Sonographic Appearance of Subcutaneous Angiolipomas

Abstract

Case ReportA 37-year-old man had multiple subcutaneous lumps on the torso and all extremities. These first became noticeable after puberty and had slowly increased in size and number over the years. They were variable in size, ranging from several millimeters to several centimeters. The lumps were firm, partially mobile, and smooth on palpation. The larger ones had a bosselated surface. Some were mildly tender on compression. Sonographic assessment of several of the larger lumps was requested before cosmetic surgery. The lumps were imaged with a high-resolution L12-5 linear array transducer on an HDI 5000 machine (Philips Medical Systems, Bothell, WA). These all had a similar appearance on sonography. The lumps were well defined and located in the subcutaneous layer. They had a predominantly hyperechoic appearance, which clearly distinguished them from the adjacent hypoechoic adipose tissue (Figure 1). Small, patchy hypoechoic areas were noted within the larger masses. No posterior acoustic enhancement was seen. The larger masses showed sparse internal vascularity on color Doppler imaging. Excisional biopsy of 16 lumps showed the typical features of angiolipomas, with a mixture of adipocytes and a variable amount of angiomatous tissue.

Sonographic Differentiation Between Angiolipomas and Superficial Lipomas

“…Although not frequent, internal vascularity was only seen in angiolipomas and not in superficial lipomas. The sonographic features of the angiolipomas in our study were similar to those found in previous studies 5 , 15 . The mixture of vessel structures with adipose tissue might also contribute to the heterogeneous echo texture, hyperechogenicity, and vascularity.…”

“…Angiolipomas are considered a variant of lipomas because they also have mature adipocytes with encapsulation. In addition to the features of lipomas, angiolipomas are also composed of a branching network of blood vessels, 7 , 14 specifically small‐caliber capillaries, and often contain fibrin thrombi with surrounding mature fat 6 , 15 . However, angiolipomas have a normal karyotype, unlike lipomas, which have karyotypic abnormalities.…”

“…In addition to the features of lipomas, angiolipomas are also composed of a branching network of blood vessels, 7,14 specifically small-caliber capillaries, and often contain fibrin thrombi with surrounding mature fat. 6,15 However, angiolipomas have a normal karyotype, unlike lipomas, which have karyotypic abnormalities. As such, angiolipomas are also considered reactive or hamartomatous lesions and not true tumors.…”

Accuracy of Sonographic Diagnosis of Superficial Masses

“…Sonography is an attractive modality for evaluating superficial masses because of its availability, lack of radiation, lower cost, and higher resolution compared with magnetic resonance imaging. The sonographic appearance of superficial masses has been described by multiple authors, 2 , 4 – 6 and lipomas are known to have variable echogenicity ranging from hyperechoic to hypoechoic compared with skeletal muscle. The diagnostic accuracy of sonography in the evaluation of superficial masses remains controversial, with some authors reporting low diagnostic accuracy and urging caution 4 , 7 .…”

Ultraschalldiagnostik der Hand

“…Sie sind meist in der Handfläche vorzufinden und können aufgrund des weichen, indolenten Palpationsbefunds klinisch relativ einfach diagnostiziert werden. Daneben können auch andere mesenchymale Elemente (fibröse, chondroide, myxoide, Angiolipome) enthalten sein, was die sonografische Untersuchung erschweren kann (Choong 2004). Abb.…”