ORIGINAL ARTICLES: Clinical researchFalse-negative sentinel node biopsy because of obstruction of lymphatics by metastatic melanoma: the value of ultrasound in conjunction with preoperative lymphoscintigraphyLam, Tai K.a; Uren, Roger F.a c; Scolyer, Richard A.a b e; Quinn, Michael J.a; Shannon, Kerwin F.a d; Thompson, John F.a fAuthor Information aMelanoma Institute Australia, incorporating the Sydney Melanoma Unit bDepartment of Anatomical Pathology, Royal Prince Alfred Hospital, Camperdown cNuclear Medicine and Diagnostic Ultrasound, RPAH Medical Centre, Newtown Disciplines of dSurgery ePathology fSurgery, Faculty of Medicine, The University of Sydney, Sydney, New South Wales, Australia Correspondence to Professor John F. Thompson, MD, FRACS, FACS, Sydney Melanoma Unit, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia Tel: +61 2 9911 7366; fax: +61 2 9954 9435; e-mail: [email protected] Received 1 August 2008 Accepted 30 October 2008 Melanoma Research: April 2009 - Volume 19 - Issue 2 - p 94-99 doi: 10.1097/CMR.0b013e32832166b7 Buy Metrics Abstract The aim of this study was to describe how metastatic melanoma obstructing lymphatic flow to sentinel nodes can result in a false-negative sentinel node biopsy and to show that the use of ultrasound in conjunction with preoperative lymphoscintigraphy can avoid this potential diagnostic pitfall. A series of three patients in whom metastatic melanoma obstructed lymphatic flow to sentinel nodes is reported. In these patients, lymphoscintigraphy failed to identify nodes containing metastatic disease. This resulted in a false-negative sentinel node biopsy result in two patients. A sentinel node biopsy was not carried out in the third patient, but the same dilemma was encountered. These cases provide further insights into the dynamics of lymphatic flow and suggest possible reasons for occasional inaccuracy of sentinel node biopsy. They also highlight the advantages of using ultrasound to assess lymph nodes in any node fields to which lymphatic drainage occurs from a primary tumour site. © 2009 Lippincott Williams & Wilkins, Inc.