A retrospective analysis of 41 patients treated for metastatic inguina
l lymph node malignant melanoma is presented: 16 underwent inguinal no
de excision and 25 ilioinguinal node excision. The two groups were wel
l matched for age, sex and other characteristics. The mean time in hos
pital (inguinal 20 days, ilioinguinal 18 days) and the complication ra
tes (inguinal, ten of 16 patients, ilioinguinal, 13 of 25) were simila
r in each group. The incidence of groin relapse, defined as the develo
pment of symptomatic melanoma in the region of the inguinal or iliac n
ode basins following block dissection, was lower after ilioinguinal bl
ock dissection (inguinal, three patients; ilioinguinal, none). Histolo
gical examination demonstrated a high proportion of iliac node involve
ment (13 of 25 patients), even in those with a single mobile inguinal
lymph node clinically and no clinical or computed tomographic evidence
of iliac node involvement. This supports the value of ilioinguinal bl
ock dissection and suggests that the associated morbidity need not be
greater than that associated with inguinal clearance alone.