Missed Misdiagnosis: A Ruptured Cornual Ectopic Masked as Missed Miscarriage

AUTHOURS: WATTHUHEWA DAMAYANTHA , HIRSI-FARAH SUAD , SINGARATHNAM KANDASAMY

 

1 GEORGE ELIOT HOSPITAL NHS TRUST, O&G, NUNEATON, UNITED KINGDOM . EP.0269

GEORGEELIOTHOSPITALNHSTRUST, O&G, NUNEATON, UNITEDKINGDOM. EP.0269

BACKGROUND

Cornual (interstitial) ectopic pregnancies account for 2–4% of all ectopics but are

disproportionately life-threatening due to their high risk of rupture and massive

haemorrhage. Sonographic misinterpretation as a missed miscarriage is a common and

dangerous diagnostic pitfall.

CASE SUMMARY

Clinical Presentation:

Patient: 32-year-old, gravida 2 para 1, at 7 weeks gestation.

Lower abdominal pain, vaginal bleeding.

Initial Ultrasound: Empty gestational sac (14 mm), no fetal pole → diagnosed as missed

miscarriage.

Planned Management: Opted for surgical management (SMM) under ultrasound

guidance.

Intraoperative Findings:

Failure to retrieve products of conception.

Resistance during curettage → concern for uterine perforation.

Emergency Laparoscopy:

Ruptured cornual ectopic pregnancy.

300 mL haemoperitoneum.

Cornual wedge resection performed.

Retrospective Ultrasound Review:

Eccentrically placed gestational sac.

Thin myometrial mantle (<5 mm).

Positive

“interstitial line sign

”

.

DICUSSION

Cornual ectopics often mimic intrauterine pregnancies, especially early on.

Common diagnostic errors include:

Assuming an empty sac is intrauterine.

Overlooking location relative to the endometrial stripe.

Surgical complications (e.g., perforation) may occur if diagnosis is missed preoperatively.

LEARNING POINTS

Cornual ectopic pregnancies may masquerade as missed miscarriage

Key sonographic features include:

Lateralised sac

Thin myometrial mantle

Interstitial line sign

Always reassess unusual or ambiguous ultrasound findings before proceeding with SMM.

Multidisciplinary readiness is vital to managing surgical emergencies in early pregnancy.

CONCLUSION

This case emphasises the diagnostic nuance required to differentiate cornual ectopics from early IUPs

or missed miscarriages. Meticulous ultrasound review and early suspicion can prevent mismanagement

and preserve fertility. Multidisciplinary coordination is essential to avoid maternal harm.

REFERENCES

1.Ackerman TE et al. Radiology. 1993;189(1):83–7.

2.Timor-Tritsch IE et al. AJOG. 1992;166(3):877–81.

3.RCOG Green-top Guideline No. 21: The Management of Early Pregnancy Loss (2023).

4.Jurkovic D et al. Ultrasound Obstet Gynecol. 2007;30(6):804–10