Tumor metrics and morphology predict poor prognosis in prenatally diagnosed sacrococcygeal teratoma: a 25-year experience at a single institution.

PURPOSE: Some fetuses with sacrococcygeal teratoma (SCT) develop hydrops, but there is no consensus on an appropriate prognostic marker for poor prognosis. The purpose of this study is to establish predictors of poor prognosis in fetuses with SCT.

METHODS: A retrospective review of patients with prenatally diagnosed SCT from 1986 to 2011 was performed. Patients with outcome data and ultrasound exams before 32 weeks gestational age (GA) were included (n=37). Tumor volume-to-fetal weight ratio (TFR) and tumor morphology were assessed as sonographic predictors of poor prognosis.

RESULTS: Twelve patients (32%) had good prognosis, and twenty-five patients (68%) had poor prognosis. All patients with poor prognosis had a morphology score ≥ 3, which is a significant predictor of poor prognosis (p <0.0001). TFR was assessed, and a receiver operating characteristic (ROC) analysis identified a cutoff value of 0.12 before 24 weeks GA and 0.11 before 32 weeks GA as predictors for poor prognosis. TFR is a significant predictor of poor prognosis (p<0.0001).

CONCLUSIONS: Patients with cystic SCT all had good prognosis. TFR >0.12 was validated as a sonographic predictor of poor prognosis. TFR and tumor morphology can be used to counsel expectant families with prenatally diagnosed SCT regarding prognosis.