The sentinel lymph node (SLN) is the first node in a nodal basin to receive the direct lymphatic flow from a malignant melanoma. However, in some patients, lymphoscintigraphic study reveals the presence of lymphatic nodes in the area between the primary melanoma and the regional basin. These nodes are called “in-transit nodes” or “interval nodes” and, by definition, are also SLNs. The purpose of this study was to determine the incidence and location of in-transit SLNs in patients with malignant melanoma and to assess whether it is really necessary to harvest them. The evaluation involved 600 consecutive malignant melanoma patients. Lymphoscintigraphy was performed on the day before surgery following intradermal injection of 74–111 MBq of 99mTc-nanocolloid in four doses around the primary melanoma or the biopsy scar. Dynamic and static images were obtained and revealed SLNs in 599 out of 600 patients. The SLN was intraoperatively identified with the aid of patent blue dye and a hand-held gamma probe. Lymphoscintigraphy showed in-transit SLNs in 59/599 patients (9.8%). During surgery, all these in-transit SLNs were harvested, with those in the popliteal and epitrochlear regions being the most difficult to identify and excise. Metastatic cell deposits were subsequently identified in ten (16.9%) of these in-transit SLNs. In conclusion, lymphoscintigraphy has a key role in the identification of in-transit SLNs. Although the incidence of these nodes is relatively low in malignant melanoma patients, such SLNs present metastatic deposits in a significant percentage of cases and therefore the identification of in-transit SLNs in these patients is really necessary.
This is a preview of subscription content, log in to check access.
This work was supported in part by grants from Fondo de Investigaciones Sanitarias (FIS 1023/00) and Instituto de Salud Carlos III, Red Temática del Cáncer no. C03/10.
Reintgen D, Cruse WC, Wells K, et al. The orderly progression of melanoma nodal metastases. Ann Surg 1994; 220:759–767.Google Scholar
Valdés-Olmos RA, Jansen L, Muller SH, Hoefnagel CA, Nieweg O. Contribution of nuclear medicine to lymphatic mapping and sentinel node identification in oncology. Rev Esp Med Nucl 1999; 18:111–121.PubMedGoogle Scholar
Morton DL, Thompson JF, Essner R, et al. Validation of the accuracy of intraoperative lymphatic mapping and sentinel lymphadenectomy for early-stage melanoma. A multicenter trial. Ann Surg 1999; 230:453–465.PubMedGoogle Scholar
Jacobs IA, Chevinsky AH, Swayne LC, Magidson JG, Britto EJ, Smith TJ. Gamma-probe directed lymphatic mapping and sentinel lymphadenectomy in primary melanoma: readability of the procedure and analysis of failures after long-term follow-up. J Surg Oncol 2001; 77:157–164.CrossRefPubMedGoogle Scholar
Vidal-Sicart S, Pons F, Puig S, et al. Identification of the sentinel lymph node in patients with malignant melanoma: what are the reasons for mistakes? Eur J Nucl Med Mol Imaging 2003; 30:362–366.PubMedGoogle Scholar
Morton DL, Wen D, Wong JH, et al. Technical details of intraoperative lymphatic mapping for early stage melanoma. Arch Surg 1992; 127:392–399.PubMedGoogle Scholar
Norman J, Cruse W, Espinosa C, et al. Redefinition of cutaneous lymphatic drainage with the use of lymphoscintigraphy for malignant melanoma. Am J Surg 1991; 162:432–437.PubMedGoogle Scholar
Statius Muller MG, Hennipman FA, van Leeuwen PAM, Pijpers R, Vuylsteke RJCLM, Meijer S. Unpredictability of lymphatic drainage patterns in melanoma patients. Eur J Nucl Med Mol Imaging 2002; 29:255–261.CrossRefPubMedGoogle Scholar
Uren RF, Howman-Giles RB, Shaw HM, Thompson JF, McCarthy WH. Lymphoscintigraphy in high-risk melanoma of the trunk: predicting draining node groups, defining lymphatic channels and locating the sentinel node. J Nucl Med 1993; 34:1435–1440.PubMedGoogle Scholar
O’Brien CJ, Uren RF, Thompson JF, et al. Prediction of potential metastatic sites in cutaneous head and neck melanoma using lymphoscintigraphy. Am J Surg 1995; 170:461–466.CrossRefPubMedGoogle Scholar
Vidal-Sicart S, Pons F, Piulachs J, Castel T, Palou J, Herranz R. Mid-arm sentinel lymph nodes showing surprising drainage from a malignant melanoma in the forearm. Clin Nucl Med 1998; 23:273–274.Google Scholar
Hunt JA, Thompson JF, Uren RF, Howman-Riles R, Harman CR. Epitrochlear lymph nodes as a site of melanoma metastasis. Ann Surg Oncol 1998; 5:248–252.PubMedGoogle Scholar