Background: The sentinel lymph node (SLN) is the first lymph node in the re
gional nodal basin to receive metastatic cells. In-transit nodes are found
between the primary melanoma site and regional nodal basins. To date, this
is one of the first reports on micrometastasis to in-transit nodes.
Methods: Retrospective database and medical records were reviewed from Octo
ber 21, 1993, to November 19, 1999. At the UCSF Melanoma Center, patients w
ith tumor thickness >1 min or <1 mm with high-risk features are managed wit
h preoperative lymphoscintigraphy, selective SLN dissection, and wide local
excision.
Results: Thirty (5%) out of 557 extremity and truncal melanoma patients had
in-transit SLNs, Three patients had positive in-transit SLs, and negative
SLNs in the regional nodal basin. Two patients had positive in-transit and
regional SLNs. Three patients had negative in-transit SLNs but positive reg
ional SLNs. The remaining 22 patients were negative for in-transit and regi
onal SLNs.
Conclusions: In-transit SLNs may harbor micrometastasis. About 10% of the t
ime, micrometastasis may involve the in-transit and not the regional SLN. T
herefore, both in-transit and regional SLNs should be harvested.