BILATERAL TUBERCULAR MASTITIS

Abstract

Breast tuberculosis is a rare form of tuberculosis. Moreover the disease is often overlooked and misdiagnosed as carcinoma or pyogenic abscess. Reports on breast tuberculosis from India have been few; reported incidence of breast tuberculosis amongst the total number of mammary conditions varies between 0.64 and 3.59 per cent. Bilateral involvement is still more uncommon (3%). Most accepted view for spread of infection is centripetal lymphatic spread as axillary node involvement was shown to occur in 50 to 75 per cent of cases of tubercular mastitis. Here we re-port a case of a young female who presented with draining sinuses in the breast and no axillary lymphadenopathy. Fine needle aspiration cytology (FNAC) of breast lump showed evidence of granulomatous mastitis. She was given therapeutic trial of four drug antitubercular treatment. Both the lump disappeared and sinus healed after six months of antitubercular treatment. Thus a retrospective diagnosis of tu-bercular mastitis was made.

INTRODUCTION

Breast tuberculosis is a rare form of tuberculosis¹. It is rare in the western countries, incidence being less than 0.1 per cent of breast lesions examined Histologically²³. But, with the global spread of AIDS, mammary tuberculosis may no longer be uncommon in the developed world (as an AIDS defining condition)¹⁴. The incidence of tuberculosis, in general, is still quite high in India and so is expected of the breast tuberculosis. But the disease is often overlooked and misdiagnosed as carcinoma or pyogenic abscess⁵. Thus, reports on breast tuberculosis from India have been few. Several Indian series reported the incidence of breast tuberculosis amongst the total number of mammary conditions to vary between 0.64 and 3.59 per cent⁶. In another series, tuberculosis a relatively rare lesion in the breast, was observed in 18 patients (seventeen of whom were of child bearing age) with an incidence of 1.02%⁷.

The breast may become infected in a variety of ways⁸ e.g., (i) haematogenous, (ii) lymphatic, (iii) spread from contiguous structures, (iv) direct inoculation, and (v) ductal infection. Of these, the most accepted view for spread of infection is centripetal lymphatic spread⁶. The path of spread of the disease from lungs to breast tissue was traced via tracheobronchial, paratracheal, mediastinal lymph trunk and internal mammary nodes¹⁶. According to the Cooper's theory, communication between the axillary glands and the breast results in secondary involvement of the breast by retrograde lymphatic extension⁸. Supporting this hypothesis was the fact that axillary node involvement was shown to occur in 50 to 75 per cent of cases of tubercular mastitis⁹. Breast is resistant to tuberculous infection by blood stream, even in debilitated patients of tuberculosis¹⁰. Occasionally, direct extension from contiguous structures such as infected rib, costochondral cartilage, sternum, shoulder joint and even through the chest wall from a tuberculous pleurisy or via abrasions in the skin can occur¹¹. Coincidental tuberculosis of the faucial tonsils of suckling infants has been suggested as one of the common routes of spread of breast tuberculosis from the suckling infant to the nipple, and in turn, to the lactating breast via lacticiferous ducts¹². In all cases, bacilli infected the ducts and spared the lobules. This may be the sole example of primary breast tuberculosis relevant even today.

CASE SUMMARY

A 29 year old female presented to our department of pulmonary medicine, KGMU, Lucknow with complaint of bilateral painless breast lump for 3 months associated with fever which was low grade and not associated with chills or rigor. It was followed by discharge from the both lumps one month later. The patient had no complaint of cough or breathlessness. The patient was not breastfeeding. There was no peripheral lymphadenopathy or clubbing. There was a 2 cm sized spherical lump in the upper inner quadrant of the breast on right and lower inner on left side. Discharging sinus was present on both sides. The lumps were fixed to skin, had a smooth surface, were non tender and had no associated peau d′ orange appearance. Her respiratory system was within normal limits on examination. The counts and Chest X-ray were within normal limits. She was given adequate trial of antibiotics without any response. The FNAC of breast lump showed evidence of granulomatous mastitis. Her mantoux test showed an induration of 12 mm. On the basis of her clinical presentation mantoux test and FNAC report she was given therapeutic trial of four drug (rifampicin, isoniazid, pyrazinamide and ethambutol) antitubercular treatment. Both the lump disappeared and sinus healed after six months of institution of antitubercular treatment. Thus a retrospective diagnosis of tubercular mastitis was made.

