Vasculitis involving the breasts

A 69-year-old woman came to our hospital with fever for one week and abdominal pain. She had a negative PCR test for COVID-19 ordered by her attending physician. Routine laboratory tests were suspicious of infection (C-reactive protein, leucocytosis and neutrophilia). Examination revealed lumps in both breasts. As antecedents only highlight arterial hypertension.

During admission, the patient underwent CT of the abdomen (Figure 1) and lumbar spine MRI (Figure 2) with normal findings.

The gynaecologist performed a clinical breast examination that concluded redness in both upper outer quadrant of breasts with an underlying tender left mass of 1x1cm. Enlargement of left axillary lymph nodes was also seen. Prior screening mammogram (2 years-ago) was BI-RADS 1 (Figure 3 a,b,c,d).

A new mammography was ordered with no suspicious findings: fatty breast density and BI-RADS 1 (Figure 4  a,b,c,d). An ultrasound was targeted to the focal palpable abnormality revealing ill-defined increased echogenity with no definite mass lesion. Perivascular fat infiltration along a vessel (Figure 5a) with no evidence of thrombosis on color Doppler sonography was noticeable (Figure 5b). Lymph nodes were also present (Figure 5c). Core biopsy using a 14-gauge needle in the palpable upper outer quadrant was performed. On histological examination, the biopsied tissued revealed nongranulomatous vasculitis involving medium-sized vessel. A diagnosis of vasculitis involving the breasts was established, compatible with polyarteritis nodosa. Additional tests for excluding systemic involvement were performed, which revealed negative results (Figure  6). She is been treated with prednisone and methotrexate, improving in local and systemic symptoms one year later.

Vasculitis is defined as inflammation of the blood vessel walls. Vessel-inflamation involves different types of illnesses and prompt treatment is crucial and life-saving. [1,2].

Breast vasculitis may present as an isolated finding or in the context of systemic illness [1,3,4,5].The diagnosis of isolated or single-organ vasculitis is made when evidence of similar disease elsewhere is not proven. Moreover, continued surveillance has to be done to ensure it is not the first sign [1,6]. In the cases of systemic vasculitis, breast may be the initial presentation or appear later [1,2].

Breast involvement alone is not frequent. The vast majority presents extramammary manifestations such as myalgia, arthralgia, headache, rash, cough, and hematuria [5,7]. Patients with systemic vasculitis may have other constitutional symptoms including fever, weight loss or fatigue [1,2,5].

The reported cases mostly are postmenopausal elderly women [1,2,5,6]. The patients present typically with a breast mass, most often tender and painful, for few weeks to several months and bilateral involvement is more common  [2,7,8].

Mammography and ultrasound of the breast are not specific for the diagnosis. Mammograms show normal to increased dense mammary parenchyma. Ultrasound reveals skin thickening, lesions with or without calcifications or hypoechoic mammary parenchyma [5,7]. In some cases it can be seen an hypoechoeic circumferential vessel wall thickening (halo) which indicates oedema of the vessel wall [3,5].

Differentiation of breast vasculitis from malignancy is very important [2,3,5]. Rare inflammatory breast cancer or lymphoma may manifest as edema without definite mass formation [3].

The gold diagnostic criteria is made by the biopsy and pathology of the tissue [4,7]. Histologic examinations of biopsies reveal inflammatory cells infiltrating small and medium-sized vessels [4,7].

The main therapies for systemic vasculitis involving the breast are glucocorticoid and immunosuppressant [7]. In general, prognosis is good and most patients achieve remission within a few months of treatment [4,7].

In our case, the clinical presentation with fever and abdominal pain (probably indicating myalgias) did not help to suspect breast vasculitis. Systemic vague symptoms were more taken into account at the time of admission than physical exam. Correlation between clinical, radiological and histological findings is therefore crucial. Reviewing the CT images, breast and axillary findings could be observed (Figure 7).  The take-home message is that although breast involvement is rare, vasculitis involving the breast is a possible diagnosis in presence of clinical breast mass especially if it associates increased hiperechogenity on ultrasound without defined mass.