Histopathology of tubal pregnancy

Significance of trophoblastic infiltration into the tubal wall in ampullary pregnancy

A total of 81 patients with an ampullary ectopic pregnancy undergoing salpingectomy were enrolled in the study. The ampullary pregnancies were classified according to the depth of trophoblastic infiltration into tubal wall as follows: Stage I, limited to mucosa; Stage II, extension to the tubal muscularis; Stage III, complete tubal wall infiltration up to the serosa. An association was observed between serum β-human chorionic gonadotropin (β-hCG) levels and the depth of trophoblastic infiltration. Significantly higher severe ischemic changes and rupture of tubal wall were observed in patients with stage III infiltration compared with the other groups. A significant association was found between the absolute depth of trophoblastic invasion and severe ischemic changes, and also rupture of serosa. In conclusion, serum β-hCG levels are associated with depth of trophoblastic invasion into the tubal wall, severe ischemic changes, and rupture of the tubal wall.

Could serum β-hCG levels and gestational age be the indicative factors for the prediction of the degree of trophoblastic invasion into tubal wall in unruptured ampullary pregnancies?

OBJECTIVE

To evaluate the predictive value of gestational age and maternal serum β-hCG concentration for the determination of the depth of trophoblastic invasion into the tubal wall.

METHODS

This is a retrospective trial conducted on women with a diagnosis of ampullary pregnancy (71) who were submitted to salpingectomy. Serum β-hCG measurements were obtained at the initial admission of hospital. Histological investigation was performed by a single well-experienced pathologist who was blind to the clinical and laboratory characteristics of the patients. Ampullary pregnancy was classified histologically according to the depth of trophoblastic infiltration into tubal wall: trophoblast limited to the tubal mucosa (stage I), extended to muscularis layer (stage II) and complete tubal wall infiltration up to serosal layer (stage III).

RESULTS

There was a significant difference in maternal serum β-hCG concentrations regarding the histological stages of trophoblastic invasion. The serum β-hCG concentrations that the best predicted for stage III trophoblastic invasion was 6,475 mIU/ml, with a sensitivity of 100 %, a specificity of 92 %.

CONCLUSION

The depth of trophoblastic tissue infiltration into tubal wall is correlated with serum β-hCG levels, but not with gestational age. These findings may explain the reason for conservative management failure of EP in women with high β-hCG concentrations.

Human chorionic gonadotropin level as a predictor of trophoblastic infiltration into the tubal wall in ectopic pregnancy: a blinded study

OBJECTIVE

To determine the relationship between gestational age, tubal ultrasonographic diameter, and serum hCG levels and different stages of trophoblastic infiltration of the tubal wall in ectopic pregnancy.

DESIGN

Blinded prospective study.

SETTING

University-based clinic in Italy.

PATIENT(S)

Thirty-seven consecutive patients with an ampullary ectopic pregnancy.

INTERVENTION(S)

Laparoscopic salpingectomy.

MAIN OUTCOME MEASURE(S)

Gestational age, diameter of the tubal mass as determined by transvaginal ultrasonography. and hCG level on the day of surgery. Ectopic pregnancy was classified according to the depth of trophoblastic infiltration: trophoblast limited to the tubal mucosa (stage I), extension to the tubal muscularis (stage II), or complete tubal wall infiltration up to the serosa discontinued by trophoblastic cells (stage III).

RESULT(S)

Fifteen patients (40.5%) had stage I tubal infiltration, 14 (37.8%) had stage II infiltration, and 8 (21.6%) had stage III infiltration. Gestational age and diameter of the tube did not differ among the three groups. The median hCG level was 1,710.5 mIU/mL (range, 113-5,635 mIU/mL) for patients with stage I infiltration. 4,690.0 mIU/mL (range, 150-21,531 mIU/mL) for patients with stage II infiltration, and 15,700.0 mIU/mL (range, 13,809-21,650 mIU/mL) for patients with stage III infiltration. All the patients with hCG levels > 6,000 mIU/mL had stage II or III invasion.

CONCLUSION(S)

These findings may explain why the conservative treatment of ectopic pregnancy is less successful in patients with high hCG levels than in patients with low levels. Use of radical procedures may be justified in the former group.