Teaching Case

A 59-year-old man, healthy, has a left breast nodule. The nodule has grown in the past year but with a great increase in the last two months. No breast pain, inflammatory signs, or nipple discharge. On clinical examination, a small, soft, and mobile nodule was detected in the inner lower quadrant of the left breast. No other relevant clinical information.

Because we have a focal breast complaint, international guidelines like those provided by the American College of Radiology and our institution's breast protocols recommend breast evaluation with mammography and subsequent targeted breast ultrasound for women and men. In younger women or men, the first line exam could be an ultrasound. In our patient, a man 59 years old, both exams were performed.

The breast ultrasound revealed a superficial solid mass/nodule in the inner lower quadrant of the left breast, heterogeneous, with slight vascularization on Power-Doppler, measuring 34 x 13 mm (Figure 1). No axillary adenopathies were found bilaterally or any other changes.

The mammogram revealed a well-defined oval lesion in the inner lower quadrant of the left breast, with high-density, heterogeneous, and no calcified (Figure 2). There are no calcifications or skin thickening. Right breast without any changes (Figure 3).

The imaging findings were consistent with a BI-RADS 4A, and the patient has been submitted to an ultrasound-guided needle-core biopsy Figure 4).

Background

Breast tumours in men are very rare and much less common than in women (100 times more common in women), so male breast tumours are a diagnosis that should not be missed [1]. Vascular tumours of the breast are very rare and a diagnostic challenge [2]. Breast haemangiomas constitute less than 1% of breast tumours, with only a few cases related in men, but the real incidence of male breast haemangiomas remains unclear [3]. It is important to differentiate it from other benign vascular tumours (lymphangioma and angiolipoma) or malignant vascular tumours (angiosarcoma) [4].

The exact pathogenesis of breast haemangiomas is unknown, but estrogens may be one of the causes, and they are characterized by the presence of dilated vessels [4]. Depending on the size of the vessels, breast haemangiomas are classified into 2 main types: cavernous and capillary. The cavernous type is the most frequent [5].

Breast haemangiomas tend to be larger in men than in women (5 cm mean in men and 1 cm in women), but the other radiologic findings are quite similar [6]. The differential diagnosis should include angiosarcoma, metastasis, breast cancer, and pseudoangiomatous stromal hyperplasia (PASH) [7].

Angiosarcoma is extremely rare but could mimic the appearance of breast haemangioma on mammography and ultrasound, with some clues on MRI, rapid enhancement and washout, and multiple unenhanced areas within the tumour [8]. Metastases to the breast are also extremely rare, and melanoma, non-Hodgkin’s lymphoma, lung, kidney, stomach, prostate, and ovary carcinomas are the most common primary malignancies that metastasize to the breast. Metastases are usually multiple, bilateral, without associated calcifications on mammography, with posterior acoustic enhancement on ultrasound in some cases, and isointense in T1 and T2 on MRI, with homogeneous enhancement [9]. Male breast cancer is rare and usually presents with irregular, spiculated, or indistinct margins on mammography and ultrasound, contrary to breast haemangiomas. PASH is a benign entity, found in 50% of male breast biopsies without specific imaging findings [10].

Clinical Perspective

Clinical signs are nonspecific, and generally, male haemangiomas are larger than women, presenting like a palpable mass or nodule [6]. Sometimes the patient could refer pain (depending on size), and discolouration of the overlying skin [6]. The tumour is usually superficial and rarely intraparenchymal [11]. Clinically it is impossible to have a diagnosis, so imaging and histology are essential to differentiate between a benign or malignant lesion [12].

Imaging Perspective

Imaging features of breast haemangioma are nonspecific, so imaging studies can be misleading in some cases, making it difficult to distinguish between vascular benign tumours and angiosarcomas [4–6]. On mammography, they are rounded or oval lesions, with well-defined and sometimes microlobulated margins, of high density or like the remaining fibro glandular tissue, almost always without calcifications [5,6,11]. On ultrasound, the eco pattern is variable (one-third hyperechoic and the remaining could be isoechoic, hypoechoic, or complex), with the absence of posterior acoustic shadow, and sometimes is possible to see vascularization on Colour-Doppler [5,6,13,14].

In our case, the patient refused to undergo resonance magnetic imaging (MRI), because he had previously suffered a severe panic attack and was not willing to undergo it again, despite the main advantages of carrying out the examination being explained, namely the possibility of this contributing to obtaining a diagnosis, which would make it unnecessary to perform a biopsy, which is a much more invasive and painful test. An alternative approach, but quite debatable, would be to carry out new checks every 4 to 6 months. If the lesion remained stable, it would probably be benign, and no other approach would be necessary. In a multidisciplinary meeting and having considered all hypotheses, it was decided to proceed with the biopsy to obtain a diagnosis, which would allow adequate treatment and follow-up. The MRI could be very useful, as the lesions are generally isointense on T1 about the remaining fibro glandular tissue, hyperintense on T2, with peripheral arterial enhancement, and delayed central enhancement, useful to differentiate it from malignant tumours [13].

Outcomes

Although generally asymptomatic, the excision is recommended to exclude the possibility of an underlying angiosarcoma and to avoid progression to that, despite of rare [5]. As previously mentioned, our patient underwent a biopsy, which revealed a cavernous haemangioma of the male breast. In accordance with the patient's wishes, it was decided to perform surgical resection of the lesion, which proceeded normally, without post-operative complications, and the lesion was completely excised. As it was a benign lesion, no additional treatments were necessary and the patient underwent control after a year with mammography and ultrasound, which did not reveal any changes, so he was discharged from our institution and subsequent controls will be carried out by his family doctor.

Take Home Messages / Teaching Points

Male breast haemangiomas are very rare and benign, with imaging characteristics very similar to those in women. As there are no pathognomonic imaging characteristics of these lesions, mammography is completely nonspecific and although MRI and ultrasound can provide us with some clues for the diagnosis, histology is essential for a correct diagnosis.

All patient data have been completely anonymized throughout the entire manuscript and related files.