoma (Fig. 5) with haematogenous dissemination involving pulmonary vessels.