Myolipoma
Jonathan B. McHugh, MD
Key Facts
Terminology
Soft tissue neoplasm composed of mature adipose tissue and smooth muscle
Clinical Issues
Adults; peak in 5th-6th decade
Female predilection
Most occur in retroperitoneum, pelvis, inguen, and abdominal wall
Excellent prognosis
Microscopic Pathology
Mixture of mature adipose tissue and smooth muscle
Smooth muscle component is usually arranged in short fascicles
Adipose component consists of mature adipocytes
Scattered thin-walled vessels are often present but lack thick-walled muscular arteries
 Retroperitoneal myolipoma composed of an admixture of smooth muscle and mature adipose tissue imparts a sieve-like appearance. Most tumors have a predominance of smooth muscle, such as this case. |
 Some myolipomas, such as this pelvic tumor, have a predominance of mature adipose tissue. Note the regular distribution of adipose and smooth muscle, imparting a sieve-like appearance on low power. |
TERMINOLOGY
Synonyms
Extrauterine lipoleiomyoma
Benign mesenchymoma (nonspecific historical term)
Definitions
Soft tissue neoplasm composed of mature adipose tissue and smooth muscle
CLINICAL ISSUES
Epidemiology
Incidence
Rare
Age
Adults; peak in 5th-6th decade
Gender
Female predilection
Site
Most occur in retroperitoneum, pelvis, inguinal canal, and abdominal wall
Less often occurs in extremities (subcutaneous or deep)
Rare sites include eyelid, pericardium, tongue, breast, orbit, and intradural
Presentation
Often found incidentally
May present with painless or painful soft tissue mass
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
