PMC5686469_01
18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT).. (a) First detected mediastinal lymph nodes. (b) 3 months later, CT scan showed that the size of mediastinal lymph nodes was almost unchanged. (c) 6 months later, the size and the maximum standardized uptake value (SUVmax) of mediastinal lymph nodes had increased.
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The serum carcinoembryonic antigen (CEA) level (1.1 ng/ml) was within the normal range. 18F-fluorodeoxyglucose (FDG) positron emission tomography showed that FDG was accumulated only into the mediastinal lymph nodes. (Fig. 1a). Three months later, CT scan showed the size of the mediastinal lymph nodes was almost unchanged (Fig. 1b). However, six months later, FDG-PET/CT scan showed the size and SUVmax of the mediastinal lymph nodes had increased to 33 mm and 9.88, respectively (Fig. 1c).
Intraoperative finding.. (a) Thoracoscopic image in the left lateral decubitus position. Tumor(arrows).. (b) Schema of (a).
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Due to the time-course change over the previous 6 months, we suspected that the mediastinal lymph nodes were metastasized from the ascending colon cancer and so performed thoracoscopic-assisted resection of the mediastinal lymph nodes (Fig. 2a and b).
Histopathological findings of resected specimen.. (a) Resected specimen. (b) Lymph nodes were filled with moderately differentiated adenocarcinoma in cribriform pattern. H&E, x40, scale bar: 500 mum. An insert shows a higher magnification of the boxed area.
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Macroscopic findings of the resected specimen showed a cluster of three solid masses, measuring 85 x 35 x 30 mm in size (Fig. 3a). Histopathological analysis revealed that the lymph nodes were filled with moderately differentiated adenocarcinoma in a cribriform pattern (Fig. 3b), which was completely consistent with the histopathological features of the primary colon cancer.
Computed tomography at both preoperation and 1 year and 4 months after operation.. (a) Mediastinal lymph nodes at preoperation(yellow circle). (b) 1 year and 4 months later, there was no evidence of recurrence.
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The patient has been followed for more than 1 years and 8 months without any signs of recurrence (Fig. 4a and b).