Regression in thin malignant melanoma. Microscopic diagnosis and prognostic importance.


Forty-eight malignant melanomas of the extremities, 1 mm or less in maximal thickness, were studied to better define microscopic criteria of regression in thin melanomas. Eleven tumors (23%) exhibited definite regression in the form of one or more segmental areas (defects) where the invasive component was replaced by mononuclear cell infiltrate and fibrosis… (More)