PMC5410482_01
A chest X-ray at the first visit showed bilateral multiple nodules.
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A chest X-ray revealed bilateral multiple nodules (Fig. 1).
Chest CT at the first visit showed well-defined non-calcified nodular lesions of the bilateral lobes.
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A chest computed tomography (CT) scan showed well-defined non-calcified nodular lesions of the bilateral lobes, with a maximum diameter of 11 mm (Fig. 2). 18-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) showed slightly positive signals (SUVmax: 1.0) in multiple lung nodules.
(a) A surgical specimen of the parotid gland showing tumor cells, consisting of epithelial and mesenchymal cells, and venous invasion [Hematoxylin and Eosin (H&E) staining, 4xmagnification]. (b) Tumor cells invading into subcapsular spaces in the parotid gland (H&E staining, 4xmagnification). (c) A surgical specimen of lung showing a well-demarcated whitish solid nodule (H&E staining, 1xmagnification). (d) Tumor cells in the metastatic lesion consisting of epithelial and mesenchymal cells (H&E staining, 10xmagnification).
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These pathological findings were highly similar to the current findings, and thus the tumors were considered to have the same origin (Fig. 3).
(a) Immunohistochemistry showing positivity for pan-cytokeratin AE1/AE3 in the epithelial cells and negativity in the mesenchymal cells (10xmagnification). (b) Immunohistochemistry showing positivity for S-100 protein in the epithelial cells (20xmagnification). (c) Immunohistochemistry showing positivity for glial fibrillary acidic protein (GFAP) in the mesenchymal cells (20xmagnification).
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The mesenchymal cells were negative for AE1/AE3 and positive for glial fibrillary acidic protein (GFAP) in the border zone between the epithelial and mesenchymal cells (Fig. 4).
Contrast-enhanced MRI (T2WI) showed a 17-mm tumor in the right parotid gland.
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Supporting the theory that the new tumor represented a local recurrence of the previous parotid gland tumor, a 17-mm section of the right parotid gland tumor was examined by contrast-enhanced magnetic resonance imaging (MRI) (Fig. 5).