PMC5228670_01
View of colonoscope: a hyperemic and fragile mass without pedicle, covered with some sphacelus, 1.2cm x 1.5 cm size, protruded from rectal mucosa, 10 cm distant from anus.
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F1
The electronic colonoscope examination showed a hyperemic mass covered with sphacelus, approximately 1.2 cm x 1.5 cm size, which was protruded from rectal mucosa (Fig. 1).
Micrograph of the biopsy specimen and immunohistochemical examination results. (A) HE staining image, x150. (B) HE staining image, x300. (C): AE1/AE3 (+), x150. (D) PAX-8(+), x150. (E) Vimentin (+), x150. (F) CDX-2(-), x150. (G) Melan-A (-), x150. (H) alpha-inhibin (-), x150.
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F2
Under the microscope, there were amounts of large and anomalously shaped clear cells with abundant clear cytoplasm and nuclear atypia consistent with RCCC, forming nests or aciniform structure surrounded with slender small vascular tissues (Fig. 2). Immunohistochemical examination revealed cytokeratin pan (AE1/AE3) (+), paired box (PAX)-8 (+), Vimentin (+), caudal typehomebox transcription factor (CDX)-2 (-), Melan-A (-), and alpha-inhibin (-) (Fig. 2).
Axial view of FDG-PET/CT: hypermetabolic activity in upper rectum with average SUV of 5.0 and SUVmax of 10.0, 1.6 cm x 2.8 cm x 1.8 cm sizes.
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F3
Positron emission tomography-computed tomography with fluorodeoxyglucose (FDG-PET/CT) examination was performed, which showed an abnormal increased radioactive uptake in the upper rectum, 1.6 cm x 2.8 cm x 1.8 cm size, with an average standardized uptake value (SUV) of 5.0 and SUVmax of 10.0, indicating possibility of malignancy (Figs. 3 and 4).
Sagittal view of FDG-PET/CT: abnormal increased radioactive uptake in the upper rectum.
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F4
Positron emission tomography-computed tomography with fluorodeoxyglucose (FDG-PET/CT) examination was performed, which showed an abnormal increased radioactive uptake in the upper rectum, 1.6 cm x 2.8 cm x 1.8 cm size, with an average standardized uptake value (SUV) of 5.0 and SUVmax of 10.0, indicating possibility of malignancy (Figs. 3 and 4).