Table 1. Clinical, ultrasonographic, and histopathological features aiding in the differentiation between angiolipoma and Lipedema Dermal and Hypodermal Classification 3 nodules.

Data summarized from references [7-14].

Abbreviations: DHJ, dermal-hypodermal junction; LDHC, Lipedema Dermal and Hypodermal Classification.

Characteristic	Angiolipoma	Hyperechoic Nodule in Lipedema (LDHC 3)
Etiology	Benign adipocytic neoplasm	Focal hemorrhage
Pathophysiology	Uncertain	Hypoxic-ischemic alterations in inflammatory-fibrotic tissue, neovascularization, and capillary fragility
Location	Trunk and extremities	Areas affected by lipedema (thighs, arms, and legs)
Pain	Painful on palpation	Focal and intense pain
Ultrasound	Hyperechoic oval or round-shaped nodule with well-defined borders	Hyperechoic focus with variable margins; may show subtle posterior acoustic shadowing or an internal anechoic area, depending on the stage of hemorrhage. Irregular DHJ, bulging deep hypodermis, and irregular septa with rupture predominantly in the superficial hypodermis
Capsule on ultrasound	Rare	Absent
Vascularization (Doppler)	Frequently absent or with a few vessels	Absent or minimal peripheral flow
Histology	Mature adipocytes with capillary proliferation containing fibrin microthrombi	Hemorrhage with hemosiderin deposition; steatonecrosis; inflammatory infiltrate (eosinophilic granular content and histiocytic reaction)
Hemorrhage	Absent	Present
Hemosiderin	Absent	Present