Gestational Trophoblastic Disease

Question No. 1. The Answer is: (D) hCG and hPL.

Discussion: This is a placental site nodule (PSN) with the following characteristic features:

• Well-circumscribed lesion with eosinophilic acellular material in the center;
• The lesion border is surrounded by an intense lymphocytic infiltration and occasional decidualized cells.
• hyaline material containing scattered chorionic-type intermediate trophoblast (IT);
• chorionic-type IT with smudged nuclei;
• rare mitotic figures.

The differential diagnosis in this case is an invasive squamous carcinoma from the cervix. PSN is positive for HLA-G but negative for p16. In contrast, invasive cervical squamous carcinoma is negative for HLA-G but is positive for p16. Reactivity for cytokeratin AE1/AE3 and vimentin does not allow differentiation of PSN from invasive carcinoma. The cells in PSN are positive for hCG and hPL. Invasive squamous cell carcinoma are negative for hCG and hPL.

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