False-negative sentinel node biopsy because of obstruction of lymphatics by metastatic melanoma: the value of ultrasound in conjunction with preoperative lymphoscintigraphy

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.

Preoperative Ultrasound is Not Useful for Identifying Nodal Metastasis in Melanoma Patients Undergoing Sentinel Node Biopsy: Preoperative Ultrasound in Clinically Node-Negative Melanoma

“…Preoperative ultrasound may detect abnormal lymph nodes which could not be localized via lymphoscintigraphy when lymphatic obstruction is present. [32] The false-negative rate for SLNB is not insignificant, with reports ranging from 1.5 to 21% depending on calculation method. [33, 34] Our false negative rate calculated by [false negative/ (false negative + true positive)] × 100% was 10.4%.…”

Analysis of Melanoma Recurrence Following a Negative Sentinel Lymph Node Biopsy

“…Among patients with head and neck melanoma, perhaps 55% of patients with melanoma-specific deaths developed metastatic disease without evidence of nodal involvement, suggesting a more direct hematogenous Melanoma recurrence after a negative sentinel node biopsy SyStematic Review future science group www.futuremedicine.com spread of the disease [7,12]. Similarly, metastatic melanoma leading to obstruction of lymphatic drainage has been proposed as a possible etiology of metastatic disease following a negative SLNBx, with case studies describing obstruction of lymphatic channels leading to failed lymphoscintigraphy, requiring ultrasound to diagnose the presence of metastatic nodal disease [34,35]. Management of distant or recurrent disease may be altered by clarifying the mechanism of melanoma metastasis.…”

Indocyanine Green SPY Elite–Assisted Sentinel Lymph Node Biopsy in Cutaneous Melanoma

“…6,9,10 In addition, the biological nature of cutaneous melanoma is characterized by slow dissemination of metastatic cells in lymphatic channels or large tumor deposits blocking or diverting lymphatic drainage, both of which can contribute to false-negative sentinel lymph node biopsy. 11,12 Furthermore, nonlocalization of sentinel lymph nodes is noted in up to 5 percent of cases.…”