Metastatic placental site trophoblastic tumor. Diagnosis after pneumothorax

Placental site trophoblastic tumor (PSTT) is a rare, mostly benign tumor, which in 10-15% of cases shows a malignant behavior. The case of a 35 year old woman with pulmonary metastasis of a PSTT is reported. This finding was incidental in an atypical lung-resection due to pneumothorax. The literature on this rare tumor entity is reviewed especially in terms of differential diagnosis, biological behavior and association with a pneumothorax.