sentinel vessel sign
A dilated episcleral vessel overlying a choroidal tumor, representing increased vascular flow and serving as an external indicator of intraocular pathology.
Full Definition
The sentinel vessel sign refers to the presence of one or more dilated, tortuous episcleral vessels that course over or adjacent to an underlying choroidal tumor. These vessels represent arterialized vortex veins or dilated posterior ciliary arteries that have enlarged in response to increased metabolic demands or altered hemodynamics associated with tumor growth. The sentinel vessel typically appears as a salmon-colored, engorged vessel visible on external examination and may be the only external sign of an intraocular malignancy. This clinical finding is particularly valuable in detecting posterior choroidal tumors that may not be readily visible on routine ophthalmoscopy, and its presence should prompt comprehensive dilated fundus examination and appropriate imaging studies.
Usage
Usage note: Document vessel location and characteristics; indicates need for comprehensive posterior segment examination.
In Context
- "The presence of a sentinel vessel sign prompted fundoscopic examination, which revealed the underlying choroidal melanoma." — Clinical examination findings
- "Photography documented the sentinel vessel sign for comparison during post-treatment follow-up visits." — Clinical documentation