A prognostic index for patients with malignant melanoma of the conjunctiva.

From 1968 to 1984, 31 patients with histologically proven malignant melanoma of the conjunctiva were treated and followed in the Eye Hospital of the University of München. Histological demonstration of tumor thickness and the mitotic index (number of mitoses per square millimeter) gave a the prognostic index, in which tumor thickness was multiplied by the mitotic index. This index then allowed evaluation of the risk for tumor metastasis. Most tumors measured less than 1.5 mm in thickness, and the metastatic risk was low or medium in these cases. All tumors of the low metastatic risk group had a prognostic index of 1 or less, while all recurrences were associated with a prognostic index that exceeded 1.