Dysgerminoma in mother and daughter: use of lactate dehydrogenase as a tumor marker in the child.

A 7-year-old girl presented with an extragonadal dysgerminoma arising from the pelvis. Her mother had been treated for a histologically identical pituitary tumor 3 years previously. The child's serum lactate dehydrogenase (LDH) level was markedly elevated at presentation and fell as the tumor responded to treatment. The potential use of LDH as a marker for gonadal dysgerminoma is well documented, but raised LDH in association with primary extragonadal dysgerminoma has not been described previously. In addition, this is the first report of extragonadal dysgerminoma occurring in female relatives.