Granulomatous mastitis: changing clinical and imaging features with image-guided biopsy correlation

Objectives

To review clinical presentation, revisit patient demographics and imaging findings in granulomatous mastitis and determine the optimal biopsy method for diagnosis.

Methods

A retrospective study was performed to review the clinical presentation, imaging findings and biopsy methods in patients with granulomatous mastitis. Twenty-seven patients with pathology-proven granulomatous mastitis were included.

Results

The average age at presentation was 38.0 years (range, 21–73 years). Seven patients were between 48 and 73 years old. Twenty-four patients presented with symptoms and three patients were asymptomatic. Nineteen patients were imaged with mammography demonstrating mammographically occult lesions as the predominant finding. Twenty-six patients were imaged with ultrasound and the most common finding was a mass lesion. Pathological diagnosis was made by image-guided biopsy in 44 % of patients. The imaging features of granulomatous mastitis on mammography are infrequently described.

Conclusions

Our study demonstrates that granulomatous mastitis can occur in postmenopausal or asymptomatic patients, although previously reported exclusively in young women with palpable findings. Presentation on mammography as calcifications requiring mammographically guided vacuum-assisted biopsy has not been previously described. The diagnosis of granulomatous mastitis can easily be made by image-guided biopsy and surgical excision should be reserved for definitive treatment.

Key Points

? Characterizes radiographic appearance of granulomatous mastitis in postmenopausal or asymptomatic patients. ? Granulomatous mastitis can present exclusively as calcifications on mammography. ? The diagnosis of granulomatous mastitis is made by image-guided biopsy techniques.