DISCUSSION

The history of the presenting symptoms in breast tuberculosis is usually less than a year but varies from few months to several years¹³¹⁴. Breast tuberculosis commonly affects women in their reproductive age group¹⁹, between 21-30 yr, similar to the highest incidence of pulmonary tuberculosis reported in the same age group of females¹⁴.This may be because the female breast undergoes frequent changes during the period of activity and is more liable to trauma and infection¹³. In pregnant and lactating women, the breast is vascular with dilated ducts, predisposed to trauma making it more susceptible to tubercular infection¹⁵¹⁶. It is uncommon in prepubescent females and elderly women¹⁷. Bilateral involvement is uncommon (3%)¹⁵. Breast tuberculosis most commonly presents as a lump¹²¹⁸ in the central or upper outer quadrant of the breast²⁰. In our patient the lumps were present in the upper inner quadrant on right and lower inner quadrant on left. Tubercular mastitis is probably due to frequent extension of tuberculosis from axillary nodes to the breast. But the lump is usually painful. Breast remains mobile unless involvement is secondary to tuberculosis of the underlying chest wall¹⁵. Tubercular ulcer over the breast skin and tubercular breast abscess with or without discharging sinuses are other common forms of clinical presentation of breast tuberculosis¹⁴. Peau d′ orange is often seen in patients with extensive axillary nodal tuberculosis. Purulent nipple discharge or persistent discharging sinus may be the rare presenting feature. Our patient presented with bilateral draining sinuses. Breast tuberculosis was first classified into five different types by Mckeown and Wilkinson¹⁶: (i) Nodular tubercular mastitis, (ii) Disseminated or confluent tubercular mastitis, (iii) Sclerosing tubercular mastitis, (iv) Tuberculous mastitis obliterans, and (v) Acute miliary tubercular mastitis. There are hardly enough reports in the past two decades to merit the sclerosing tubercular mastitis, tuberculous mastitis obliterans and acute miliary tubercular mastitis in the classification of breast tuberculosis. Thus at present, breast tuberculosis may be reclassified as nodular, disseminated and abscess varieties. The sclerosing type, mastitis obliterans and miliary variety are of historical importance only. Our patient belonged to the abscess variety.

DIAGNOSIS

Diagnosis warrants a high index of suspicion on clinical examination and pathological or microbiological confirmation of all suspected lesions. Mantoux test is usually positive in adults in endemic area for tuberculosis and is of not great help for diagnosis of breast tuberculosis. The modern radiological investigations help in defining the extent of the lesion rather than in diagnosis. Sophisticated radiological tools like mammography, computed tomography (CT-scan) and magnetic resonance imaging (MRI) of the breast have been extensively explored for the diagnosis of breast tuberculosis but of no avail.

Fine needle aspiration cytology (FNAC) from the breast lesion continues to remain an important diagnostic tool of breast tuberculosis¹. Approximately 73per cent cases of breast tuberculosis can be diagnosed on FNAC when both epitheloid cell granulomas and necrosis are present¹. Failure to demonstrate necrosis on FNAC does not exclude tuberculosis in view of small quantity of the sample harvested and examined. The demonstration of acid-fast bacilli (AFB) on FNAC is not mandatory, since for AFB to be seen microscopically, their number must be 10,000- 100,000/ml of material. AFB negative breast abscess that fail to heal despite adequate drainage and antibiotic therapy, and those with persistent discharging sinuses should raise suspicion of underlying tuberculosis. In our case patient was given adequate trial of antibiotics without any response. In a country like India, the diagnosis of Idiopathic granulomatous mastitis must be made with caution, even in the absence of AFB. Only after a sufficient trial of antituberculosis treatment has been given and the patient fails to respond should an alternative diagnosis be suggested²¹.

Though mycobacterial culture remains the gold standard for diagnosis of tuberculosis, the time required and frequent negative results in paucibacillary specimens are important limitations. Moreover, culture is not always helpful in the diagnosis of breast tuberculosis¹⁸. In our case also culture gets contaminated. Histological findings include epitheloid cell granulomas with caseous necrosis in the specimen. Core needle biopsy yields a good sample often yielding a positive diagnosis. However, open biopsy (incision or excision) of breast lump, ulcer, sinus or from the wall of a suspected tubercular breast abscess cavity almost always confirms breast tuberculosis¹¹⁶. Histologically, tubercular mastitis is a form of granulomatous inflammation. In this patient also biopsy was suggested but patient and her attendants refused for the procedure.

Polymerage Chain Reaction in the diagnosis of breast tuberculosis is less often reported, mostly as a tool to distinguish tubercular mastitis from other forms of granulomatous mastitis in selected reports²². However, PCR is by no means absolute in diagnosing tubercular infection and false negative reports are still a possibility²³.

TREATMENT

The treatment of breast tuberculosis consists of anti-tubercular chemotherapy (ATT) and surgery with specific indications. ATT is the backbone of treatment of breast tuberculosis²⁴. This patient also responded very well to antitubercular treatment. Rather due to effective response to antitubercular treatment retrospectively the diagnosis of tubercular mastitis could be made. The overall prognosis is good with adequate medical treatment¹⁵. However, minimal surgical intervention is required for drainage of breast abscess or biopsy from the abscess wall, scraping of sinuses in the breast, incisional or excisional biopsy¹⁵¹⁶. However this patient responded very well to ATT thus no surgical intervention was required.

Fig 1: Photograph showing multiple draining sinus in breast

Fig 2: Fine needle aspiration cytology slide showing typical histopathological features of granulomatous mastitis.

Replies to Comments

1. Culture for mycobacterium tuberculosis was sent but report came out to be contaminated.
2. In a country like India, the diagnosis of Idiopathic granulomatous mastitis must be made with caution even in the absence of AFB. Only after a sufficient trial of antituberculosis treatment has been given and the patient fails to respond then only alternative diagnosis should be suggested.
3. Diagnosis part which was lengthy has been cut short.
4. Reference has also been cut short.
5. Full forms of abbreviations have been added.