AIM To clarify clinicopathological features of ductal carcinoma in situ(DCIS) visualized on [F-18] fluorodeoxyglucosepositron emission tomography/computed tomography(FDG-PET/CT).METHODS This study retrospectively reviewed 52 consecutive tumors in 50 patients with pathologically proven pure DCIS who underwent [F-18] FDG-PET/CT before surgery. [F-18] FDG-PET/CT was performed after biopsy in all patients. The mean interval from biopsy to [F-18] FDGPET/CT was 29.2 d. [F-18] FDG uptake by visual analysis and maximum standardized uptake value(SUVmax) was compared with clinicopathological characteristics.RESULTS[F-18] FDG uptake was visualized in 28 lesions(53.8%) and the mean and standard deviation of SUVmax was 1.63 and 0.90. On univariate analysis, visual analysis and the SUVmax were associated with symptomatic presentation(P = 0.012 and 0.002, respectively), palpability(P = 0.030 and 0.024, respectively), use of core-needle biopsy(CNB)(P = 0.023 and 0.012, respectively), ultrasound-guided biopsy(P = 0.040 and 0.006, respectively), enhancing lesion ≥ 20 mm on magnetic resonance imaging(MRI)(P = 0.001 and 0.010, respectively), tumor size ≥ 20 mm on histopathology(P = 0.002 and 0.008, respectively). However, [F-18] FDG uptake parameters were not significantly associated with age, presence of calcification on mammography, mass formation on MRI, presence of comedo necrosis, hormone status(estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2), and nuclear grade. The factors significantly associated with visual analysis and SUVmax were symptomatic presentation(P = 0.019 and 0.001, respectively), use of CNB(P = 0.001 and 0.031, respectively), and enhancing lesion ≥ 20 mm on MRI(P = 0.001 and 0.049, respectively) on multivariate analysis.CONCLUSION Although DCIS of breast is generally non-avid tumor, symptomatic and large tumors(≥ 20 mm) tend to be visualized on [F-18] FDG-PET/CT. AIM To clarify clinicopathological features of ductal carcinoma in situ (DCIS) visualized on [F-18] fluorodeoxyglucosepositron emission tomography / computed tomography (FDG-PET / CT) .METHODS This study retrospectively reviewed 52 consecutive tumors in 50 patients with pathologically proven pure DCIS who underwent [F-18] FDG-PET / CT before surgery. [F-18] FDG-PET / CT was performed after biopsy in all patients. . F-18 FDG uptake by visual analysis and maximum standardized uptake value (SUVmax) was compared with clinicopathological characteristics .RESULTS [F-18] FDG uptake was visualized in 28 lesions (53.8%) and the mean and standard deviation of SUVmax were 1.63 and 0.90 respectively. On univariate analysis, visual analysis and the SUVmax were associated with symptomatic presentation (P = 0.012 and 0.002 respectively), palpability (P = 0.030 and 0.024, respectively), use of core-needle biopsy P = 0.023 and 0.012, respectively), ultrasound-guided Biopsy (P = 0.040 and 0.006, respectively), enhancing lesion ≥ 20 mm on magnetic resonance imaging (MRI) (P = 0.001 and 0.010, respectively), tumor size ≥ 20 mm on histopathology (P = 0.002 and 0.008, respectively). However, [F-18] FDG uptake parameters were not significantly associated with age, presence of calcification on mammography, mass formation on MRI, presence of comedo necrosis, hormone status (estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2) , and nuclear grade. The factors significantly associated with visual analysis and SUVmax were symptomatic presentation (P = 0.019 and 0.001, respectively), use of CNB (P = 0.001 and 0.031, respectively), and enhancing lesion ≥ 20 mm on MRI = 0.001 and 0.049, respectively) on multivariate analysis. CONCLUSION Although DCIS of breast is generally non-avid tumor, symptomatic and large tumors (≥ 20 mm) tend to be visualized on [F-18] FDG-PET / CT.