Placental site trophoblastic tumour (trophoblastic pseudotumour): a study of four cases requiring hysterectomy including one fatal case.

The clinico-pathological features of four patients with placental-site trophoblastic tumour (trophoblastic pseudotumour) are presented. One patient had the nephrotic syndrome associated with evidence of disseminated intravascular coagulation, with complete resolution after hysterectomy. In two patients the tumour extended beyond the uterus, and one of them died with many metastases in spite of intensive post-operative chemotherapy and 'second look' laparotomy. In three patients the tumour behaved as an actively infiltrative neoplasm resistant to chemotherapeutic regimes usually effective for choriocarcinoma. Serum HCG levels were relatively low compared with those of choriocarcinoma. Histologically the tumours were predominantly composed of mononuclear cells supported by a variable amount of vascular stroma and lacked the bilaminar structure characteristic of choriocarcinoma. Scattered cells stained positively with anti-beta HCG and anti-alpha HCG antisera. Prior curettage was diagnostic in two of three cases. We did not find a clear correlation between mitotic activity and subsequent behaviour. Inflammatory cell infiltration and evidence of organisation around the tumour may be favourable prognostic indicators. We agree with a recent publication stressing the variable behaviour of this tumour, and emphasize the importance of serum HCG monitoring. Total surgical excision is usually feasible and in aggressive cases offers the best chance of eradication. We support the recent suggestion that 'trophoblastic pseudotumour' is an unsuitable name for a potentially lethal disease.