Clinical History
A 69-year-old woman, asymptomatic, taken from a screening program.
Imaging Findings
The screening mammography shows a new appearance of multiple bilateral nodules, greater than 2 cm, superficially located within subcutaneous tissues. Morphologically they are oval and round, well-circumscribed, isodense and some of them with small hypondense areas within. The evaluation was completed with US and MRI. The US showed multiples nodules, oval and round with homogeneous hyperecoic echotexture and well-circumscribed, without posterior acoustic enhancement or shadowing. The MRI evaluation of both breasts showed the multiple nodules that appeared mildly hypointense on T1, hyperintense on T2 and with heterogeneous enhancement with contrast.
Physical examination showed no palpable and painless nodules, no skin thickening, skin or nipple retraction, or erythema. No axillary adenopathy was found and the patient did not have a history of trauma.
A core biopsy was performed of both greater nodules, with the final diagnostic of angiolipomas.
Discussion
Howard-Helwig described angiolipomas as an entity in 1960 [1]. Angiolipomas are unusual benign vascular and fat-containing tumours with a mixture of adipocytes and a variable amount of angiomatous tissue [1-3, 5]. Hystologically it represents a variant of lipoma, accounting for 5–17% of all benign fatty tumours [1, 2, 4]. There are two varieties of angiolipoma, the infiltrative and the noninfiltrative types [2-4], both are benign without malignant potential [2, 3]. Breast angiolipomas have been reported to be of the noninfiltrative variety [1, 2]. The patologic hallmark of an angiolipoma is scattered microthrombi in small blood vessels [1-3]. Angiolipomas are more commonly found in men and involving subcutaneous tissues [1, 2, 4, 5] of trunk and extremities, particularly the upper limbs, uncommonly arise in the breast [1, 2] where they are typically painless [1, 5]. There are usually no overlying skin changes [1] but there may be faint skin discoloration [2]. They may manifest as solitary or multiple [1, 4] synchronous or metachronous breast masses [1]. Angiolipomas generally occur sporadically, although a familial history has been reported in about 10% of cases [4].
There is no characteristic imaging finding of an angiolipoma of the breast [1, 2], its variable appearance overlaps with those of other benign and malignant lesions [2]. Mammography often shows a solid mass well or ill-defined, rarely greater than 2 cm in diameter [2] or an asymmetry with mixed densities (soft-tissue density interspersed with fat density) as seen in our case, but sometimes there are no findings seen on mammography [1]. Punctate calcifications have been reported [1, 5] representing intravascular hyaline thrombi [5]. US usually demonstrates a well-circumscribed iso or hyperechoic mass [1-5], but also may appear as ill-defined [1], with internal vascularity [2], sometimes with patchy hypoechoic areas in the larger lesions [2, 4]. As these imaging finding are not accurate, biopsy is essential for definitive diagnosis [2, 5], however, the US appearance is consistent with the finding that a homogeneously hyperechoic appearance with well-defined margins is a benign characteristic in breast masses [1].
Breast angiolipomas can be followed up with imaging [3] or treated as simple excision [1, 3, 4], although new lesions may develop [4]. For the infiltrative variety a wide excision may be needed to prevent recurrence [1].
In summary, angiolipoma is a rare vascular variant of the ordinary lipoma [1-3, 5], that should be included in the differential diagnosis of any well-defined and hyperechoic subcutaneous mass [4].
Differential Diagnosis List
Multiple bilateral angiolipoma of the breast.
Haemangioma
Hamartoma
Lipoma
Fat necrosis
Fibrosis
Malignancy
Final Diagnosis
Multiple bilateral angiolipoma of the breast.
