Recurrent immature teratoma: Lack of correlation between serum level and immunohistochemical detection of serum alpha-fetoprotein

We present the clinicopathologic and immunohistochemical features of a pure immature ovarian teratoma that had arisen in a 15-year-old girl. At original diagnosis immature extra ovarian implants were noted (grade 3) accompanied by moderately elevated serum alpha-fetoprotein (AFP) levels, AFP was immunohistochemically demonstrable in immature endodermal elements. The immature neural tissue present was negative for AFP, and no other tumor elements were recognisable. Serum AFP fell post-operatively to within normal limits. Despite five courses of chemotherapy and asymptomatic status, the patient re-presented 15 months after original diagnosis with a massive abdominal and pelvic tumor recurrence with predominantly mature glial tissue, but some persistent immature foci, There was no associated increase in serum AFP at this time. AFP was, however, persistently detectable immunohistochemically in immature endodermal components only. Immature neural elements were no longer identified. Disappearance of immature neural tissue in the tumor recurrence may have been related to chemotherapy. This case demonstrates the lack of correlative ability of serum AFP levels with both clinical behaviour and immunohistochemical demonstration of AFP expression in the tumor recurrence.