A 36-year-old male patient with no remarkable medical history was admitted to our hospital for a health check up. On chest radiography, bilateral aortic notches at the level of aortic arch were shown suggesting aortic arch anomaly without any clinical symptoms. Two aortic arches were almost same-in-size on suprasternal view of transthoracic echocardiography. In addition, multidetector computed tomography showed balanced type double aortic arch forming a complete vascular ring which encircled the trachea and esophagus. The trachea was slightly compressed by the vascular ring whereas the esophagus was intact. Nevertheless, the pulmonary function test was normal. The patient was discharged from hospital with instructions for periodic follow-up.

Urethral metastasis from colorectal cancer is rare and is known to have a poor prognosis. A 72-year-old man with a history of colectomy and colostomy due to sigmoid colon cancer was admitted to the emergency room with bowel distension, rectal bleeding and urinary symptoms. Computed tomography of the abdominopelvis showed sigmoid colon cancer with multiple metastases involving the liver. Positron emission tomography with F-18 fluorodeoxyglucose (FDG) showed multiple hypermetabolic foci in the liver, penis and pubic bone, which otherwise could not be diagnosed. The lesions revealed no improvement with chemotherapy and urological surgery on follow-up F-18 FDG PET/CT. We present a case of urethral metastasis of sigmoid colon cancer diagnostically and prognostically indicated by F-18 FDG PET/CT.

Due to the low yield of AFB smear and culture in extrapulmonary tuberculosis, therapeutic responses of patients with extrapulmonary tuberculosis are usually monitored clinically and/or radiographically. Such monitoring techniques, however, are not enough to provide effective diagnosis if a remnant lesion exists after treatment. Tuberculosis presents hypermetabolic activity on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) scanning. Reported herein is a case of extrapulmonary tuberculosis where the therapeutic response was assessed via serial F-18 FDG PET/CT scanning, which was useful for detecting the extent of extrapulmonary tuberculosis and for estimating the patient's therapeutic response.