Lipoma arborescens of the knee

Area of Science:

• Orthopedics
• Radiology
• Pathology

Background:

• Lipoma arborescens is a rare, benign intra-articular lesion characterized by synovial villous proliferation and subsynovial fat cell replacement.
• Its etiology remains unknown, making diagnosis challenging within the differential for chronic knee swelling.

Observation:

• This report details an exceptionally rare case of bilateral lipoma arborescens affecting both knees.
• The condition presented as a slowly progressive, chronically swollen knee, a common but often misdiagnosed symptom.

Findings:

• Histopathological examination confirmed the characteristic features of lipoma arborescens: villous hyperplasia of the synovium and diffuse infiltration by mature adipocytes.
• Imaging studies, such as MRI, are crucial for differentiating lipoma arborescens from other intra-articular pathologies.

Implications:

• This case underscores the importance of considering lipoma arborescens in the differential diagnosis of bilateral chronic knee swelling.
• Understanding the clinical presentation, diagnostic modalities, and treatment options is vital for effective patient management and improved outcomes.