The patient is a 42-year-old woman, with no prior history of tuberculosis disease or tuberculous contact and no familial neoplasia history. She has five children and adopts a contraceptive device since 5 years ago after her last delivery.
The symptomatology has been evolving 3 months before her admission with the appearance of the right breast swelling. The gradual increase in the lesion volume was the chief complaint during her first consultation.
The clinical examination found a swelling of the right breast, extending to its outer half. It was associated with local inflammatory signs, nipple retraction, and mobile, homolateral, axillary lymphadenopathy, which measured about 2.5 cm. There was no nipple discharge. The patient had no infectious sites, and the infectious biology check-up was strictly normal. An initial ultrasound mammogram found lesions of the supero-external quadrant of the right breast, classified ACR 4 (Breast Imaging Reporting and Data System of American College of Radiology), and the patient was given an antibiotic therapy based on fluoroquinolone 200 mg, twice daily for 8-10 days.
After 7 days of treatment, a cutaneous fistulization appeared and the inspection of the breast found a clinical sign described as "orange peel," resulting from pus to the skin (Figure 1). Then, an additional magnetic resonance imaging (MRI) was requested. The MRI found a lesional range made of multiple oval formations, occupying the entire gland and extending to the skin (Figure 2). The comparison of their fluid signal to the control ultrasound images led to the possibility of an IGM (Figure 3).
Histology, performed on three biopsy cores ranging in size from 5 to 14 mm long, found no signs of malignancy or pathogen on the samples. It showed a fibrous breast parenchyma with a polymorphic inflammatory infiltrate and decentered epithelio-gigantocellular granulomas of caseous necrosis (hematoxylin and eosin (HE) x10) in favor of IGM (Figure 4).
Further treatment was done by antibiotic therapy and wound dressings. The evolution was favorable with a regression of inflammatory signs and a progressive healing.
The long-term follow-up was as follows: the patient's checkups at 3 and 6 months were very satisfactory with a complete regression of the picture and a definitive healing of skin lesions. Because the patient missed the 12 months appointment, she had been called and reassured that she was in good clinical condition.