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Presentation type	E-poster
Title	Next-Generation Sequencing for Excised Conjunctival Naevi: Does More Data Equal Better Care?

Purpose	To evaluate the benefits and risks of next-generation sequencing (NGS) in excised conjunctival naevi in children.
Methods	Two pediatric cases of excised conjunctival naevi were reviewed.
Results	In the first case (boy - 10y), NGS identified a BRAF V600E pathogenic variant in a histologically benign conjunctival naevus. Although BRAF V600E is also found in benign conjunctival naevi, the presence of an involved surgical margin caused uncertainty and concern for the patient’s parents. Following a multidisciplinary consultation with the department of Pathology and Medical Genetics, it was unanimously decided to classify this lesion as benign. Consequently, no wider resection or adjuvant therapy was performed. In the second case (girl – 13y), a MAP2K1 mutation and a pathogenic BRCA1 variant were detected in a melanocytic nevus. MAP2K1 alterations may occur in both benign and malignant melanocytic lesions. Further analysis showed a low BRAC1 variant allele frequency, which classified the mutation as somatic and not part of a germline mutation.
Conclusion	NGS can provide valuable information about conjunctival melanocytic lesions. However, more molecular data does not automatically result in better clinical care. In histologically confirmed benign conjunctival naevi, the presence of BRAF V600E or MAP2K1 mutations does not always allow one to distinguish between benign and malignant disease. Therefore, NGS may increase uncertainty for both patients and surgeons. A multidisciplinary approach is essential for proper patient counseling.
Conflict of interest	No

Authors 1

Last name	VANDERMEULEN
Initials	M
Department	Department of Ophthalmology, Ghent University Hospital
City	Ghent

Authors 2

Last name	DIMITRI
Initials	R
Department	Department of Ophthalmology, Ghent University Hospital
City	Ghent