Submit a formalin-fixed, paraffin embedded tissue block
Formalin-fixed, paraffin embedded (FFPE) tissue block
FFPE tissue section mounted on a charged, unstained slide
Immunohistochemical staining and microscopic examination
If requested, an interpretive report will be provided
If complete hydatidiform mole is present:
Microscopic sections show variably sized villi, virtually all of which are swollen and enlarged with cerebriform contours and cleft-like cisternae, associated with prominent intervillous trophoblastic proliferation. The morphology is quite suggestive of a molar pregnancy. Immunohistochemistry stains for P57 antigen are performed and are negative in the villous mesenchyme and cytotrophoblast, with appropriate positive staining in the intervillous trophoblastic islands, confirming the diagnosis of complete hydatidiform mole. Thus, careful follow up with serial serum HCG levels is recommended to ensure that the levels return to normal.
These results are discussed with Dr. ____ and the report is faxed on _____/
If the differential is between spontaneous abortion and partial hydatidiform mole:
Microscopic sections show swollen villi with a mild degree of trophoblastic proliferation. A P57 immunohistochemical stain is performed, to exclude the possibility of a complete hydatidiform mole. This stain shows positive staining within cytotrophoblast, villous mesenchyme, and intervillous trophoblastic islands, excluding the possibility of a complete hydatidiform mole. Thus, the differential diagnosis of this case includes a spontaneous abortion with hydropic changes vs. a partial hydatidiform mole. Therefore, a paraffin block will be submitted for flow cytometry studies to determine whether or not this tissue is diploid (hydropic POC) or triploid (partial hydatidiform mole). The final diagnosis will be deferred pending the flow cytometry studies. An addendum report will follow.