title: Tumefactive Gallbladder Sludge at US: Prevalence and Clinical Importance.
abstract: Purpose To evaluate the prevalence of tumefactive sludge of the gallbladder detected at ultrasonography (US) and to assess whether any clinical and imaging differences exist between benign and malignant tumefactive sludge. Materials and Methods The institutional review board approved this retrospective study. The requirement for informed consent was waived. The study included a cohort (n = 6898) of patients with gallbladder sludge drawn from all adults (n = 115 178) who underwent abdominal US between March 2001 and March 2015. Tumefactive sludge was identified according to the following US findings: (a) nonmovable mass-like lesion and (b) absence of posterior acoustic shadowing at B-mode US and vascularity at color Doppler US. Follow-up examinations were arranged to ascertain whether the results showed true sludge or gallbladder cancer. Risk factors for malignant tumefactive sludge based on clinical and US characteristics were identified with multivariate logistic regression analysis. Results The prevalence of gallbladder and tumefactive sludge at abdominal US during the observation period was 6.0% (6898 of 115 178) and 0.1% (135 of 115 178), respectively. Twenty-eight (20.7%) patients were lost to follow-up. Of the 107 with tumefactive sludge, 15 (14%) were confirmed to have malignant tumefactive sludge. The risk factors for malignant tumefactive sludge were old age (odds ratio [OR], 1.06; P = .035), female sex (OR, 5.48; P = .014), and absence of hyperechoic spots within the sludge (OR, 6.78; P = .008). Conclusion Although the prevalence of tumefactive sludge at US was rare, a considerable proportion of patients had a malignancy. Careful follow-up is essential, especially for older patients, women, and those with an absence of hyperechoic spots at US.©RSNA, 2016 Online supplemental material is available for this article.
authors.affiliation: From the Departments of Radiology (M.K., T.W.K., K.M.J., Y.K.K., S.H.K.), Pathology (S.Y.H.), and Internal Medicine (D.H.S.) and the Biostatics and Clinical Epidemiology Center (S.G.), Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
authors.forename: Mimi
authors.initials: M
authors.lastname: Kim
authors.affiliation: From the Departments of Radiology (M.K., T.W.K., K.M.J., Y.K.K., S.H.K.), Pathology (S.Y.H.), and Internal Medicine (D.H.S.) and the Biostatics and Clinical Epidemiology Center (S.G.), Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
authors.forename: Tae Wook
authors.initials: TW
authors.lastname: Kang
authors.affiliation: From the Departments of Radiology (M.K., T.W.K., K.M.J., Y.K.K., S.H.K.), Pathology (S.Y.H.), and Internal Medicine (D.H.S.) and the Biostatics and Clinical Epidemiology Center (S.G.), Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
authors.forename: Kyung Mi
authors.initials: KM
authors.lastname: Jang
authors.affiliation: From the Departments of Radiology (M.K., T.W.K., K.M.J., Y.K.K., S.H.K.), Pathology (S.Y.H.), and Internal Medicine (D.H.S.) and the Biostatics and Clinical Epidemiology Center (S.G.), Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
authors.forename: Young Kon
authors.initials: YK
authors.lastname: Kim
authors.affiliation: From the Departments of Radiology (M.K., T.W.K., K.M.J., Y.K.K., S.H.K.), Pathology (S.Y.H.), and Internal Medicine (D.H.S.) and the Biostatics and Clinical Epidemiology Center (S.G.), Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
authors.forename: Seong Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: From the Departments of Radiology (M.K., T.W.K., K.M.J., Y.K.K., S.H.K.), Pathology (S.Y.H.), and Internal Medicine (D.H.S.) and the Biostatics and Clinical Epidemiology Center (S.G.), Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
authors.forename: Sang Yun
authors.initials: SY
authors.lastname: Ha
authors.affiliation: From the Departments of Radiology (M.K., T.W.K., K.M.J., Y.K.K., S.H.K.), Pathology (S.Y.H.), and Internal Medicine (D.H.S.) and the Biostatics and Clinical Epidemiology Center (S.G.), Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Sinn
authors.affiliation: From the Departments of Radiology (M.K., T.W.K., K.M.J., Y.K.K., S.H.K.), Pathology (S.Y.H.), and Internal Medicine (D.H.S.) and the Biostatics and Clinical Epidemiology Center (S.G.), Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-Dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
authors.forename: Seonhye
authors.initials: S
authors.lastname: Gu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001646:Bile / Q000000981:diagnostic imaging*; D005260:Female; D005705:Gallbladder Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods* / Q000706:statistics & numerical data*