Ocular Oncology and Pathology
This domain tests intraocular tumors, eyelid and conjunctival malignancy, masquerade syndromes, and basic pathology. The exam stresses safe diagnosis and metastasis surveillance.
Core ocular oncology
- Uveal melanoma: choroidal tumor with BAP1 mutation; metastasizes to the liver. Treat with plaque brachytherapy or enucleation; screen the liver with ultrasound or MRI.
- Retinoblastoma: RB1 mutation, leukocoria, and calcification on CT. Genetic testing is essential; treatment includes chemotherapy and enucleation. Avoid biopsy because of seeding risk.
- Vitreoretinal lymphoma: masquerade with vitreous cells; CNS involvement is common; diagnosis requires cytology or biopsy.
- Conjunctival melanoma and OSSN: UV exposure; topical therapy or excision.
- Pathology: specimen orientation and immunohistochemistry; melanoma markers include HMB-45 and Melan-A; lymphoma markers include CD20.
Worked example
A 3-year-old has leukocoria and calcification on CT. Reasoning: retinoblastoma. Do not biopsy; refer for genetic testing and oncology.
Traps
Never biopsy a suspected retinoblastoma. Uveal melanoma metastasizes to the liver first, not the lungs.