Primary melanoma thickness correlated with regional lymph node metastases
D. F. Roses, M. N. Harris, D. Hidalgo, Q. J. Valensi and N. Dubin
We studied 119 patients with stage I primary cutaneous malignant melanoma,
who were undergoing regional lymph node dissection, to determine the
relationship of lymph node metastases to thickness of the primary lesion.
The lymph nodes in the dissection specimen were each evaluated by serial
sections. None of the patients with lesions less than 1.0 mm thick had
nodal micrometastases. When lesions exceeded 1.0 mm in thickness, there was
no appreciable increase in the incidence of nodal metastases until a
thickness greater than 4.0 mm was reached, in which cases the incidence of
metastases was 50%. Predictive variables were determined by multiple
logistic regression analysis. Only lesions that were at least 4.0 mm thick
and were not located on the upper extremities were significant predictors
of lymph node metastases; within this category there was a 64% incidence of
lymph node metastases.
