Scalp metastases mimicking alopecia areata. First case report of placental site trophoblastic tumor presenting as cutaneous metastasis.

BACKGROUND

Placental site trophoblastic tumor (PSTT) is a rare neoplasm of intermediate trophoblastic cells of the placenta. There is a wide range of biologic behavior, with metastases occurring in about 15% of cases. Cases with metastases have all presented with abnormal vaginal bleeding or gynecological symptoms.

METHODS

We describe a 31-year-old G3P3003 woman who presented with several alopecic patches resembling alopecia areata, which on biopsy proved to be metastatic, previously unsuspected, PSTT.

CONCLUSIONS

This represents the first case in which PSTT presented initially with metastases, and specifically, with cutaneous metastases. A new primary tumor source of alopecia neoplastica is presented. The role of mitotic counts in predicting prognosis in PSTT is supported. Alopecia areata was mimicked very closely. Dermatologists should be alert to any features atypical of alopecia areata, including erythema, induration, or palpability, and maintain a low threshold for biopsy in atypical cases.