Background: Review of the literature of the peculiar nodule in the perineum
of female infants disclosed that the analysis of incidence by gender, obse
rvation of the course, histopathologic assessment, and the pathogenesis of
the abnormality was suboptimal. Objective: We therefore planned to study a
large number of children to analyze the incidence by gender, the course, an
d the pathogenesis of the peculiar perineal nodules. Methods: Of 500 childr
en (224 boys and 276 girls) who ranged from newborn to 11 years of age, occ
urrence of the perineal nodules was checked. When nodules were found, the s
ite, shape, size, number, and the onset were examined. Histopathologic exam
ination and observation of the course were carried out in some cases. Resul
ts: None of the boys in our population had nodules, but 13% of the girls di
d. These lesions always occurred as a single peanut-, hen's crest-, or tong
ue tip-shaped nodule on the perineal midline, and 93% of the lesions had be
en present since birth. Histologically, the nodule was an outward projectio
n of essentially normal, redundant skin, showing no evidence of lichen scle
rosus et atrophicus. Conclusion: In view of these findings, we conclude tha
t perineal nodules are a kind of developmental anomaly occurring mostly in
girls. Copyright (C) 2000 S. Karger G, Basel.