title: Assessment of the role of sentinel lymph node biopsy for primary cutaneous desmoplastic melanoma.
abstract: BACKGROUND
  The role of sentinel lymph node biopsy (SLNB) in the treatment of desmoplastic melanoma (DM) remains undefined. The purpose of this study was to evaluate the use of SLNB for DM.
  
  
  METHODS
  In all, 1850 patients with cutaneous melanoma underwent wide local excision and SLNB. Patients with DM were identified and stratified as 'pure' DM or 'mixed' DM (i.e., DM associated with at least one other common histologic subtype).
  
  
  RESULTS
  Of the 1850 patients, 65 (3.5%) had DM. Of these, 46 (70.8%) had pure DM and 19 (29.2%) had mixed DM. Patients with pure DM had a median tumor thickness of 3.5 mm and 6.5% were ulcerated. Compared with patients with pure DM, patients with either mixed DM or non-DM (n = 1785) had thinner primary tumors (median, 1.7 mm and 1.5 mm, respectively, each P < 0.001 vs. pure DM) that were more likely to be ulcerated (27.7% and 21.3%, respectively, each P < 0.05 vs. pure DM). Although the incidence of a positive SLN was similar in patients with mixed DM (15.8%) and non-DM (17.5%), patients with pure DM were less likely to have a positive SLN (2.2%) (each P < 0.01 vs. non-DM and mixed DM). At a median follow-up of 2.9 years, no patient with pure DM had recurred.
  
  
  CONCLUSIONS
  Despite having thicker primary tumors, patients with pure DM have a lower incidence of positive SLNs compared with patients with non-DM. Whereas the treatment approach for patients with mixed DM should be similar to that of other melanoma patients, patients with pure DM are unlikely to have metastatic disease in regional lymph nodes and SLNB may not be warranted.
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, 77230, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
authors.forename: Merrick I
authors.initials: MI
authors.lastname: Ross
authors.forename: Victor G
authors.initials: VG
authors.lastname: Prieto
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Ballo
authors.forename: Marcella M
authors.initials: MM
authors.lastname: Johnson
authors.forename: Paul F
authors.initials: PF
authors.lastname: Mansfield
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Lee
authors.forename: Janice N
authors.initials: JN
authors.lastname: Cormier
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Gershenwald
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008297:Male; D008545:Melanoma / Q000473:pathology* / Q000628:therapy; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D010347:Patient Care Planning; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000473:pathology* / Q000628:therapy; D012883:Skin Ulcer / Q000209:etiology / Q000473:pathology