PHYTOESTROGENS AS A CAUSE OF CHILDHOOD GYNECOMASTIA

Abstract

A 5 and 2/12 y.o. male presented with bilateral breast tissue (4.5cm), areolar pigmentation, slight non-velous pubic hair, prepubertal (2cc) testes, and growth acceleration. Height was 120cm (HT-SDS for CA = +1.9), bone age was 10 yrs (HT-SDS for BA = −2.8), predicted final HT 160.6cm (mid-parental HT 172cm). Laboratory studies revealed sex-chromatin negative buccal smear, non-detectable serum and urine estrone, 24-hour urine estrogens 19 ug/gmCr, LH 0.1 mIU/L, FSH 0.7 mIU/L, prolactin 5.9ng/ml, beta-HCG <5mIU/ml. A testicular ultrasound and adrenal steroidogenic profile were normal. On-site environmental evaluation revealed that this child habitually fed calves fresh wet alfalfa mixed with Rumensin, a monocarboxylic, highly lipophilic cation chelating agent. The skin of both arms and hands were exposed repeatedly to the mixture over a 12 month period. Repeated analysis of the alfalfa revealed significant quantities (50 and 35 ppm) of the phytoestrogen coumesterol. Cessation of this activity resulted in gradual reduction in breast size and slowing of skeletal maturation. However, growth velocity of 7.7cm/year, plasma T of 0.36ng/ml, and peak LHRH-stimulated gonadotropins (LH 5.5mIU/L, FSH 3.8mIU/L) suggest probable impending precocious puberty. We propose that gynecomastia and accelerated growth and maturation in this child resulted from topical absorption of the phytoestrogen coumesterol, enhanced by hand-mixing of the wet coumesterol-containing alfalfa with a lipophilic, monocarboxylic ionophore.