Sir,

Malignant melanoma had always an unpredictable course. Even in the same entities clinical outcome varies largely as seen between Lentigo maligna melanoma and acral-lentiginous melanoma in cutaneous melanoma and between choroidal melanoma and ciliary body melanoma in uveal melanoma.

Despite the fact that largest tumour diameter is one prognostic indicator for choroidal melanoma, several authors have tried tumour volume calculation models, as the direct measurement of volume has not found the way into daily routine because of the necessity of special ultrasonic equipment.

The formula used in our calculation model was the half volume of a rotation ellipsoid, rotated around the y-axis, with πa2b, limited to patients with choroidal melanoma, excluding ciliary body melanoma.

In our study, the thus calculated volume turned out to be superior as prognostic indicator than tumour diameter and tumour height.

As mentioned in the discussion, calculated volumes are only theoretical volumes and might be of value to document the tumour regression after globe-preserving treatment and to consider the individual prognosis of the patient with regard to further adjuvant treatment models.

In multivariate analysis, however, it is not unlikely that different patient populations will yield different parameters as most significant predictors. This is particularly true in the case of highly correlated parameters such as tumour diameter and calculated tumour volume. Therefore, only the examination of larger patient cohorts will finally yield a general prognostic model.