Placental site trophoblastic tumor presenting with a pneumothorax during pregnancy

Placental site trophoblastic tumor: a case report and review of the literature

Placental site trophoblastic tumor is rare. They represent a rare form of gestational trophoblastic disease. They occur mainly in women who have a history of miscarriage, termination of pregnancy, or even a normal or pathological ongoing pregnancy. The clinical course is unpredictable. This malignancy has different characteristics from other gestational trophoblastic tumors. Following a clinical case that we encountered and treated, we conducted a literary research and review, focusing primarily on prognostic factors and treatment.

[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.

Placental site trophoblastic tumor: A study of 55 cases and review of the literature emphasizing factors of prognostic significance

OBJECTIVE

The placental site trophoblastic tumor is a rare form of gestational trophoblastic disease. Fifteen percent of reported cases have been fatal, but predicting behavior in individual patients has been challenging.

METHODS

The clinical, gross and histopathological features of 55 cases and 180 cases in the literature were analyzed for their effect on survival and in relation to tumor stage.

RESULTS

The 55 patients in our series were 20 to 62 (average 32) years of age. The tumors occurred on an average of 34 months after the last known gestation. 84% were stage I, 2% stage II, 5% stage III, and 9% stage IV. Serum levels of human chorionic gonadotropin (hCG) were elevated (average 691 mIU/ml) in 77% of the cases. The tumors were on average 5 cm in greatest dimension and were composed microscopically of infiltrative sheets of intermediate (extravillous) trophoblastic cells. The mitotic rate ranged from 0 to 20 (average 5.0) per 10 high power fields. The follow-up interval averaged 4.6 years. Eight patients (15%) died from metastatic tumor, and nine additional patients had metastases or a recurrence but were alive at last contact. The most common metastatic sites were the lungs, liver, and vagina.

CONCLUSIONS

Significant factors associated with adverse survival in the present series were age over 35 years (P = 0.025), interval since the last pregnancy of over 2 years (P = 0.014), deep myometrial invasion (P = 0.006), stage III or IV (P < 0.0005), maximum hCG level > 1000 mIU/ml (P = 0.034), extensive coagulative necrosis (P = 0.024), high mitotic rate (P = 0.005), and the presence of cells with clear cytoplasm (P < 0.0005). Only stage and clear cytoplasm were independent predictors of overall survival, while stage and age were the only independent predictors of time to recurrence or disease-free survival. In the literature, factors associated with survival were stage (P < 0.005), interval from preceding pregnancy of over 2 years (P = 0.029), previous term pregnancy (P = 0.046), high mitotic rate (P < 0.0005), and high hCG level (P = 0.037).

Placental site trophoblastic tumor arising from antecedent molar pregnancy

OBJECTIVE

Placental site trophoblastic tumor (PSTT) is a rare form of gestational trophoblastic disease. Little is known about its pathogenesis and natural history.

METHODS

This report describes two cases that arose in patients with documented complete hydatidiform moles and summarizes the antecedent prenatal histories of PSTTs based on a detailed Medline literature analysis.

CASES

A 28-year-old, G(2)P(2) female had a live, 12-week gestation fetus and a coexisting molar pregnancy. Her hCG levels dropped promptly from 1.5 million to 23,273 IU/ml after termination, but rose shortly thereafter together with the onset of recurrent vaginal bleeding. Curettage revealed persistent mole. Persistently elevated hCG led to hysterectomy disclosing a fundal PSTT. The second case was that of a 48-year-old, G(2) woman who presented with symptoms of preeclampsia, hyperthyroidism, and elevated hCG. Curettage yielded a complete hydatidiform mole. Although the hCG level decreased for a short period, it soon increased despite treatment with methotrexate. A second curettage revealed a PSTT.

DISCUSSION

A Medline literature analysis of PSTT, which consists almost entirely of individual cases and several small series, disclosed that PSTT is preceded in 61% of cases by normal term pregnancy, 12% molar pregnancy, 9% spontaneous abortion, 8% therapeutic abortion, and 3% with ectopic pregnancy, stillbirths or preterm delivery. No information is known in 7%. This report describes two additional cases of PSTT preceded by complete molar pregnancy.

CONCLUSIONS

PSTT is a well recognized, but uncommon form of gestational trophoblastic disease. Although little is known about its pathogenesis, it is preceded not uncommonly by an abnormal pregnancy, including a molar pregnancy.