Clinical Profile:

A 56-year-old woman came with complaints of painless lump in the right breast since three months. She had experienced easy fatigability, drooping of eyelids and breathlessness on exertion since one year and had been  diagnosed with myasthenia gravis and was started on immunosuppressants five months ago. She had no history of TB or TB contact. On examination, a solitary, firm and non-tender lump in the lower inner quadrant of the right breast was palpable. There were no skin changes or discharging sinuses.

Radiological findings:

HRCT thorax  (Fig. 1) A well-defined soft tissue density was seen in the anterior aspect of superior mediastinum. CT guided biopsy revealed polygonal epithelial cells with interspersed lymphocytes suggestive of Thymoma type B1. (Only plain scan done as iodinated contrast is contraindicated in myasthenia gravis). 

An elliptical,  pleura- based,  hyperdense lesion with peripheral calcification and central fluid density was seen along the lateral aspect of right hemithorax suggestive of empyema.

There was lso a lobulated soft tissue density lesion in the lower inner quadrant of the right breast extending into the underlying pectoral muscle. Correlation with an ultrasonogram was recommended.

Figure 1A :  A well defined soft tissue density was seen in the anterior aspect of superior mediastinum consistent with a thymoma.

 Fig 1 B and 1 C - An elliptical pleural based hyperdense lesion with peripheral calcification and central fluid density is seen along the lateral aspect of right hemithorax suggestive of an empyema.

Fig 1D and 1 E : A lobulated soft tissue density lesion is seen in the inner lower quadrant of the right breast extending into the underlying pectoral muscle.

Fig 2  A and 2 B :  An irregular heterogeneously hypoechoic tubular lesion with posterior enhancement, lying parallel to the breast parenchyma was seen in the right breast at 3 o’clock to 5 o’clock position, at a distance of 2 cm from the nipple areola complex. There was no vascularity in the lesion. There were no calcifications in the lesion. The lesion was extending into the underlying pectoralis muscle. (BIRADS 4A)

Ultrasonogram of the right breast (Fig. 2) showed an irregular,  heterogeneously hypoechoic,  tubular lesion with posterior enhancement, lying parallel to the breast parenchyma at the 3 o’clock to 5 o’clock position, at a distance of 2 cm from the nipple areola complex. There was no vascularity in the lesion. There were no calcifications. The lesion extended into the underlying pectoralis muscle. (BIRADS 4A)

The lesion was soft on elastography (Fig. 3) . FNAC was advised.

Fig 4 The FNAC of the right breast lesion revealed necrotizing granulomatous inflammation (Epithelioid histiocytes forming granulomas (Fig 4A) and areas of necrosis  (Fig 4B)) suggestive of mycobacterial etiology.

Discussion

Mammary tuberculosis is a rare clinical entity, often mimicking breast cancer or abscesses of benign or malignant origin. Tuberculous mastitis is usually unilateral and should be considered in a state of immunodeficiency  (1).

Lactating women are at a higher risk, probably due to the increased blood supply to the breasts and to dilatate ducts, making them more vulnerable to lacerations and infection (2)

The routes of spread to the breast are hematogenous, lymphatic, direct extension from the thoracic wall or the axillary lymph nodes, or inoculation through traumatized skin or ducts (3,4,5)

The commonest clinical presentation is that of a lump, most often located in the central or upper outer quadrant of the breast. The lump can mimic breast carcinoma, being hard, with irregular border, fixed to either the skin or the muscle or even to the chest wall (5,6).  The lump may be followed by inflammation and abscess formation, skin ulceration and diffuse mastitis.

Based on radiological and clinical characteristics the disease can be described by three forms: nodular, diffuse and sclerosing.

The nodular form is well circumscribed, slow growing, with an oval tumour shadow on mammography, mimicking breast cancer. The disseminated form is characterized by multiple lesions associated with sinus formation. This form mimics inflammatory breast cancer on mammography. The sclerosing form of the disease is seen in elderly women and is characterized by an excessive fibrotic process (2,7,8).

The diagnosis of mammary tuberculosis can be made by ultrasonography, mammography.

On ultrasonography, a hypoechoic mass may be found in 60% of patients and a fistula or a sinus tract may be identified (3,6).

Mammography is not useful, especially in young women, due to high density of the breast tissue. Mammography findings in elderly women are generally indistinguishable from breast carcinoma.

Computed tomography and nuclear magnetic resonance are used to evaluate the extension of the lesion beyond the breast.

The gold standard for the diagnosis of breast tuberculosis remains detection of M.Tuberculosis by Ziehl Nielsen staining or by culture. 

Fine needle aspiration cytology may not be able to detect the responsible pathogen itself, but detecting the presence of epithelioid cell granulomas and necrosis, leads to definitive diagnosis in a majority of the cases.

