ABO Ocular Oncology 1 — Questions and Answers
Question 1: What is the most common primary intraocular malignancy in adults?
- Retinoblastoma
- Uveal melanoma (Correct answer)
- Primary intraocular lymphoma
- Metastatic carcinoma
Correct answer: Uveal melanoma
Uveal melanoma is the most common primary intraocular malignancy in adults, arising from melanocytes in the uveal tract (iris, ciliary body, choroid).
Question 2: Which genetic mutation is most commonly associated with uveal melanoma?
- BRAF V600E
- GNAQ/GNA11 (Correct answer)
- KRAS
- RB1
Correct answer: GNAQ/GNA11
GNAQ and GNA11 mutations are found in approximately 80-90% of uveal melanomas, constitutively activating the MAPK signaling pathway.
Question 3: What is the most common site of distant metastasis from uveal melanoma?
- Lung
- Brain
- Liver (Correct answer)
- Bone
Correct answer: Liver
The liver is the predominant site of metastasis in uveal melanoma, with over 90% of patients with metastatic disease having hepatic involvement due to hematogenous spread.
Question 4: Retinoblastoma results from biallelic inactivation of which tumor suppressor gene?
- TP53
- BRCA1
- RB1 (Correct answer)
- NF1
Correct answer: RB1
Retinoblastoma results from biallelic inactivation of the RB1 tumor suppressor gene, illustrating Knudson's classic 'two-hit' model of carcinogenesis.
Question 5: Which of the following is the most common benign intraocular tumor in adults?
- Choroidal hemangioma
- Choroidal nevus (Correct answer)
- Iris cyst
- Melanocytoma
Correct answer: Choroidal nevus
Choroidal nevi are the most common benign intraocular tumors, found in approximately 6-7% of the adult Caucasian population, analogous to cutaneous nevi.
Question 6: The Collaborative Ocular Melanoma Study (COMS) demonstrated equivalence between enucleation and which treatment for medium-sized choroidal melanoma?
- External beam radiation
- I-125 episcleral plaque brachytherapy (Correct answer)
- Proton beam radiation
- Transpupillary thermotherapy
Correct answer: I-125 episcleral plaque brachytherapy
COMS demonstrated that I-125 episcleral plaque brachytherapy provides equivalent 5-year overall survival to enucleation for medium-sized choroidal melanomas.
Question 7: Which B-scan ultrasonography finding is most characteristic of choroidal melanoma?
- High internal reflectivity
- Low-to-medium internal reflectivity with acoustic hollowing and choroidal excavation (Correct answer)
- Dense calcification
- Cystic spaces with septations
Correct answer: Low-to-medium internal reflectivity with acoustic hollowing and choroidal excavation
Choroidal melanoma characteristically shows low-to-medium internal reflectivity with acoustic hollowing (angle kappa) and choroidal excavation on standardized A/B-scan ultrasonography.
ABO Ocular Oncology 1
What is the most common primary intraocular malignancy in adults?