title: Management of popliteal sentinel nodes in melanoma.
abstract: BACKGROUND
  Although most melanomas on the distal lower extremity drain exclusively to inguinal lymph nodes, a small percentage (<5%) drain to interval nodes in the popliteal basin. We investigated a possible relationship between tumor-draining popliteal and inguinal nodes in patients with lower-extremity melanoma.
  
  
  METHODS
  We queried our melanoma database to identify patients who underwent sentinel node biopsy (SNB) for an infrapopliteal melanoma. Patterns of nodal drainage and nodal metastasis were analyzed.
  
  
  RESULTS
  Of 461 patients who underwent SNB for a primary infrapopliteal melanoma, 15 (3.2%) had drainage to the popliteal basin. Thirteen melanomas were on the posterior leg and foot, and 2 were on the anterior lower leg. Mean Breslow thickness was 2.4 mm. All 15 patients with popliteal drainage also had inguinal drainage and therefore underwent concurrent inguinal and popliteal SNB. The average number of popliteal sentinel nodes was 1.4 (range 1 to 3). Eight patients (53%) had a tumor-positive popliteal sentinel node, and 6 of the 8 underwent completion popliteal lymphadenectomy. Four of the 8 patients (50%) also had tumor-positive inguinal sentinel nodes; all underwent complete inguinal lymphadenectomy. We also identified 9 additional patients who underwent SNB for locoregional recurrent melanomas of the infrapopliteal leg. Three (33%) of these patients had concurrent inguinal and popliteal SNB, with 1 isolated tumor-positive popliteal node found.
  
  
  CONCLUSIONS
  In our series, a high percentage of popliteal sentinel lymph nodes contained metastases, and these patients frequently also had inguinal metastases. In our patients, all inguinal metastases were associated with concomitant popliteal metastases. Although it is anatomically separate, the inguinal basin appears to be a functional extension of the popliteal basin.
authors: John Wayne Cancer Institute at Saint John's Health Center, Santa Monica, CA, USA.
authors: Shawn T
authors: ST
authors: Steen
authors: Hamed
authors: H
authors: Kargozaran
authors: Christopher J
authors: CJ
authors: Moran
authors: Myung
authors: M
authors: Shin-Sim
authors: Donald L
authors: DL
authors: Morton
authors: Mark B
authors: MB
authors: Faries
mesh_terms: D000328:Adult; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007264:Inguinal Canal; D007866:Leg; D008297:Male; D008545:Melanoma / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D008875:Middle Aged; D009367:Neoplasm Staging; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D055815:Young Adult