Van Wyk and Grumbach syndrome is a medical condition defined by a combination of hypothyroidism, precocious puberty (with delayed bone age and lack of pubic hair), and ovarian cysts in pre- and post-pubertal girls or macroorchidism (unusually large testes) in boys.
Symptoms are ascites, pleural and pericardial effusions, elevated ovarian tumour markers, enlarged pituitary gland and elevated prolactin and alpha-fetoprotein levels.
The presumed pathogenesis is that primary hypothyroidism causes enlargement and hyperstimulation of the pituitary gland which in turn cause ovarian hyperstimulation, ovarian cysts and precocious puberty.
Diagnosis is made by imaging/sonography and thyroid hormone tests.
The syndrome usually responds well to thyroid hormone replacement with complete resolution of symptoms.
The syndrome was described in 1960 by Van Wyk and Melvin M. Grumbach.