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Updated: Jul 11, 2026
Implantation and Evaluation of Melanoma in the Murine Choroid via Optical Coherence Tomography
Published on: December 2, 2022
Expression of vascular endothelial growth factor-A, matrix metalloproteinase-9, and extravascular matrix patterns and
Afsun Sahin1, Hayyam Kiratli2, Figen Soylemezoglu3
1Ocular Oncology Service, Department of Ophthalmology, Hacettepe University School of Medicine, Ankara, Turkey.
Purpose:
To assess extravascular matrix patterns (EMP) and expression of vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-9 (MMP-9) in posterior uveal melanomas and their correlations with histopathologic parameters and metastasis.
Methods:
This study was conducted on 100 consecutive eyes enucleated for posterior uveal melanomas. All tumors were examined by immunohistochemical techniques for VEGF-A and MMP-9 expression, and the presence of EMPs was assessed on routine paraffin sections stained with reticulin. Cell type, tumor localization, degree of pigmentation, necrosis, mitotic index, lymphocytic infiltration, and scleral and optic nerve invasion were analyzed by using light microscopy. No eyes had received prior treatment such as radiotherapy or transpupillary thermotherapy.
Results:
Identified histopathologically, cell types were spindle cells in 60% of the cases, mixed cells in 14%, and epithelioid cells in 26% of tumors. Positive reaction for VEGF-A and MMP-9 was present in 84% and 72% of the tumors, respectively. Microvascular loops and/or networks were seen in 34% of the tumors, with the remaining 16% of the tumors displaying an arc pattern, 21% displaying a parallel pattern, and 29% displaying the normal pattern. The relationships between VEGF-A and MMP-9 expression and necrosis, the degree of lymphocyte infiltration, mitotic rate, and the formation of loop and network patterns were found to be statistically significant (P < 0.05). Metastatic disease developed in 14 patients during follow up.
Conclusions:
The incidence of metastatic melanoma increased with the increasing expression of VEGF-A and MMP-9. Our data suggest that increasing VEGF-A and MMP-9 expression and the EMP can be used as independent prognostic factors in the management of posterior uveal melanoma following enucleation.
Insights
Increased expression of vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-9 (MMP-9) in posterior uveal melanomas correlates with higher metastasis risk. These factors, along with extravascular matrix patterns (EMP), can aid in prognosis after enucleation.
Area of Science:
- Ophthalmology
- Oncology
- Pathology
Background:
- Posterior uveal melanoma is a rare intraocular malignancy.
- Prognostic factors are crucial for patient management and treatment strategies.
Purpose of the Study:
- To evaluate extravascular matrix patterns (EMP) and the expression of vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-9 (MMP-9) in posterior uveal melanomas.
- To correlate these findings with histopathologic features and metastatic potential.
Main Methods:
- Analysis of 100 enucleated posterior uveal melanomas.
- Immunohistochemical assessment of VEGF-A and MMP-9 expression.
- Evaluation of EMP using reticulin-stained sections and light microscopy for histopathologic parameters.
Main Results:
- VEGF-A and MMP-9 expression was detected in 84% and 72% of tumors, respectively.
- Specific extravascular matrix patterns (loop, arc, parallel) were identified.
- Significant correlations were found between VEGF-A/MMP-9 expression, tumor characteristics, and metastatic disease development in 14% of patients.
Conclusions:
- Elevated VEGF-A and MMP-9 expression are associated with an increased incidence of melanoma metastasis.
- VEGF-A, MMP-9, and EMP serve as independent prognostic indicators for posterior uveal melanoma management post-enucleation.
