Primary breast tuberculosis in an HIV-infected patient

Case report

A 26-year-old woman presented to the department of infectious diseases with a 5-month history of a left-sided breast lump associated with pain; the pain worsened after exercise, and swelling progressed slowly. She was unmarried and had no history of breastfeeding. She had no past history of tuberculosis, night sweats, fever, or weight loss. Physical examination demonstrated that the patient was in good general condition; examination of the inner lower quadrant of the left breast gland revealed a sinus with purulent discharge visible (Figure1(a)), measuring about 20 mm by 30 mm, local skin temperature was normal, and no swollen axillary lymph nodes were found. Before her admission, she had received cefuroxime sodium for 14 days, but the condition did not improve.

Results from laboratory tests were as follows: human immunodeficiency virus (HIV)-1 antibody was positive, HIV viral load was 10,100 copies/mL, CD4⁺T cells were 362 cells/mm³, liver function and kidney function were normal, whole blood count was normal, erythrocyte sedimentation rate was 9 mm/1 h (reference range, 0–20), and procalcitonin was 0.082 ng/mL (reference range, 0–0.5). Ultrasound scan showed a dark area on the left breast with small dense light spots, measuring about 35 mm by 21 mm; color Doppler flow imaging showed no blood flow signal, and an abscess was considered (Figure1(b)). The computed tomography (CT) image showed two circular nodular shadows in the inner lower quadrant of the left breast (Figure1(c)), the larger lesion was about 26 mm by 19 mm (border was unclear), the center CT value of the uneven density was about 35 Hounsfield units (HU), the marginal CT value was about 50 HU, and hence, infectious disease was considered. CT images of lungs and bronchopulmonary tree were normal (Figure 1(d)). Biopsy of the breast lump for histological examination suggested granulomatous inflammation.

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Figure1. (a) Examination of the inner lower quadrant of the left breast gland revealed a sinus with purulent discharge visible. (b) Ultrasound scan of breast abscess. (c) CT image showing two circular nodular shadows in the inner lower quadrant of the left breast. (d) CT image of normal lungs.

The above tests did not determine the pathogen, so secretions from the sinus were submitted for bacterial culture and GeneXpert for Mycobacterium tuberculosis/Rifampicin resistance (Xpert MTB/RIF, Cepheid, Sunnyvale, California) examination. Bacterial culture was negative (two times), Ziehl-Neelsen staining for acid-fast bacilli was negative, Xpert MTB/RIF was positive, and rifampicin resistance was not detected. No evidence of tuberculosis was found in other organs; these findings supported the diagnosis of primary breast tuberculosis and acquired immunodeficiency syndrome (AIDS). The patient was given lamivudine, tenofovir, and efavirenz for antiretroviral therapy. She was treated with incision, drainage, and dressing, not with mastectomy. The anti-tuberculosis treatment regimen was rifampicin (R), isoniazid (H), pyrazinamide (Z), and ethambutol (E) for 2 months and then HR for 4 months. After the medication, she did not have any ongoing symptoms. At a 6-month follow-up, her breast sinus had healed, and her CD4⁺ count was 461 cells/mm³.

Discussion

In people living with HIV (PLHIV), the presentation of tuberculosis can be nonspecific and atypical, especially in the extrapulmonary forms. ¹ Breast tuberculosis, whether primary or secondary, is a rare disease of difficult diagnosis. ² In this case, the patient had no typical clinical manifestations of tuberculosis and was eventually diagnosed by Xpert MTB/RIF; therefore, it is important to remember that breast tuberculosis is still present and should be suspected particularly in PLHIV.^3,4

Differential diagnosis most often involves carcinoma of the breast but may include benign neoplasms, pyogenic abscess, fungal infection, actinomycosis, fat necrosis, and sarcoidosis. ⁵ Imaging examination of the breast may not distinguish between benign and malignant lesions, so biopsy of the pathological tissue is strongly recommended. ⁶

Anti-tubercular chemotherapy remains the cornerstone for the treatment of breast tuberculosis. ⁷ This includes 2 months of intensive therapy with four drugs (HRZE), which is then followed by a continuation phase of 4 months with two drugs (HR). At some centers, 9-month therapy is given (includes 7 months of continuation phase), with no or little clinical benefit. ⁸ In addition, for PLHIV, attention should be paid to the drug-drug interactions between anti-tuberculosis drugs and antiretroviral therapy drugs. If medical treatment fails, partial excision or simple mastectomy may be needed. For patients who are not likely to comply with a complicated therapeutic regimen, a surgical approach at the outset may be appropriate. ⁵

This case showed that we cannot rely solely upon imaging to confirm the presence of breast tuberculosis, especially among PLHIV; clinical examination, imaging, appropriate diagnostic biopsies, and Mycobacterium tuberculosis-related tests should all be combined so as to avoid misdiagnosis.