•To review the common and uncommon locations of leiomyomas in the uterus and beyond •To discuss the imaging appearances of typical and atypical leiomyomas with emphasis on the role of MRI •To recognize the imaging findings of various types of degeneration and complications of uterine leiomyomas

Uterine leiomyomas are extremely prevalent disease occurring in more than 20% of women older than 30 years (1, 2). Their typical appearances at magnetic resonance (MR) imaging have been very well described(6,8,9). However, leiomyomas vary widely in appearance and may be confused with other gynecologic malignancies. Indepth knowledge of pathogenesis of degeneration and the clinical course helps us accurately diagnose leiomyomas with unusual appearances.

Classic imaging features of all types of uterine fibroids(8): Plain radiograph Fig. 1 Popcorn calcification within the pelvis may suggest the diagnosis of dystrophic degeneration of uterine fibroids. Ultrasound Ultrasound is choice of imaging modality to diagnose uterine fibroid and monitor its growth: Uncomplicated leiomyomas are usually hypoechoic, but can be isoechoic, or even hyperechoic compared to normal myometrium(3,8) Calcification is seen as echogenic foci with shadowing Cystic areas of necrosis or degeneration may be seen Venetian blind artifact or edge shadowing or dense posterior...

Uterine leiomyomas are the commonest gynecologic tumors and are usually benign(1). It is essential for the radiologists to be familiar with the typical and atypical imaging appearances of leiomyomas and its complications to make confident diagnosis and to exclude other ominous pathologies especially malignant gynecological tumours.

1: Buttram, V.C. Jr and Reiter, R.C. Uterine leiomyomata: etiology, symptomatology, and management. Fertil Steril. 1981; 36: 433–445, Link: https://www.fertstert.org/article/S0015-0282(16)45789-4/pdf 2: Walker, C.L. and Stewart, E.A. Uterine fibroids: the elephant in the room. Science. 2005; 308: 1589–1592, Link: https://www.fertstert.org/article/S0015-0282(07)00221-X/fulltext 3: Ferenczy, A., Richart, R.M., and Okagaki, T. A comparative ultrastructural study of leiomyosarcoma, cellular leiomyoma, and leiomyoma of the uterus. Cancer. 1971; 28: 1004–1018, Link: https://onlinelibrary.wiley.com/doi/pdf/10.1002/1097-0142(1971)28:4%3C1004::AID-CNCR2820280426%3E3.0.CO;2-M 4: Flake, G.P., Andersen, J., and Dixon, D. Etiology and pathogenesis of uterine leiomyomas: a review. Environ Health Perspect....