RT Journal Article SR Electronic T1 Caval foramen hernia masquerading as a thoracic mass JF Canadian Journal of Surgery JO CAN J SURG FD Canadian Medical Association SP 64 OP 65 VO 49 IS 1 A1 Calvin S.H. Ng A1 Tak Wai Lee A1 Song Wan A1 Anthony P.C. Yim YR 2006 UL http://canjsurg.ca/content/49/1/64.abstract