All of the following are the reasons for sudden onset of pain in an asymptomatic case of uterine fibroid, EXCEPT:

Mature or "old" leiomyomas are white but contain yellow, soft, and often gelatinous areas of hyaline change. These tumors are usually asymptomatic. Leiomyomata may cause pain when vascular compromise occurs. Thus, pain may result from degeneration associated with vascular occlusion, infection, torsion of a pedunculated tumor, or myometrial contractions to expel a subserous myoma from the uterine cavity. The pain associated with infarction from torsion or red degeneration can be excruciating and produce a clinical picture consistent with acute abdomen. Ref: Drinville J.S., Memarzadeh S. (2007). Chapter 39. Benign Disorders of the Uterine Corpus. In A.H. DeCherney, L. Nathan (Eds), CURRENT Diagnosis & Treatment Obstetrics & Gynecology, 10e.