Navigating obstetric enigma: Placenta accreta spectrum masquerading as gestational trophoblastic neoplasia

Introduction

Placenta accreta spectrum (PAS) is a formidable obstetric complication often associated with previous Caesarean section (C). Despite hysterectomy being the standard treatment, certain cases prompt consideration for conservative management. However, complications lead to hysterectomy in 70% cases, with intervention occurring within a median time of 30 days post-delivery.^1–4 Ours is a report of two cases where PAS was not promptly communicated, and resulted in delayed recognition during conservative management, mimicking the presentation of gestational trophoblastic neoplasia.

Case report 1

A 33-year old woman, para five, presented with heavy menstrual bleeding for ten days after her second C, performed 19 months earlier. Although she resumed regular menstrual cycles five months postpartum, her experience was marred by severe continuous bleeding, accompanied by fever. Her haemoglobin level precipitously dropped from 112 to 62 g/L, and examination revealed an enlarged and tender uterus with a foul-smelling discharge mixed with blood. Ultrasound and MRI revealed a lobulated mass with tortuous vascular channels invading the left lateral uterine wall, resembling gestational trophoblastic neoplasia (Fig. 1A), further suggested by raised serum β-hCG levels at 60.8 IU/L. A mere 72 h later, torrential haemorrhage ensued, necessitating an emergency abdominal hysterectomy.

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Figure 1.

(A) Contrast-enhanced MRI images of the uterus showing the placenta invading into myometrium with a lot of dilated vascular channels. (B) Cut section of the uterine specimen shows an adherent placenta.

Intraoperatively, placental tissue was found adherent to deep layers of the myometrium on the left lateral side, confirming PAS (Fig. 1B). Histopathology validated the diagnosis, and postoperatively, the patient experienced a high-grade fever managed with antibiotics, eventually being discharged on day 12. The lack of timely communication regarding the presence of PAS during the antenatal period and delayed recognition during conservative management mimicked the challenges often seen in gestational trophoblastic neoplasia.

Case report 2

A 27-year old gravida 2 woman, who had had a previous C 22 months earlier, presented with recurrent bleeding following two months of amenorrhoea. After an initial episode of bleeding, an ultrasound scan revealed retained products of conception, and β-hCG levels were elevated at 500 IU. Suction and evacuation were performed, followed by a period of amenorrhoea. Subsequently, misoprostol was administered, leading to further bleeding, following which the patient was referred to us. At examination, the uterus was enlarged up to 20 weeks’ gestational size. An MRI scan revealed a large vascular mass in the lower uterus invading the anterior and posterior myometrium, closely mimicking the appearance of gestational trophoblastic neoplasia (Fig. 2A). Computed Tomography angiography showed a lesion distending the lower aspect of the uterus with tortuous bilateral uterine arteries and fistulous communication with draining veins (Fig. 2B). A provisional diagnosis of placental site trophoblastic tumour was considered owing to persistently raised β-hCG levels.

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Figure 2.

(A) Contrast-enhanced MRI of the pelvis showing an enlarged lower segment of the uterus. (B) CT angiogram of the pelvis showing a highly vascular lower segment of the uterus. (C) Intra-operative picture of the uterus with distended lower segment of the uterus.

At laparotomy, the lower segment of the uterus was notably enlarged (Fig. 2C). A total hysterectomy with preoperative uterine artery embolisation was performed without complication. Histopathology revealed ghost villi lined by trophoblastic cells invading the myometrium without intervening decidua, echoing the deceptive nature of gestational trophoblastic neoplasia. The silent threat of PAS, unnoticed during the previous C, unfolded unbeknownst to the patient.

Discussion

PAS presents a diagnostic challenge, especially when mimicking the presentation of gestational trophoblastic neoplasia. According to International Federation of Gynaecology and Obstetrics guidelines, a conservative approach is considered for fertility preservation, but effective communication and timely intervention, if required, is obligatory. ⁵ In both instances described, proper communication was lacking, resulting in delayed and emergency intervention, equivalent to managing gestational trophoblastic neoplasia de novo.

Previous studies have explored planned conservative management of PAS. ⁶ One case out of 17 required emergency hysterectomy owing to massive intra-operative bleeding. A further five had a hysterectomy secondary to haemorrhage and sepsis.

The ‘uterine artery ligation with clover suture’ technique has been introduced in conservative management, significantly reducing blood loss, but requiring more surgery time and expertise. ⁷

The association between conservative treatment for PAS and subsequent gynecological and fertility showed no evidence of fertility impairment post-conservative treatment, ⁸ although women in the PAS group required more postpartum operative procedures.

Conclusion

Our case reports shed light on the intricate nature of managing PAS when it mimics gestational trophoblastic neoplasia. Delayed complications emphasise the need for proactive measures in communication, patient education, and meticulous follow-up.