Interval sentinel lymph nodes: an unusual localization in patients with cutaneous melanoma

Subcostal lymph nodes: An unusual sentinel lymph node basin in cutaneous melanoma

BACKGROUND AND OBJECTIVES

Lymphatic drainage from subcostal nodes, along the costal groove, have not previously been characterized as sites for melanoma drainage and metastasis. This study reports a series of patients with subcostal nodes draining primary melanomas, with characterization of the sites of primary melanomas that drain to these nodes.

METHODS

Patients who presented to our institution between 2005 and 2020 with documented cutaneous melanoma and sentinel lymph node biopsy of a subcostal node (sentinel = S), or metastases to subcostal nodes later in clinical management (recurrent = R) were included. Patient demographics, melanoma pathology, nodal features, imaging information, surgical approaches, and outcomes data were collected.

RESULTS

Six patients had subcostal sentinel nodes (SNs). Primary sites included the posterior trunk and lateral chest wall. Subcostal nodes were found under ribs 10-12. Subcostal SNs had at least one dimension measuring 3 mm or less. There were no surgical complications related to removing the subcostal SN.

CONCLUSIONS

Melanoma can metastasize to subcostal lymph nodes and be found at the time of SN biopsy or identified at recurrence. These small nodes are fed by lymphatic channels that run in the neurovascular bundle under the ribs. When lymphatic mapping identifies a subcostal SN, it should be excised.

In transit sentinel node drainage as a prognostic factor for patients with cutaneous melanoma

BACKGROUND

Minor basin or in transit node drainage can be found in patients with cutaneous melanoma who undergo sentinel node biopsy. Its clinical impact is still unclear. Our objective is to evaluate clinical outcomes in patients who presented with in transit sentinel node (ITN) drainage.

MATERIAL AND METHODS

Retrospective analysis of patients who underwent sentinel node biopsy (SNB) in a single Brazilian institution between 2000 and 2015.

RESULTS

Our cohort comprised 1223 SNB. There were 64 patients (5.2%) with ITN. Melanoma of the limbs (OR 10.61, P < 0.0001) and acral subtype (OR 3.49, P < 0.0001) were associated with ITN drainage. Among these 64 patients, 14 (21.9%) had a positive SNB. The ITN was positive for metastases in five patients, four in a popliteal basin and one on the trunk. Regarding completion node dissection (CND), two patients had positive non-sentinel nodes (NSN), both in major basins. In patients who developed recurrence, time to recurrence was shorter (mean time 18 vs 31.4 months, P = 0.001) and time to death was shorter (mean time 31.6 vs 40 months, P = 0.039) in those who had ITN drainage.

CONCLUSION

ITN drainage was associated with earlier recurrences and deaths from melanoma.

Patterns of node mapping differ for axial and extremity primary cutaneous melanoma: A case for a more selective use of pre-operative imaging

PURPOSE

Preoperative lymphoscintigraphy for sentinel lymph node mapping in melanoma improves the ability to locate nodes. However, it still remains unclear whether this step is required for all patients.

METHODS

Patients diagnosed with cutaneous melanoma from 1996 to 2012 were identified. Exclusion criteria were in situ disease, metastatic disease, or no SLN biopsy.

RESULTS

214 patients were evaluated. Median age was 57 years, the majority were male (59.8%), white (97.2%), and stage I (60.7%). SLN revealed metastatic disease in 14.5% of patients. The most common primary site was the trunk (43.4%) followed by head and neck (21%), upper extremity (19.2%), and lower extremity (16.4%). Multiple lymphatic basins were most common for head and neck lesions (66.7%) followed by those on the trunk (28.8%), with fewer identified when lower (11.4%), and upper extremities were involved (4.2%). When comparison was restricted to extremity vs. axial, a single basin was noted in 94.5% vs. 59.9% of patients, p < 0.0001. For all extremity lesions the SLN was located in the primary basin. Additional sites included in-transit (popliteal) and second tier basins. The only melanomas with bilateral or contralateral SLN were axial melanomas.

CONCLUSIONS

Patients with axial melanomas benefit most from lymphoscintigraphy. This step may not be required for extremity melanoma.