Prognostic false-positivity of the sentinel node in melanoma

Abstract

It is a basic tenet of the sentinel lymph-node biopsy procedure that all positive sentinel lymph nodes will inevitably progress to palpable nodal recurrence if not removed. Comparison of survival is, therefore, considered permissible among patients with positive sentinel lymph nodes who undergo early lymphadenectomy with that among patients who have delayed lymphadenectomy for palpable regional node metastasis, providing that survival is calculated from the date of wide local excision of the primary tumor. Here, that fundamental assumption is contested and evidence is presented to show that a positive sentinel lymph node might have no adverse prognostic relevance in up to one-third of patients. Furthermore, in the same patients, progression to palpable nodal disease might not have occurred even if the positive sentinel node had not been removed. The term prognostic false-positivity is used to describe this phenomenon. Such patients are incorrectly up-staged, are given inaccurate prognostic information and can undergo unnecessary completion lymphadenectomy and unnecessary adjuvant therapy.

SPECT/CT for sentinel lymph node mapping in head and neck melanoma

“…SPECT/CT visualized a mean of 2.6 sentinel nodes per patient (range, [1][2][3][4][5][6]. SPECT/CT depicted an additional sentinel node in 16% of the patients and clearly showed the anatomic location of the hot nodes in all patients.…”

“…1 Patients with melanoma are offered a sentinel node biopsy in many centers, although the therapeutic consequences that should follow the finding of a positive sentinel node are a subject of discussion. 2,3 Sentinel node biopsy in the head and neck is often more difficult than in other nodal basins, due to the complex anatomy and the variable drainage patterns in this region. [4][5][6][7] Elsewhere in the body, patent blue is used in addition to a radiotracer to visualize the lymphatic channel that leads to the sentinel nodes.…”

Lack of significance of sentinel lymph node biopsy for the prognosis and management of the atypical Spitz tumor of uncertain biologic potential

“…The evidence that this may be the case in AST is far less robust although DNA copy number aberrations (including loss of the p16 tumor-suppressor gene locus) have been reported in ASTs [9][10][11]. This paucity of evidence is, in the most part, likely to be due to the rarity of these lesions and the considerable ambiguity concerning their diagnosis.…”

Lymph node assessment in melanoma

“…He also found more positive nodes at lymphadenectomy in the observation arm (3.3 AE 0.5) compared to the SLNB arm (1.4 AE 0.1) suggesting that allowing the nodal disease to progress may have contributed to poorer survival. A number of authors have disputed the significance of these findings [31][32][33]. Patients who developed nodal metastases after negative SLNB were not included in the survival analysis of the node positive patients, as they should have been by intention to treat analysis.…”