CASE 2704 Published on 22.10.2005

Bilateral theca lutein cysts associated with hydatidiform mole: MR findings

Section

Genital (female) imaging

Case Type

Clinical Cases

Authors

Bexiga A*, Cunha TM*, Penedo JP*, Oliveira C*, Tomé V** *Department of Radiology **Department of Medical Oncology

Patient

21 years, female

Categories
No Area of Interest ; Imaging Technique MR
Clinical History
A 21-year-old female patient was investigated for a sero-hematic vaginal discharge, a positive pregnancy test and the presence of bilateral adnexal masses.
Imaging Findings
The patient had been experiencing dysmenorrhea for the past two months, with hypertension and oliguria. She underwent a pregnancy test which was positive and an abdominal ultrasound that suggested a molar pregnancy. The histological examination of the material obtained by suction curettage revealed complete hydatidiform mole (Fig. 1). She was admitted to our hospital for further diagnostic and treatment evaluation, as she also had a dry cough, dyspnea, palpitations and dizziness. The physical examination revealed polypnea, a prominent abdomen and the presence of a palpable lump located in the hypogastrium and the left iliac fossae. This lump had an elastic consistency and was painless. She also had a sero-hematic vaginal discharge. The laboratory blood tests revealed a Hb level of 7.48 g/dl and a ß-HCG >200,000 UI. A chest X-ray showed a diffuse bilateral interstitial infiltrate and a small bilateral pleural effusion (Fig. 2). The chest abormalities were assumed to represent pulmonary edema, and disappeared after support treatment. An abdomino-pelvic MR scan was performed and the T2W images revealed a small homogeneous hepatic enlargement, mild ascitis; a uterine enlargement (the uterus measured 16 × 7 × 9 cm), a distortion of the normal zonal anatomy without focal changes in the myometrium, the presence of heterogeneous contents in the endometrial cavity, and a marked enlargement of the ovaries, containing multiple theca lutein cysts (Fig. 3a–e). On contrast-enhanced T1-weighted images, there was a homogeneous enhancement seen in the myometrium and the uterine cervix (Fig. 3f, g). Considering the persistent elevated ß-HCG levels, she was submitted to chemotherapy (6 cycles with methotrexate). After this the ß-HCG levels returned to normal and there was an improvement in her clinical condition. One year later, she is well and without disease.
Discussion
GTD is a proliferative process that results from an aberrant fertilization. GTD may occur in a benign form (hydatidiform mole) or as a malignancy (invasive mole or choriocarcinoma). GTD is characterized by an abnormal proliferation of pregnancy-associated trophoblastic tissue with malignant potential. Complete moles are associated with the absence of a fetus, whereas partial moles usually occur with an abnormal fetus or may be associated with fetal demise. Pregnancy-induced hypertension can occur before 24 weeks of gestation. In 25%–60% of the cases of hydatidiform mole, the ovaries are seen to contain multiple theca lutein cysts, resulting from ovarian hyperstimulation due to high circulating levels of ß-HCG. These cysts are multiloculated, often bilateral, and resolve after treatment of the intrauterine process. Complications such as hyperthyroidism, anemia, and CID can occur. All patients should be screened for coagulopathy. An occurrence of trophoblastic embolism is believed to cause acute respiratory insufficiency. Once the diagnosis has been confirmed, the patient should be evaluated for metastatic disease and the molar pregnancy should be terminated. 15% of women with a complete mole will develop recurrent disease in the form of an invasive mole or choriocarcinoma. The mole, although evacuated, may persist and remain confined to the uterine cavity, penetrate the myometrium, embolize to the vagina or lungs, or transform into a choriocarcinoma. In most patients with complete moles, adequate evacuation is curative and vacuum aspiration is recommended as the initial method to avoid the dangers of perforation. In recent years, an earlier administration of chemotherapy has been found to reduce the incidence of metastases. A transabdominal sonography is of value when gestational trophoblastic disease is a diagnostic consideration. The complete hydatidiform mole has a classic sonographic appearance of a solid collection of echoes with numerous anechoic spaces. The ultrasound technique has not been shown to be useful in staging or in determining the patient's risk of developing persistent disease. Endovaginal sonography reveals the presence of multiple anechoic channels and spaces which are typically seen with trophoblastic disease. A color-Doppler endovaginal imaging procedure showed high-velocity blood flow, with a low-impedance system, through most of these spaces. Importantly, the color-Doppler imaging disclosed the presence of vascular invasion of the myometrium. CT is the imaging procedure of choice to search for metastases (especially for lung metastases). MR imaging should be used when the use of a contrast medium is contraindicated, follow-up studies are needed, or when the uterus is to be evaluated as the site of primary disease. It is also indicated as a technique to search for a local myometrial or pelvic invasion. A hydatidiform mole usually appears as a heterogeneous, markedly hyperintense mass on T2-weighted images, that distends the endometrial cavity. On contrast-enhanced T1-weighted images, characteristic numerous cystic areas are seen in the mass. The normal myometrium remains and surrounds the mass. Intralesional hemorrhage and necrosis are also typical occurrences, and both would be expected to cause areas of high-intensity signal within the tumor, on MR images. MR imaging is useful in tumor detection when the tumor deeply invades the myometrium but does not extend to the endometrial surface. In this situation, uterine curettage specimens are nondiagnostic. During chemotherapy, imaging studies are requested only when HCG concentrations plateau or rise unexpectedly. The reappearence of uterine zones, a decrease in myometrial and adnexal vascularity, and a development of intralesional hemorrhage and/or necrosis paralleled the decreases in serum ß-HCG levels, during favourable therapeutic response.
Differential Diagnosis List
Complete hydatidiform mole.
Final Diagnosis
Complete hydatidiform mole.
Case information
URL: https://www.eurorad.org/case/2704
DOI: 10.1594/EURORAD/CASE.2704
ISSN: 1563-4086