Desmoplastic neurotropic melanoma: a clinicopathologic analysis of 128 cases.
BACKGROUND
Several studies have suggested that desmoplastic neurotropic melanoma (DNM) is associated with higher local recurrence rates than other types of melanoma. The authors investigated the local recurrence rates for patients with DNM after surgery alone or surgery followed by radiotherapy (RT).


METHODS
One hundred twenty-eight patients with DNM were treated at the Sydney Melanoma Unit and the Sydney Cancer Center from 1996 to 2007. All patients underwent local excision, 27 patients also received RT. For both groups, clinical and pathologic features, treatment details, and local recurrence data were analyzed.


RESULTS
The median age at diagnosis was 65.5 years. The ratio of men to women was 2.7:1. The head and neck was the most common location (51%). The median Breslow thickness was 4 mm, and 99% of patients had Clark Level IV or V primary tumors. Patients who received adjuvant RT had thicker tumors (P = .003), deeper Clark level invasion (P < .001), and narrower excision margins (P < .001). There were 8 local recurrences, including 6 (6%) in the surgery only group and 2 (7%) in the adjuvant RT group. A positive margin (P < .001) and head and neck location (P = .03) were significant predictors of local recurrence.


CONCLUSIONS
The local recurrence rate in this series was lower than the rates reported in historic control groups and in the authors' previous temporal cohort. The results indicated that clear surgical margins are of paramount importance in minimizing local recurrence; when margins are compromised, the addition of RT may reduce local recurrence rates compared with historic controls. A prospective randomized trial is needed to quantify the risk reduction with adjuvant RT.
Chen
James Y
JY
Department of Radiation Oncology, Sydney Cancer Centre, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia. james.chen@email.cs.nsw.gov.au
Hruby
George
G
Scolyer
Richard A
RA
Murali
Rajmohan
R
Hong
Angela
A
Fitzgerald
Patrick
P
Pham
Trang T
TT
Quinn
Michael J
MJ
Thompson
John F
JF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D010525:Peripheral Nerves / Q000473:pathology; D018714:Radiotherapy, Adjuvant; D012878:Skin Neoplasms / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery*