Neuroendocrine Transformation of a Presacral Teratoma in Two Patients with Currarino Syndrome (#360)
Introduction
Currarino syndrome (CS) is a rare, autosomal dominant disorder associated with germline mutations in the homeobox gene, HLXB9. It is typically characterised by anorectal malformations, partial sacral agenesis and presacral mass (anterior meningocoele or teratoma). However, the phenotype is variable often with only occult sacral abnormalities or presacral mass on imaging. Malignant degeneration of the teratoma is estimated at 1% but evidence is sparse. The histological appearances are varied but there are at least four cases of neuroendocrine transformation reported in the literature.
Aim
To report two cases of metastatic neuroendocrine tumour (NET) associated with CS.
Methods
A 43 yo Egyptian man presented with an enlargening presacral mass and sacral dural ectasia on MRI. There was no family history of anorectal malformations however his sister had a history of midline teratoma and anterior sacral meningocoele. Surgical resection demonstrated a NET (Ki67 5-10%) arising from a presacral teratoma. Ten months later, 68Ga-DOTATATE PET detected pelvic and para-aortic nodal recurrence. 177Lu-DOTATATE (LuTate) therapy was pursued with complete response.
A 69 yo Caucasian woman presented with gross hepatomegaly and weight loss. Imaging showed widespread metastatic disease and sacral malformation. Her son had died from a malignant presacral teratoma at age 13. A diagnostic liver biopsy demonstrated NET (Ki67 6%). 68Ga-DOTATATE PET demonstrated intense dotatate avidity in a presacral mass and perirectal nodes as well as extensive liver and bone metastases. There was no FDG avidity. LuTate therapy was completed however sadly she died from hepatic failure.
Results
A germline mutation in HLXB9 associated with CS was identified in both cases. Subsequently, 7 mutation carriers and 8 non-mutation carriers were identified.
Conclusion
Although rare, clinicians and surgeons should be aware of CS and its clinical variability, as well as the possibility of neuroendocrine transformation of a presacral teratoma. The diagnosis clearly has important implications for screening and surveillance of at-risk relatives.