Clinical Features Differentiating Benign From Malignant Conjunctival Tumors in Children.

Importance: Conjunctival tumors in children are usually benign and rarely malignant.

Objective: To evaluate clinical features of conjunctival tumors in children by comparing benign tumors with their malignant counterparts.

Design, Setting, and Participants: This retrospective case series reviewed 806 cases of conjunctival tumor in children (aged <21 years) who were evaluated at a tertiary referral center between November 1, 1975, and July 1, 2015. This study included 262 children who were part of a published review.

Main Outcomes and Measures: Features of benign and malignant tumors were compared. Data were collected on patient demographics, tumor features, and specific diagnoses to determine findings related to each tumor.

Results: Among the 806 patients with conjunctival tumor, the top 5 diagnoses included nevus (492 [61%]), benign reactive lymphoid hyperplasia (BRLH) (38 [5%]), nodular conjunctivitis (31 [4%]), dermoid (30 [4%]), and primary acquired melanosis (27 [3%]). Overall, conjunctival tumors were benign (779 [97%]) or malignant (27 [3%]), including melanoma (18 [2.2%]) and lymphoma (9 [1.1%]). The mean age at detection was 11 years for benign tumors and 14 years for malignant tumors (P = .005), with mean difference of 3 years (95% CI, 1.2-4.6). The relative frequency of any malignancy (per all conjunctival tumors) by age bracket (0-5 years, >5-10 years, >10-15 years, and >15-<21 years) was 1%, 2%, 3%, and 7%, respectively. A comparison between nevus and melanoma found differences with melanoma in the 10 to 15 years age bracket (29% vs 61%; difference of 32% [95% CI, 10%-55%]; P = .006), mean tumor thickness (1.1 mm vs 1.5 mm; difference of 0.4 mm [95% CI, -0.29 mm to 1.12 mm]; P = .04), tumor base of 10 mm or greater (relative risk [RR] = 4.92; 95% CI, 1.73-13.97; P = .003), tumor hemorrhage (RR = 25.30; 95% CI, 11.91-53.78; P < .001), and lack of intrinsic cysts (RR = 5.06; 95% CI, 1.84-13.98; P = .002). A comparison between BRLH and lymphoma revealed lymphoma with a larger base (RR = 5.16; 95% CI, 1.19- 22.19; P = .002) and diffuse location (RR = 16.50; 95% CI, 4.31-63.22; P < .001) and inferior (RR = 12.38; 95% CI, 2.88-53.16; P < .001) or superior vs nasal (RR = 8.25; 95% CI, 1.56-43.51; P = .01). The small cohort of malignant lesions precluded determining if these features were independent of one another.

Conclusions and Relevance: These data, from an ocular tertiary referral center, suggest that conjunctival tumors in children are nearly always benign. The few malignant tumors included melanoma and lymphoma. Melanoma, compared with nevus, was associated with older children (aged >10-15 years) with larger tumor, hemorrhage, and lack of cyst. Lymphoma, compared with BRLH, was associated with larger size and diffuse involvement.