Lupus Mastitis - rare but typical imaging findings

Clinical History

A 47 year-old female patient with a history of systemic lupus, underwent routine breast mammography and ultrasound.

Imaging Findings

A patient with induced menopause and a history of long-standing systemic lupus underwent routine ultrasound and mammography. On the mammograms there were diffuse heterogeneous calcifications (figure 1). Some calcifications were curvilinear and coarse, consistent with fat necrosis (red arrows). Breast density was diffusely increased bilaterally.
Compared to the preceding study (figure 2) there was a slight decrease in breast volume and progression of the calcifications. Ultrasound showed a few simple cysts as well as areas with posterior acoustic shadowing (figure 3) in association with fibrotic glandular changes and coarse calcifications.

Discussion

Lupus Mastitis is a rare clinical and radiological entity, occurring in 2-3% in patients with long-standing systemic lupus erythematosus. Kaposi first proposed the term “lupus panniculitis” in 1883 and 60 years later, Irgang introduced the term “lupus erythematous profundus” [1-3].

The pathophysiology of this entity is unknown but studies have demonstrated that lupus mastitis is an extension of the inflammatory process that involves the overlying skin (panniculitis) or may be the result of vasculitis [1, 2]. A correlation between traumatic procedures and the onset of this entity has also been described, so a conservative strategy in these patients should be advocated. Invasive procedures such as surgical or needle biopsy should be reserved for cases with atypical imaging findings [1, 4]. Some authors defend that the radiological and clinical features alone should suffice to diagnose lupus mastitis [2, 3].

Differential diagnoses include breast carcinoma, Hodgkin´s lymphoma, connective tissue disorders and other granulomatous mastitis. It is often the adequate clinical setting that is the main diagnostic clue [2].

Imaging findings such as dense coarse calcifications, increased fibroglandular tissue and decrease of breast volume due to fibrosis in patients with erythematous systemic lupus generally provide the diagnosis [1, 2].

This case should alert practioners to the right diagnosis while avoiding unnecessary biopsies or surgical procedures that may worsen the patient’s condition.

Differential Diagnosis List

Final Diagnosis

Lupus mastitis

URL:	https://www.eurorad.org/case/13346
DOI:	10.1594/EURORAD/CASE.13346
ISSN:	1563-4086