Presentation
Vaginal bleeding.
Patient Data
Bulky uterus showing:
large right anterolateral uterine body fibroid showing cystic degeneration
right posterior wall hypercellular uterine fibroid eliciting high signal on T1 and T2 WI, with diffusion restriction and post-contrast enhancement
left uterine wall small interstitial fibroid eliciting low signal on T2 WI with no diffusion restriction or post-contrast enhancement
Pathology after excision showed fibroids with degeneration. No malignancy.
Case Discussion
The case demonstrates two types of uterine fibroids. The first type is the fibroid with cystic degenration, while the second is the hypercellular uterine fibroid.
Cystic degeneration of a leiomyoma is an uncommon type of uterine leiomyoma (fibroid) degeneration. When the leiomyoma increases in size, its vascular supply becomes inadequate and leads to different types of degeneration: hyaline, cystic, myxoid, or red degeneration. Dystrophic calcification may also occur. Hyalinization is the commonest type of degeneration. Cystic degeneration is an extreme sequelae of edema. On MRI, lesions contain internal cystic areas, as in this case.
Typical features of uterine fibroids include hypointense signal on T2, loss of diffusion restriction, and minimal contrast enhancement.
Hypercellular uterine fibroids represent an atypical type of fibroid. Pathologically they are soft, compact structures with increased cellularity, no collagen, and abundant blood vessel, yet with no dysplasia or malignancy. Radiologically, they appear of intermediate to high signal on T2, diffusion restriction, and avid homogeneous contrast enhancement.
The main differential is a uterine leiomyosarcoma which usually occurs in postmenopausal older females. They are usually poorly demarcated and show aggressive features, such as hemorrhage and necrosis with heterogeneous contrast enhancement and internal non-enhancing areas. Uterine leiomyosarcoma usually demonstrates diffusion restriction and markedly decreased ADC values.