CASE 15726 Published on 16.06.2018

Perilobular haemangioma

Section

Breast imaging

Case Type

Clinical Cases

Authors

Woussen Sofie, MD, Floris Giuseppe, MD PhD, Van Ongeval Chantal, MD PhD

University Hospitals Leuven Belgium
Patient

33 years, female

Categories
Area of Interest Breast ; Imaging Technique MR, RIS
Clinical History

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.

Imaging Findings

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.

Discussion

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].

Differential Diagnosis List
Histopathology showed a benign perilobular haemangioma
Pseudoangiomatous stromal hyperplasia (PASH)
Angiosarcoma
Final Diagnosis
Histopathology showed a benign perilobular haemangioma
Case information
URL: https://eurorad.org/case/15726
DOI: 10.1594/EURORAD/CASE.15726
ISSN: 1563-4086
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