RESUMEN
Chromosomal abnormalities that involve the MYCN gene are rare; however, it is one of the most commonly mutated genes in retinoblastoma (RB) after the RB1 gene. MYCN is amplified in approximately 1-9 % of all RB tumors. It plays a role in RB oncogenesis via many mechanisms, including synergism with RB1 deletion, positive feedback with MDM2, upregulation of cell cycle regulating genes, upregulation of miRNA, and upregulation of glucose metabolism. MYCN amplifications are not mutually exclusive and can occur even in the presence of RB1 gene mutations. Clinically, RB1+/+MYCNA tumors present as sporadic, unilateral, advanced tumors in very young children and tend to follow an aggressive course. Magnetic resonance imaging features include peripheral tumor location, placoid configuration, retinal folding, tumor-associated hemorrhage, and anterior chamber enhancement. Genetic testing for MYCNA is especially recommended in patients with unilateral RB where genetic blood testing and tumor tissue show a lack of RB1 mutation. MYCN-targeted therapies are evolving and hold promise for the future.
RESUMEN
Introduction: Conjunctival nevi are benign tumors that are commonly located at the nasal or temporal limbus and rarely in the fornix or tarsus. We report a case of a patient presenting with a solitary compound cystic nevus of the conjunctival fornix in the background of bilateral complexion-associated melanosis. Case Presentation: A 71-year-old African-American female was referred for evaluation of an incidentally noted melanocytic lesion of the right conjunctival fornix. The patient underwent an excisional biopsy, revealing histological features consistent with a compound cystic nevus. Conclusion: This finding is noteworthy due to the rarity of conjunctival nevi originating in the fornix. The case underscores the importance of excisional biopsy in evaluating conjunctival forniceal melanocytic lesions to exclude malignant melanoma, a critical consideration for prognosis.
RESUMEN
In the current era of global health awareness for retinoblastoma (RB), the challenge that lies ahead of us is providing optimal care for children affected with RB in underdeveloped nations. The understanding of similarities and disparities between various nations across the world aids in achieving comparable outcomes. With dissolving geographic barriers and evolving collaboration, global collaborative studies on RB are becoming increasingly common. They provide real-world, robust evidence on several aspects of RB. This review discusses insights gained from global RB studies regarding the demographics, certain aspects of etiopathogenesis and epidemiology, international travel burden, disparities in clinical presentations based on national income levels, management protocols, pathology, treatment outcomes, and the effect of COVID-19 on RB care across the world. These insights are likely to impact individual practice as well as inform policy reforms.