Uterine Leiomyomata (Fibroids, Myoma)

Introduction

• Description: A uterine leiomyoma is a benign monoclonal connective tissue tumor found in or around the uterus, which may be disseminated in rare cases.

• Prevalence: 50%–70% of women older than 50 years (one study has demonstrated a rate of more than 80% in African Americans older than 50 years). Leiomyomata account for approximately 30% of all hysterectomies.

• Predominant Age: 35–50 years or older.

• Genetics: Chromosome shattering and reassembly resembling chromothripsis (a single genomic event that results in focal losses and rearrangements in multiple genomic regions) has been documented in leiomyomata.

Etiology and Pathogenesis

• Causes: Unknown; considered to arise from a single smooth muscle cell (of vascular origin), resulting in tumors that are each monoclonal. Estrogen, progesterone, and epidermal growth factor are all considered to stimulate growth.

• Risk Factors: Nulliparity, early menarche, African Americans (4- to 10-fold increase in risk), increasing age, obesity, alcohol use, reduced vitamin D levels, high-fat or high-protein diet (proposed). The use of oral contraceptive or depot medroxyprogesterone acetate reduces the risk.

Clinical Characteristics

Diagnostic Approach