Idiopathic Granulomatous Mastitis Associated with Erythema Nodosum

Abstract

Background: Idiopathic granulomatous mastitis (IGM) is an uncommon benign chronic inflammatory breast disease, and erythema nodosum (EN) is an extremely rare systemic manifestation of IGM. Here, we report a rare case of IGM accompanied by EN.

Case report: A 32-year-old patient was admitted to our clinic with a history of a tender mass in the right breast. On physical examination, the right breast contained a hard, tender mass in the lower half with indrawing of the nipple. She had florid EN affecting both legs. She was evaluated with mammography, ultrasound, power Doppler ultrasound, non-enhancing magnetic resonance imaging (MRI), dynamic contrast-enhanced MRI, fine needle aspiration biopsy (FNAB) and excisional biopsy. Time-intensity curves showed a type II pattern on dynamic contrast-enhanced MRI, which has an intermediate probability for malignancy. The FNAB reported a benign cytology suggestive of a granulomatous inflammation, which was also supported by the histopathological findings. A partial mastectomy was performed following medical treatment. There was no recurrence at 1-year follow-up.

Conclusion: IGM should be considered in the differential diagnosis of EN. Although histopathological examination remains the only method for the definite diagnosis of IGM, MRI can be helpful in the diagnosis or differentiation of benign lesions from malignant ones.

Keywords: Breast cancer; erythema nodosum; fine needle aspiration biopsy; idiopathic granulomatous mastitis; magnetic resonance imaging; ultrasonography.

Figures

FIG. 1.

Erythema nodosum affecting both legs

FIG. 2.

Ultrasound and power Doppler imaging of lesion demonstrated 3.5×1.2-cm hypoechoic vascular mass with irregular lobulated contour

FIG. 3.

a–d. Asymmetrical tissue of low signal intensity on the lateral aspect of the right breast is seen on axial pre-contrast T1-weighted (W) image (a), on axial T2-W fat-saturated image, the lesion is seen as hyperintense (b). Sagittal (c) and axial (d) T1-W subtraction images showed heterogeneously enhancing areas with hyperintense nodular enhancements.

FIG. 4.

a–c. Contrast-enhanced T1-weighted, fat-saturated, gradient-echo image shows regional heterogeneous enhancement (a), color-coded map shows foci with the maximum slope of enhancement increase (green) after contrast material injection, the foci were selected as regions of interest (b), dynamic signal intensity time graph (c). Curve indicates plateau enhancement. The vertical axis indicates the percentage of enhancement, and the horizontal axis indicates the time in minutes. A Type II curve has an intermediate probability for malignancy.

FIG. 5.

Photomicrograph of tissue specimen. Note the presence of non-necrotizing granulomatous inflammation with epithelioid histiocytes, lymphocytes, plasma cells, polymorphonuclear leukocytes and multinucleated giant cells (hematoxylin and eosin × 100).