Acute pulmonary embolism caused by enlarged uterine leiomyoma: A rare presentation

Background

Pulmonary embolism (PE) is a life-threatening condition occurring about 23–69 patients per 100 000 population. It can range from an asymptomatic patient to a massive PE. The implementation of its appropriate treatment at presentation is usually effective and life-saving. PE is also recognized in about 50% of patients with deep venous thrombosis (DVT) and nearly 80% of those who are being diagnosed with PE have DVT [1–3].

Some main predisposing factors, either acquired or inherited, of DVT and the resultant PE include deficiencies of blood coagulation agents, immobilization, hypercoagulable states caused by cancer, pregnancy, trauma, oral contraceptives, and major surgery [2]. A rarely reported cause for developing thromboembolism is uterine leiomyoma contributing to pelvic venous compression, and thus the occurrence of PE in some cases [4].

We present a rare case of DVT and subsequent massive PE caused by a huge uterine leiomyoma, which was treated without any complications.

Case Report

A 42-year-old, non-smoking, virgin woman presented to our institution with complaints of dyspnea and pleuritic chest pain since 2 days ago along with 2-month transient spotting. She had a history of leiomyoma since 5 months ago, and was hospitalized due to vaginal bleeding, and had been undergone therapy by a gonadotropin-releasing hormone (GnRH) agonist and medroxyprogesterone acetate, intramuscularly. To control her anemia, she was given oral ferrous sulfate. There was no relevant familial history of the same condition. On physical examination, she was anxious and tachypneic on admission, with body mass index of 24.7 kg/m2, body temperature 37°C, blood pressure 100/70 mmHg, heart rate 120 beats per min, respiratory rate of 24 breaths per min, and 96% oxygen saturation while breathing room air. Other findings included regular heart beat with a 2/6 systolic murmur in the left sternal border, clear lung sound, and a non-tender abdomen with a 20-week size uterus. There was no swelling in her lower limbs.

An electrocardiogram revealed a sinus tachycardia and inverted T waves in v1 to v3 and inferior leads. Hematologic testing revealed hemoglobin of 11.3 g/dL and other results were within normal limits. Coagulation factors were also unremarkable. A chest radiograph showed Westermark sign without pleural effusion. An ultrasound investigation revealed an acute DVT in the popliteal and superficial femoral veins of her left leg and an enlarged leiomyoma of the uterus. Thereafter, transesophageal echocardiography (TEE) demonstrated normal left ventricle systolic function, severe right ventricle enlargement, McConnell sign, moderate tricuspid regurgitation, severe pulmonary hypertension of 110 mmHg, and dilatation of the main pulmonary artery. In addition, a 2.6 1.6 cm echogenic mass was detected in the left pulmonary artery, consistent with thrombosis (Figure 1). Given her leiomyoma history, she underwent magnetic resonance imaging (MRI), which revealed a huge uterine-derived mass compressing both common iliac veins (Figure 2).

Due to massive PE, the patient was administered loading dose of 250 000 units of streptokinase and the infusion of 100 000 units per hour during 24 h. After undergoing thrombolysis, her general condition significantly improved, and then she underwent anticoagulation therapy. One unit of packed red blood cells was also transfused. Examination by TEE on the fourth day revealed the disappearance of the pulmonary artery thrombosis. After achieving a therapeutic range of international normalized ratio (range 2.0–3.0), she was discharged on warfarin 5 mg daily.

The patient was followed for 3 months and then evaluated again and examined using TEE and ultrasonography, which demonstrated normal findings. After withholding warfarin preoperatively, she underwent myomectomy instead of hysterectomy due to her uterus preservation. Warfarin therapy commenced again following surgery, and she was discharged in stable condition on warfarin therapy. Nine months after myomectomy, she was well, without evidence of thromboembolism.

Discussion

PE commonly originates from DVT and can rapidly result in death, although appropriate treatment can reduce the risk of mortality. Despite the increase in guidelines on this issue, the optimal therapy, including thrombolysis and catheter-based therapies, has remained unclear, and it seems that we should consider using other factors, including patient wishes, age, quality of life, and comorbidities for implementing proper therapy [2,5].

Uterine leiomyoma is the most common benign pelvic tumor in women over age 30. Some of its well-known acute complications are thromboembolism, torsion of subserosal pedunculated leiomyoma, urinary retention, and hemorrhage. It is usually asymptomatic; however, as it increases in size, symptoms may present due to compression of the surrounding anatomic structures, resulting in significant increase in the incidence of thromboembolism [4,6]. In cases with thrombosis, hysterectomy is the criterion standard treatment, but in patients who want to preserve their fertility, myomectomy provides a conservative option together with using inferior vena cava filters and anticoagulant agents [4].

In our literature review, we found some cases similar to ours, but there were some differences regarding presentations, etiologies, and implemented therapies due to patient condition. Among reported cases, lower limb DVT and PE were most commonly diagnosed, and anticoagulant associated with hysterectomy was the most-implemented therapy. Only 1 report stated that taking progesterone was the etiology of thrombosis. In addition, a vena cava filter was used upon either extensive lower limb or iliac vein thrombosis, and embolectomy was performed in 2 cases (Table 1).

Concurrent incidence of venous thromboembolism and uterine leiomyoma usually developed in women with no other known risk factors of thromboembolism, and most of them were accompanied by compressed pelvic veins, contributing to pelvic and/or lower-limb thrombosis, with the left leg more commonly affected. These conditions were usually treated using anticoagulation and/or thrombolysis along with hysterectomy [7]. However, 1 case has previously been reported in which DVT may have been caused by administering progesterone agents for controlling vaginal bleeding [8]. In addition, as previously known, the use of hormone replacement therapy is associated with the high rate of venous thromboembolism (both DVT and PE) in women [9].

In the present case, we used thrombolysis therapy, which resulted in thrombosis resolution. Given the patient’s condition and her virginity, delayed myomectomy was performed instead of hysterectomy. Furthermore, TEE was also used as a diagnostic tool for identifying suspected PE in this setting for the first time. It is reasonable to assume that the venous stasis caused by leiomyoma was the main cause of DVT and subsequent PE. Administration of medroxyprogesterone acetate may have been another precipitating factor in our case.

Despite the successful therapy and 1-year survival, some questions remain unanswered, including the optimal treatment of PE, the true indication of using vena cava filters, and the proper and safe treatment strategy to decrease the leiomyoma size in such patients. Further prospective studies and clinical trials are needed to clarify these findings.

Conclusions

DVT and subsequent PE caused by the compression of pelvic veins is a rare complication of leiomyoma of the uterus. Thrombolytic therapy associated with myomectomy can be considered in treating such cases, and TEE can be used for diagnosing suspected high-risk PE and prognostic assessment in this setting. We should pay much attention to the rare complications of uterus leiomyoma, including thromboembolism and the implementation of proper therapy based on patient condition.