Endodermal sinus tumor other diagnostic studies


 * Somal Khan, M.D.

Microscopic Pathology
The histology of EST is variable, but usually includes malignant endodermal cells. These cells express alpha-fetoprotein (AFP), which can be detected in tumor tissue or serum. When there is incongruence between biopsy and AFP test results for EST, the result indicating presence of EST should guide treatment. This is because EST often occurs as small "malignant foci" within a larger tumor, usually teratoma; biopsy of the tumor may reveal only teratoma, whereas elevated AFP in serum or cerebrospinal fluid reveals that EST is also present. GATA-4, a transcription factor, also may be useful in the diagnosis of EST.