J Pediatr Urol 2018 Feb 13; [EPub Ahead of Print], B Karmazyn, DL Weatherly, SJ Lehnert, MP Cain, R Fan, SG Jennings, F Ouyang, M Kaefer
Testicular tumors in children have two peaks with different types of tumors; in the first 4 years of life a third to half are benign with increased risk of malignancy during puberty. The pathology of testicular tumors between these peaks, at the age of 5-12 years, is not known. We hypothesized that because of the low level of testosterone at this time, the incidence of malignant tumors is very low.
To compare malignancy risk of primary testicular tumors in children in the prepubertal period (5-12 years) compared with younger (0-4 years) and pubertal (13-18 years) children.
We retrospectively (2002-2016) identified patients <18 years with surgery for primary testicular tumor. Patients with testicular tumor risk were excluded. Ultrasound studies were reviewed for contralateral testis volume, tumor morphology, and tumor maximal diameter, for three age groups: 0-4, 5-12, and 13-18 years. The Freeman-Halton extension of the Fisher exact probability test was adopted for categorical outcomes, and one-way ANOVA for continuous outcomes.
Fifty-two patients (mean age 11.0 years, range 6 days-18 years) were identified. Malignant tumor prevalence significantly differed (p < 0.01) among age groups (Fig).: 0-4 (72.7%, 8/11), 5-12 (0%, 0/16), and 13-18 years (44.0%, 11/25). The most common tumor types in 5-12 years were epidermoid cyst (31.3%, 5/16) and tumor mimics (37.5%, 6/16). Prevalence of cystic tumors in 5-12 year olds was not significantly different compared with other age groups. Contralateral testicular volume >4 mL (pubertal surge) significantly (p < 0.01) differed among groups: 0-4 years (0/11), 5-12 years (3/16), and 13-18 years (19/20). In children aged 13-18 years the mean tumor maximal diameter (29.8 ± 4.4 mm) was significantly larger (p < 0.01) compared with children 5-12 years (9.3 ± 5.5 mm) and all malignant tumors had contralateral testicular volume >4 mL.
We found that preadolescent children between the ages of 5 and 12 years have distinctive characteristics compared with the other age groups. Most importantly, no malignant testicular tumors were found in this age group. About a third of the children presented with an incidental testicular mass. The testicular tumors were significantly smaller (9.3 ± 6.7 mm) compared with those in children aged 13-18 years (29.8 ± 4.4 mm). There were limitations because of the retrospective nature of the study.
We found no malignant testicular tumors in children aged 5-12 years with no risk factors and prior to pubertal surge. Our study suggests use of more conservative treatment in this group of patients.