Uveal melanoma (UM) is the most common primary intraocular malignancy in adults
with an incidence of 7-10/ million and has a predilection for hematogenous dissemination
to the liver. Despite improvements in diagnosis and treatment of this intraocular
tumor, there has not been a change in survival in the past decades. There is no effective
treatment for liver metastases resulting in tumor-related death in about 45% of UM
patients within 15 years after the initial diagnosis.
Uveal melanoma usually arises ‘de novo’ from melanocytes derived from neural crest
cells that have migrated to the epidermis and uveal tract during embryogenesis. Intraocular
melanoma may arise in the choroid (70-80%), ciliary body (10-20%) and iris
(5-10%). Iris melanomas are the least common and tend to present at a smaller size,
probably because pigmented lesions of the iris are usually visible to the patient. Iris melanomas
can cause drainage angle blockage and secondary elevation of the intraocular
pressure.4 Melanomas located in the ciliary body are associated with a high metastatic
potential. Choroidal melanomas compromise the majority and grow subretinal in a
discoid, dome-shaped or mushroom-shaped pattern.
The diagnosis is based on the clinical appearance of the tumor on ophthalmic examination.
Ancillary tests include (Doppler-) ultrasonography, transillumination, fluorescein
angiography and optical coherence tomography. For the diagnosis of melanoma, biopsy
is reserved for tumors of uncertain origin. Conversely, tumor biopsy gains territory in
vision-sparing therapies for cytogenetic analysis providing risk assessment of metastatic
disease.
Upon diagnosis of the primary tumor, patients are screened for metastases by liver
enzyme tests and liver ultrasound. At time of diagnosis less than 2% of the patients have
detectable metastases.http://repub.eur.nl/res/pub/19569/100526_Mensink%2C%20Hanneke%20Willemijn.pdf
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