Unenhanced axial T1-WI
Breast imaging
Case TypeClinical Cases
AuthorsWoussen Sofie, MD, Floris Giuseppe, MD PhD, Van Ongeval Chantal, MD PhD
Patient33 years, female
We report a case of a 33-year-old woman, known to have a germline BRCA2 mutation, in whom an enhancing breast nodule was detected on MRI during follow-up.
The small (diameter 5 mm), well-circumscribed nodule lying retroareolar in the posterior third of the right breast was isointense to muscle on the T1-weighted images and showed no diffusion restriction. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with fat suppression exhibited an initial increasing enhancement of the nodule followed by a plateau in the delayed phase (type 2 curve). The nodule was classified as BI-RADS 3 based on its imaging features. Three months later a control MRI was performed but no changes were observed, furthermore the lesion was not apparent on sonography. Due to the uncertainty about the lesion a MRI-guided vacuum-assisted biopsy was taken.
Histopathology showed a benign perilobular haemangioma, characterised by a conglomerate of dilated capillaries growing between the breast acini of a few terminal ductal-lobular units. The normal imaging follow-up, for BRCA2 mutation carriers, was continued.
Perilobular haemangiomas are microscopic vascular lesions of the breast (incidence 1-11%) [1-4]. They are benign and exist predominantly in the capillary form. As they may be small enough to be occult on imaging, they are often incidental findings [3, 4].
Due to their size (microscopically small), perilobular haemangiomas are only occasionally detected by imaging [3]. Mammographically detectable perilobular haemangiomas are oval, round or lobular in shape and well-circumscribed or microlobulated. Sonographically, they can appear as ill-defined hyperechoic or well-defined hypoechoic masses. DCE-MRI typically shows well-defined homogeneously enhancing lesions, demonstrating an intermediate signal on the T1-weighted images and an intermediate to high signal on the T2-weighted images [3].
Perilobular haemangiomas are small, mostly well-circumscribed, lesions consisting of a conglomerate of capillary-sized vessels that are lined by non-atypical endothelial cells. They can occur in the extralobular stroma and, despite their name, in the intralobular stroma [1, 3].
In young patients without a personal history of chronic lymphoedema or breast radiation therapy, as in our case, perilobular haemangiomas need to be differentiated from primary angiosarcomas; size is an important discriminator between them. Angiosarcomas are rarely smaller than 2 cm, whereas perilobular haemangiomas tend to be of microscopic size [1]. Angiosarcomas are cytologically atypical and mitotically active. They display an invasive and complex anastomosing growth pattern [3]. Perilobular haemangiomas on the other hand show no cytologic atypia, complex anastomoses or mitotic activity. They grow around the breast structures without invading them [2, 3]. The main imaging features of angiosarcomas in differentiating them from perilobular haemangiomas are their larger size and more rapid growth [3]. The differential diagnosis of perilobular haemangiomas also includes pseudoangiomatous stromal hyperplasia (PASH). PASH is characterised by pseudovascular spaces that are lined by CD31-negative (myo)fibroblasts instead of CD31-positive endothelial cells [3].
Since there is no evidence that perilobular haemangiomas are precursors of angiosarcoma and (extensive) imaging-guided biopsy is sufficiently reliable to rule out any malignant component; in the absence of radiologic-pathologic discordance, surgical excision of perilobular haemangiomas can be avoided and imaging follow-up of these lesions can be justified [1].
[1] Jozefczyk MA, Rosen PP. (1985) Perilobular hemangiomas and hemangiomas. The American Journal of Surgical Pathology 9(7):491-503. (PMID: 4091183)
[2] Brodie C, Provenzano E. (2007) Vascular proliferations of the breast. Histopathology 52(1):30-44. (PMID: 18171415)
[3] Sanders ME, Simpson JF, Cates JM. (2016) Vascular Lesions of the Breast. A Comprehensive Guide to Core Needle Biopsies of the Breast 667-685.
[4] Sebastiano C, Gennaro L, Brogi E, et al. (2017) Benign vascular lesions of the breast diagnosed by core needle biopsy do not require excision. Histopathology 71(5):795-804. (PMID: 28644513)
URL: | https://eurorad.org/case/15726 |
DOI: | 10.1594/EURORAD/CASE.15726 |
ISSN: | 1563-4086 |
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