Background Flashcards
What is the incidence of intraocular melanoma in the United States, and how does it rank in terms of incidence among the various eye malignancies? Is there a race of gender predilection?
Appx 5 in 1 million (∼2,500 cases/yr of ocular melanoma). Intraocular melanoma is the #1 primary adult intraocular malignancy (#1 overall is ocular mets). 98% of pts are Caucasian, and the incidence is slightly higher in males than females.
What are some of the risk factors for developing ocular melanoma?
Occupational UV exposure, fair skin, light eye color, family Hx of ocular melanoma, and personal Hx of cutaneous melanoma or cutaneous nevi.
What is the most common site in the eye where ocular melanomas arise?
Uvea, mostly choroidal (85%) > adnexa (10%) > conjunctiva (5%)
What is the cell of origin for ocular melanoma?
Ocular melanoma arises from melanocytes of the uveal stroma (neural crest origin).
What are the components of the uveal tract?
The choroid, ciliary body, and iris comprise the uveal tract.
What is the association b/t uveal melanoma location and metastatic risk?
Ciliary body involvement carries the highest risk of death from mets, f/b choroidal tumors. Iris tumors carry the most favorable prognosis.
Name the layers of the choroid from outer to inner.
Layers of the choroid (outer to inner):
Haller layer
Sattler layer
Choriocapillaris
Bruch membrane
What are the basic layers of the globe?
Outer fibrous layer (sclera), middle vascular layer (choroid), and inner nerve layer (retina)
What region in the retina is particularly important for color vision?
The macula is important for color vision.
Where is the optic disc relative to the macula?
The optic disc is 2 mm medial to the macula (∼1.5 mm in diameter).
What are the histologic subtypes of ocular melanoma, and which carry the best and worst prognosis?
Spindle cell (best), epithelioid (worst), and mixed (if <50% epithelioid histology)
What % of pts with ocular melanoma present with DM at Dx? What is the most common location?
1%–2% present with DM. The liver is the most common site (89% in COMS).
What are the different ways melanoma can spread within the globe?
Melanoma can spread intraocularly (through the vitreous, aqueous, or along ciliary vessels/nerves); extraocularly (through the optic nerve, transsclerally, vascular tracking), and through extrascleral extension (10%–15%).
What tumor characteristics predict for DM in ocular melanoma? What is the 5-yr mortality rate in these pts?
Epithelioid histology, large tumors, ant location (ciliary body invasion), monosomy 3 often combined with gain in chromosome 8q, scleral penetration, ↑ mitotic rate, ↑ Ki-67, pleomorphic nucleoli, optic nerve invasion, ↑ MIB-1 index, vascular networks of closed vascular loops, extraocular extension. The 5-yr mortality rate is 55%.
How has Gene Expression Profiling (GEP) been used to predict DM? What genetic mutation has also been discovered to be associated with DM?
GEP has been used to differentiate tumors with high-risk class 2 associated with ↑ DM. Mutations in the BAP1 gene on chromosome 3 have been associated with ↑ DM. PRAME expression has also been associated with DM risk as well.
