The Role of Interval Nodes in Sentinel Lymph Node Mapping and Dissection for Melanoma Patients
Maurice Matter 1*,
Marie Nicod Lalonde 2,
Mohamed Allaoua 2,
Ariane Boubaker 2,
Danielle Liénard 3,
Oliver Gugerli 4,
Jean-Philippe Cerottini 5,
Hanifa Bouzourene 6,
Angelika Bischof Delaloye 2,
and
Ferdinand Lejeune 7
1 Department of Visceral Surgery, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
2 Department of Nuclear Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
3 Department of Oncology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
4 Department of Pathology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Department of Dermatology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
5 Department of Dermatology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
6 Department of Pathology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
7 Department of Visceral Surgery, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Department of Oncology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
* To whom correspondence should be addressed. E-mail: maurice.matter{at}chuv.ch.
 |
Abstract |
|---|
In sentinel node (SN) biopsy, an interval SN is defined as a lymph node or group of lymph nodes located between the primary melanoma and an anatomically well-defined lymph node group directly draining the skin. As shown in previous reports, these interval SNs seem to be at the same metastatic risk as are SNs in the usual, classic areas. This study aimed to review the incidence, lymphatic anatomy, and metastatic risk of interval SNs. Methods: SN biopsy was performed at a tertiary center by a single surgical team on a cohort of 402 consecutive patients with primary melanoma. The triple technique of localization was used—that is, lymphoscintigraphy, blue dye, and 
-probe. Otolaryngologic melanoma and mucosal melanoma were excluded from this analysis. SNs were examined by serial sectioning and immunohistochemistry. All patients with metastatic SNs were recommended to undergo a radical selective lymph node dissection. Results: The primary locations of the melanomas included the trunk (188), an upper limb (67), or a lower limb (147). Overall, 97 (24.1%) of the 402 SNs were metastatic. Interval SNs were observed in 18 patients, in all but 2 of whom classic SNs were also found. The location of the primary was truncal in 11 (61%) of the 18, upper limb in 5, and lower limb in 2. One patient with a dorsal melanoma had drainage exclusively in a cervicoscapular area that was shown on removal to contain not lymph node tissue but only a blue lymph channel without tumor cells. Apart from the interval SN, 13 patients had 1 classic SN area and 3 patients 2 classic SN areas. Of the 18 patients, 2 had at least 1 metastatic interval SN and 2 had a classic SN that was metastatic; overall, 4 (22.2%) of 18 patients were node-positive. Conclusion: We found that 2 of 18 interval SNs were metastatic: This study showed that preoperative lymphoscintigraphy must review all known lymphatic areas in order to exclude an interval SN.
Key Words:
melanoma, sentinel lymph node dissection, interval node
