Hemorrhage from intramural leiomyoma during pregnancy

Clinical History

This report describes the MRI findings in a in a 38-year-old woman with known uterine leiomyomas complicated by haemorrhagic degeneration during pregnancy.

Imaging Findings

A 38-year-old primiparous woman was referred for an MRI of the pelvis and lower abdomen. She was in her 26th gestational week and had been under prior surveillance for multiple large uterine leiomyomas. Presently, she complained of a dull pain in the left lower quadrant. The course of the pregnancy had been hitherto uneventful. Transabdominal ultrasonography performed at the obstetrics department showed a new complex mass in the left anterior uterine wall, corresponding to the former location of a known leiomyoma. Coronal and transverse T1-weighted and 3-plane T2 weighted native MR images of the uterus were obtained on a 1.5 T multichannel MR scanner with a 8-channel pa surface coil. Coronal T2-weighted images (Fig. 1) showed two large hypointense intramural leiomyomas situated left to the amnion cavity. The more caudally located lesion was surrounded by a large rim of haemorrhage appearing bright on T1- and T2-weighted images (Fig. 1, 2). There was also a more recent bleeding component leading to T2-dephasing (Fig. 1b). The leiomyomas showed no relation with the placenta and there were no extrauterine or intraperitoneal fluid collections. During intensified ultrasound surveillance, the bleeding did not increase in size and the pain subsided gradually. At gestational week 37, the patient delivered a healthy baby without any further complications.

Discussion

Uterine leiomyomas, also termed fibroids, are the most frequent tumours in women of reproductive age, occurring in up to 30%. Consequently, they are also commonly found in pregnancy. Their true incidence during pregnancy is, however, unknown; reported rates vary from 0.1% to 12.5% [1]. In spite of a presumably high incidence, acute complications resulting from leiomyomas, are quite rare. Haemorrhagic (red) degeneration seems to be a hormone-dependent condition, that occurs characteristically, but not exclusively in pregnancy [2,3]. It has also been observed in patients under oral contraceptives or gonadotropin releasing hormones [4]. Haemorrhagic infarction of the leiomyoma is considered as the probable pathogenetic mechanism [5]. Red degeneration of a leiomyoma during pregnancy may be a rare cause of abdominal pain or fever [2]. The presence of leiomyomas may affect pregnancy and delivery in several ways. Size, location, and number of the lesions and their relation to the placenta are critical factors. However, in a large case-control study performed by Vergani and co-workers, the incidences of preterm delivery, premature rupture of membranes, in utero growth retardation, placental abruptio, placenta previa, postpartum haemorrhage, and retained placenta were not significantly higher than in the general population [6]. Since haemorrhagic complications resulting from leiomyomas are often self-limiting, it is important to familiarise with the MR imaging appearance of red degeneration and to distinguish it from other significant diseases or pregnancy complications. Histologically, several types of degeneration can occur in a leiomyoma. The common types include hyaline (>60% ), cystic (approximately 4%), myxoid, and red. Necrosis, and calcification may also be observed [7]. An irregular, T1-hyperintense rim around a centrally located myoma seems to be the most reliable MR imaging sign of haemorrhagic (red) degeneration [8]. During pregnancy, treatment options of complicated leiomyomas are limited. However, with appropriate surveillance and supportive management, successful delivery can be expected in most cases. Myomectomy at the time of a caesarean section is associated with significant morbidity and should be performed only in selected patients. Definitive treatment of uterine leiomyomas can nearly always be postponed until postpartum [2].

Differential Diagnosis List

Final Diagnosis

Haemorrhagic (red) degeneration of uterine leiomyoma during pregnancy.

URL:	https://www.eurorad.org/case/8209
DOI:	10.1594/EURORAD/CASE.8209
ISSN:	1563-4086