Complications

• hyaline degeneration - the most common change observed in fibroids; the fibrous and muscle tissues are replaced by hyaline tissue
• cystic degeneration - usually after the menopause; due to liquefaction of areas of hyaline tissue
• red or carneous degeneration - an acute degenerative process caused by haemorrhage into the tumour; affects half of all fibroids during pregnancy
• fatty degeneration - usually at, or after, the menopause
• calcification - particularly after the menopause; usually preceded by fatty change. In advanced cases, the whole tumour becomes a calcareous mass - so called "womb stone"
• atrophy - occurs after the menopause; but large tumours may show only a small reduction in size
• torsion - produces severe pain
• secondary infection of a necrotic fibroid
• sarcomatous change - occurs rarely - studies have revealed an incidence of uterine sarcoma of about 0.2% in patients operated on for presumed fibroids (1,2)

Reference:

1. Obstet Gynecol. 1994 Mar;83(3):414-8.
2. Gynecol Obstet Invest. 1999;48(3):193-6.