Sacrococcygeal Teratoma

sacrococcygeal teratoma

This female neonate presented with an antenatal diagnosis of sacrococcygeal teratoma. CT was performed shortly after birth for surgical planning. The sagittal reformat from multi-detector row helical CT shows a large extrinsic and small presacral component. The lesion is predominantly cystic, with only a small perineal / coccygeal solid portion.

Seventy to eighty percent of all foetal / neonatal teratomas occur in the sacrococcygeal region. They are 4 times more common in females. Sacrococcygeal teratomas are classified into 4 types: type I – external mass only; type II – predominantly external with presacral extension (this case); type III – external and internal with extension to abdominal cavity; type IV – entirely internal. The tumour must be completely resected to avoid malignant transformation, which occurs in 5%–10% of cases diagnosed before 2 months of age and increases to 50%–90% for those diagnosed at 2–4 months of age. The importance of imaging the internal component should be clear.

Associated anomalies include: hydronephrosis; renal dysplasia; urethral atresia; urinary ascites; hydrocolpos; cryptorchidism; rectal atresia or stenosis; dysplastic hips; and clubbed feet.

There are significant in utero complications which may occur including polyhydramnios, oligohydramnios, high output cardiac failure, and hydrops. There are also increased maternal complications, including toxaemia.

Foetal MRI is a useful modality for imaging the tumour, and can give better delineation of the internal component than ultrasound.

Reference: Woodward PJ et al. A Comprehensive Review of Fetal Tumors with Pathologic Correlation. RadioGraphics 2005;25:215-242

Credit: Dr Laughlin Dawes