Work-up & Staging Flashcards
What is the DDx for a pediatric brain tumor in the pineal region?
Pineoblastoma, pineocytoma, PPT of intermediate differentiation, germinoma, NGGCT, glioma, meningioma, lymphoma, benign cyst, Langerhans cell histiocytosis, hamartoma; most are germ cell tumors.
What is the DDx for a pediatric brain tumor in the suprasellar region?
Germinoma, NGGCT, craniopharyngioma, pituitary adenoma, meningioma, glioma, aneurysm, infection, mets
What is the workup for a suspected germ cell tumor?
Suspected germ cell tumor workup: H&P (esp CNs, funduscopic exam), MRI brain/spine, basic labs, serum AFP/β-HCG, CSF AFP/β-HCG (more sensitive than serum), and CSF cytology
What AFP levels exclude the Dx of a germinoma?
An AFP >10 ng/mL excludes the Dx of pure germinoma.
What a-HCG levels exclude the Dx of germinoma?
None are truly exclusive, but if the β-HCG is >50 ng/mL, then it probably is not a germinoma. Very high levels are consistent with choriocarcinoma.
What stain definitively confirms the Dx of a germinoma?
PLAP staining confirms the Dx of germinoma.
What is the role of Sg in Dx of GCT?
If AFP and β-HCG are normal, Sg can distinguish pure germinoma or mature teratoma from other benign or malignant lesions. If β-HCG is elevated but normal AFP, Sg can distinguish β-HCG secreting germinoma from immature teratoma or choriocarcinoma (i.e., NGGCT).
What are the typical MRI findings of pure germinoma? Are there any distinctions on imaging from NGGCTs?
Homogeneous or heterogeneous pattern, hypointense T1, hyperintense T2, +Ca, cysts. These are indistinguishable from NGGCTs on imaging.
Historically, how was RT used in the Dx of intracranial germinomas?
Tumors were irradiated with a diagnostic dose of 10–20 Gy. If there was a response, then the Dx was germinoma and RT was continued to a definitive dose of 40–56 Gy. This is no longer done.
What staging system is used for intracranial GCTs M staging?
The medulloblastoma staging (modified Chang) system is used for staging of intracranial GCTs M staging, but usually M0 or M+ (disseminated) is adequate.