The differential diagnosis include breast carcinoma and other diseases such as fatty necrosis, plasma cell mastitis, periareolar abscess, idiopathic granulomatous mastitis and infections like actinomycosis and blastomycosis (3,9,10,11,12).

Anti-tubercular therapy with four drugs is the primary line of treatment. Surgical intervention in the form of an excisional biopsy is necessary mainly for diagnostic purposes and is required for drainage of breast abscesses, excision of residual sinus tracts or lumps after poor response to anti-tuberculosis therapy. Simple mastectomy, most often without axillary lymph node dissection, is reserved for cases with extensive disease ( 7,8,10,13 )

Conclusion:

Considering the co-existence of Myasthenia gravis with extrathymic malignancies, and an increased risk of second malignancy in patients with thymoma, a painless and slow growing breast lump in such patients could be suspicious of a breast malignancy. The possibility of tuberculous mastitis, although rare, should be considered in such cases, taking into account the immunosuppressant therapy received by these patients which predisposes them to the  development of pulmonary or extrapulmonary tuberculosis.

Early diagnosis and initiation of Anti-tubercular therapy in patients with tuberculous mastitis helps in prompt clinical recovery.

References

1) Mirsaeidi S.M., Masjedi M.R., Mansouri S.D., Velayati A.A. Tuberculosis of the breast: report of 4 clinical cases and literature review. East Mediterranean Health Journal. 2007;13:670–676. [PubMed] [Google Scholar]

2) Maroulis I., Spyropoulos C., Zolota V., Tzorakoleftherakis E. Mammary tuberculosis mimicking breast cancer: a case report. Journal of Medicine Case Reports. 2008;2:34. [PMC free article] [PubMed] [Google Scholar]

3) da Silva B.B., Lopes-Costa P.V., Pires C.G., Pereira-Filho J.D., dos Santos A.R. Tuberculosis of the breast: analysis of 20 cases and a literature review. Transactions of the Royal Society of Tropical Medicine and Hygiene. 2009;103:559–563. [PubMed] [Google Scholar]

4) Fadaei-Araghi M., Geranpayeh L., Irani S., Matloob R., Kuraki S. Breast tuberculosis: report of eight cases. Archives of Iranian Medicine. 2008;11:463–465. [PubMed] [Google Scholar]

5) Jah A., Mulla R., Lawrence F.D., Pittam M., Ravichandran D. Tuberculosis of the breast: experience of a UK breast clinic serving an ethnically diverse population. Annals of the Royal College of Surgeons of England. 2004;86:416–419. [PMC free article] [PubMed] [Google Scholar]

6) Teo T.H., Ho G.H., Chaturverdi A., Khoo B.K. Tuberculosis of the chest wall: unusual presentation as a breast lump. Singapore Medical Journal. 2009;50:e97–e99. [PubMed] [Google Scholar]

7) Madhusudhan K.S., Gamanagatti S. Primary breast tuberculosis masquerading as carcinoma. Singapore Medical Journal. 2008;49:e3–e5. [PubMed] [Google Scholar]

8). Tewari M., Shukla H.S. Breast tuberculosis: diagnosis, clinical features and management. Indian Journal of Medical Research. 2005;122:103–110. [PubMed] [Google Scholar]

9) Luh S.P., Chang K.J., Cheng J.H., Hsu J.D., Huang C.S. Surgical treatment for primary mammary tuberculosis – report of three octogenarian cases and review of literature. Breast Journal. 2008;14:311–312. [PubMed] [Google Scholar]

10). Akcay M.N., Saglam L., Polat P., Erdogan F., Albayrak Y., Povoski S.P. Mammary tuberculosis – importance of recognition and differentiation from that of a breast malignancy: report of three cases and review of the literature. World Journal of Surgery and Oncology. 2007;5:67. [PMC free article] [PubMed] [Google Scholar]

11). da Silva B.B., Dos Santos L.G., Costa P.V., Pires C.G., Borges A.S. Primary tuberculosis of the breast mimicking carcinoma. American Journal of Tropical Medicine and Hygiene. 2005;73:975–976. [PubMed] [Google Scholar]

12). del Agua C., Felipo F., Paricio J., Equizabal C., Delgado M. Tuberculosis of the breast as a pseudotumoral image. Breast Journal. 2006;12:180. [PubMed] [Google Scholar]

13). Sriram K., Moffatt D., Stapledon R. Tuberculosis infection of the breast mistaken for granulomatous mastitis: a case report. Cases Journal. 2008;1:273. [PMC free article] [PubMed] [Google Scholar] [Ref list]

Acknowledgement :

We are grateful to the Department of Pathology at our institution for providing  an image of the histopathology of the biopsy specimen and the description of the findings,