Chronic non-granulomatous mastitis with positive culture for Mycobacterium tuberculosis

Abstract

Objective: The objective of this study was to describe a case of chronic mastitis with multiple recurrences and positive
culture for Mycobacterium tuberculosis. Methods: The information for this case report was obtained via a consent form,
and the study was approved by the Research Ethics Committee of the Universidade Federal de Goiás HC/UFG – GO, with
CAAE number: 11983719.0.0000.5078. Results: Patient N.F.R., female, 59 years old, with systemic arterial hypertension,
dyslipidemia, and smoker. On July 2020, a hypoechoic, heterogeneous, lobulated mammary nodule was identified on the
left, measuring 2×1 cm in the ultrasound examination. A core biopsy was performed, whose histopathology (HP) showed
benign breast tissue, ductal ectasia, fibroadenosis, and lymphomononuclear inflammatory infiltrate with neutrophilic
exudation. On April 2021, the condition evolved with hyperemia, edema, mastalgia, and the presence of an abscess measuring 2×2 cm. She used several antibiotics (clindamycin, cephalexin, amoxicillin-clavulanate, ciprofloxacin, and trimethoprim-sulfamethoxazole), with partial improvement. New exacerbations of the condition and recurrent fistulization
were presented. The secretion of the drained abscess on January 2022 showed negative bacilloscopy and growth of multisensitive Proteus mirabilis, treated with amoxicillin-clavulanate. After 2 months, the infection control service received
a culture for mycobacteria positive for the M. tuberculosis complex in breast secretions. The patient was summoned for
an infectious disease consultation, and treatment with rifampicin, isoniazid, pyrazinamide, and ethambutol (RIPE) was
initiated. A new drainage of the abscess was performed, and after 20 days of RIPE, the patient’s pain improved and the
fistula healed, maintaining an area of hyperemia and nodulation. She maintains treatment with the infectology and mastology team. Conclusion: The diagnosis of breast tuberculosis is challenging, and it depends on high suspicion, accurate
collection of biological materials and sending them for microbiological study in a timely manner. The culture is still the
gold standard, but it has low sensitivity in paucibacillary forms. HP, on the contrary, may not present tuberculoid granuloma. In this sense, the rapid molecular test for mycobacteria could increase sensitivity and early identification in tissue.