Which of the following is not of prognostic significance to choroidal melanoma ?
Prognosis of choroidal melanoma depends upon :-

Cell type
Size of tumor
Location of tumor
Evidence of invasion (extrascleral or vortex vein)
Age of the patient
Cytology
Chromosomal abnormalities.
Presence of retinal detachment
Size of the tumour
Cytology of the tumor cells
Presence of extraocular extension