Breast cancer-related chronic arm lymphedema is associated with excess adipose and muscle tissue.

BACKGROUND: Arm lymphedema is a common complication after breast cancer treatment. Although conservative treatment can be used to reduce swelling, treatment often fails, possibly due to chronic edema being transformed from lymph fluid to subcutaneous fat, a condition called nonpitting lymphedema. It is currently unknown if the excess volume is solely due to excess in fat. This study evaluated whether dual energy X-ray absorptiometry (DXA) could be used to estimate the excess fat, muscle, and bone tissue in patients with arm lymphedema. METHODS AND
RESULTS: Eighteen women with arm lymphedema were investigated. Measurements were converted to volume values and compared with values obtained using plethysmography (PG). Linear regression equations and correlation equations were used to compare the DXA and the PG techniques in regard to total volume and excess volume in the lymphedematous arm. DXA was used to estimate excess fat, muscle, and bone volume in the lymphedematous arm. Both DXA and PG provided similar total arm volume and excess volume measurements for the lymphedematous arm. The lymphedematous arm showed 73% more fat, 47% more muscle, and 7% more bone by volume in the lymphedematous arm.
CONCLUSIONS: Both excess fat and muscle volume contributed to the total excess volume in nonpitting arm lymphedema; excess soft tissue developed the first few years after breast cancer surgery. DXA can be used to identify patients with excess fat in their arms and thus unsuitable for conservative treatment and may be useful in estimating the amount of fat to remove in patients scheduled for liposuction.