Epithelioid Trophoblastic Tumor Metastatic to the Vagina: An Immunohistochemical and Ultrastructural Study

Abstract

We describe an epithelioid trophoblastic tumor (ETT) metastatic to the vagina in a 30-year-old Japanese woman. A polypoid tumor in the vaginal orifice was composed of nests of intermediate trophoblastic cells that showed a striking epithelioid appearance. In the hysterectomy specimen, a tumor infiltrated through the myometrium and showed histologic findings similar to those of the vaginal tumor. The tumor cells were positive for cytokeratin, inhibin-alpha, and melanoma cell adhesion molecule (Mel-CAM, CD146) but were only focally positive for human placental lactogen. Electron microscopic examination revealed bundles of well-developed, intermediate-type filaments surrounding the nuclei.

Epithelioid trophoblastic tumor: a clinicopathological and immunohistochemical study of seven cases

“…In ETT, immunohistochemical stains for b-hCG, hPL exhibit focal reactivity. This is in distinct contrast to the staining patterns seen in choriocarcinoma and PSTT [7]. In choriocarcinoma, b-hCG is diffusely positive [14], whereas hPL positive cells are less conspicuous.…”

“…All previously reported extrauterine ETT included lung, vagina, broad ligament, fallopian tube, gallbladder, paracervix and parametrium, probably originating from uterine trophoblastic disease [6][7][8][9][10][11][12]. Pancreas metastasis in our study, to our knowledge, was the first case reported.…”

“…Inhibinalpha is a highly sensitive and relatively specific marker for gestational trophoblastic lesions [3]. Furthermore, immunostains for cytokeratin 18 are strongly and diffusely positive in ETT, but are negative or only focally and weakly positive in squamous cell carcinoma [7]. The stain of p16 has recently been demonstrated as a useful aid for differentiating between GTN and cervical squamous cell carcinoma [17].…”

Epithelioid Trophoblastic Tumor: Report of Two Cases in Postmenopausal Women with Literature Review and Emphasis on Cytological Findings

“…Positivity for hCG is usually focal and primarily seen in syncytiotrophoblasts [4,22,24]. Focal positivity can also be seen for human placental lactogen [26]. …”

“…However, the Ki-67 labeling index can range from 2 to 86% with an average of 30% [2,24]. ETT is negative for CK5/6, CD68, S100, desmin, vimentin, TTF1, cytokeratin 20, estrogen receptor, progesterone receptor and p53 [12,22,26]. The hyaline material has been shown to be positive for type IV collagen and fibronectin of oncofetal and adult types [4].…”