Ovarian cyst in a premature infant treated with spironolactone.

We describe the late occurrence of an ovarian cyst in a premature infant, the second of a set of monochorionic diamnionic twins, during treatment with spironolactone. Spironolactone is commonly used in the management of neonatal chronic lung disease in combination with other diuretics because of its potassium-sparing effect. It has progestational activity and has been reported to cause gynecomastia. It is used widely for its antiandrogenic properties in the treatment of female hirsutism and hyperandrogenism and it has a role in the management of familial male-limited precocious puberty. However, the estrogenic influence induced during therapy may significantly alter the hormonal milieu in newborn females, resulting in the formation of ovarian cysts. Simple ovarian lesions <5 cm merit close ultrasonographic surveillance for resolution while larger complex masses may warrant surgical intervention.