PMC5994262_01
(a) Chest X-ray showed 6 x 4.5 cm white opaque lesion in mediastinal area (blue arrow) and (b) CT-scan revealed hypodense mass 6.7 x 7.5 cm, suggesting inferoanterior mediastinal cyst (blue arrow). Encapsulated cystic lesion compressed adjacent aorta and pericardium.
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fig1
Thoracic CT-scan revealed a cystic lesion, 6.7 x 7.5 cm located in inferior part of the anterior mediastinum (Figure 1).
(a) An Island of pancreas tissue bordered by thick fibrous tissue with pancreatic interlobular duct around it (H&E-4x). (b) Pancreas tissue consists of exocrine gland with eosinophilic granular cytoplasm and endocrine cells (Islets of Langerhans) (H&E-10x). (c) Increase in the endocrine portion (Islets of Langerhans) of pancreatic tissue (H&E-40x). (d) Mediastinal cyst lined by simple cuboid and columnar epithelium (H&E-10x). (e) Hyperplasia of thymic gland was observed (HE-4x). (f) Normal appearance of lymphocytes and Hassall's corpuscles (H&E-10x).
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fig2
It consisted of acinar exocrine cells with interlobular ducts and abundant endocrine cells (Islets of Langerhans) (Figure 2).
Immunohistochemical staining. (a and b) High expression of insulin in pancreatic beta cells of islets of Langerhans (10x-40x). (c and d) Strong positivity of chromogranin in islets of Langerhans (10x-40x). (e and f) Cytokeratin showed strong positivity in acinic cells and pancreatic duct; meanwhile endocrine cells showed very weak expression (4x-10x).
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fig3
Immunohistochemical staining for insulin showed strongly positive Beta cells of the islets of Langerhans within the ectopic pancreatic tissue (Figure 3).