MR imaging of lipoma arborescens of the knee joint.

Lipoma Arborescens in Childhood: A Report of Two Sisters

“…In contrast, PVNS, synovial hemangiomatosis, and lipoma are usually located in the infrapatellar fat pad of Hoffa. [1,10,[17][18][19] According to the clinical and radiological/laboratory examinations and the MRI findings, we concluded that LA was the correct diagnosis in our cases. Although we referred our patients to orthopedics department for surgical synovectomy aiming not only to establish LA diagnosis conclusively, but also to treat the disease, family didn't accept the surgical synovectomy.…”

“…It can also be observed during childhood, sometimes bilaterally. [7][8][9][10][11][12] The etiology of LA is unknown. We found no information in the literature about the genetic basis of LA.…”

“…There are some reports that have suggested trauma, chronic RA, and osteoarthritis (OA) in the etiopathogenesis. [1,5,10] Some authors suggest that LA may induce secondary OA. [3,12] Osteoarthritis is usually seen in advanced ages, but LA can be seen in any age group.…”

Orthopaedic Case of the Month: A Painless Right Knee Mass in a 55-year-old Woman

“…Macroscopically, lipoma arborescens has a frondlike appearance with numerous villous synovial proliferations of fatty yellow tissue. Villous lipomatous proliferation of the synovial membrane is characteristic of lipoma arborescens [16,25]. In addition, lipoma arborescens usually is associated with some clinical conditions, such as trauma, osteoarthritis, or other chronic inflammatory conditions [16,25], whereas a true intraarticular lipoma usually occurs de novo without a prior event.…”

“…In addition, lipoma arborescens usually is associated with some clinical conditions, such as trauma, osteoarthritis, or other chronic inflammatory conditions [16,25], whereas a true intraarticular lipoma usually occurs de novo without a prior event. The characteristic finding of lipoma arborescens observed on MR images is villous-like projections in the synovial lining with high signal intensity on T1-and T2-weighted images, which will saturate on fat-suppressed sequences [25], whereas intraarticular lipomas usually present as a diffuse or nodular lipomatous lesion in the knee. A well-differentiated liposarcoma is a low-grade sarcoma affecting predominantly middle-aged patients.…”