Specific Infections

Specific Infections


Actinomycotic infection of the breast typically presents as an abscess beneath or near the nipple and areola. Sinus tracts usually develop following incision and drainage when the specific diagnosis is unsuspected clinically or with progression of the untreated lesion. A chronic abscess may form, creating a hard mass that simulates carcinoma. Axillary nodal enlargement typically reflects reaction to the inflammatory process more often than spread of actinomycosis to the lymph nodes, but actinomycotic axillary lymphadenitis has been reported (1). In advanced cases, the infection can spread to the chest wall. Extension of pulmonary actinomycosis to the breast has also been described (2). The diagnosis of mammary actinomycosis is made by demonstrating the gram-positive organism as filaments or colonies (sulphur granules). Treatment with penicillin has reportedly been effective (1), but recurrent or advanced infections may require mastectomy.

Infection with Histoplasma capsulatum is endemic in some regions of the United States and other nations. Calcified granulomas have not been described in the breast, but there have been rare instances of localized mammary Histoplasma infection presenting as a solitary unilateral mass, which suggested a neoplasm clinically (3). Histologically, the lesions consist of confluent necrotizing granulomas in which H. capsulatum is demonstrated by a methenamine-silver reaction. The granulomatous reaction is histologically similar to that of nonspecific granulomatous lobular mastitis (4).

Rare instances of other fungal infections of the breast have been reported. These include Cryptococcus (5), Aspergillus (6) and coccidioidomycosis (7), blastomycosis (8), and Nocardia asteroides (9).


Mammary filariasis, caused most frequently by Wuchereria bancrofti, has been reported from tropical and semitropical regions in South America, China, and the Indian subcontinent where infection with this organism is endemic. Involvement of the breast occurs in the chronic phase of infection.

The patient usually presents with a solitary, nontender, painless unilateral breast mass. Multiple lesions occur in a minority of cases. Many of the lesions involve subcutaneous tissue, and they may be fixed to the skin. The resultant hard mass with cutaneous attachment, sometimes accompanied by inflammatory changes, including edema of the skin, appears to be clinically indistinguishable from carcinoma (10). In this setting, axillary nodal enlargement caused by filarial lymphadenitis further complicates the differential diagnosis. Viable microfilaria can be detected in the breast by ultrasound examination if they produce a distinctive pattern of movement referred to as the “filaria dance sign” (11). Mammographically detected calcifications attributed to W. bancrofti and Loa loa infection have been described as having a spiral or serpiginous configuration (12). Microscopic examination typically reveals adult filarial worms that may be well preserved or in varying stages of degeneration (Fig. 3.1). Granulomatous reaction with eosinophilia is present in the surrounding tissue. Fully degenerated worms are likely to become calcified. Adult worms and microfilaria may also be found in axillary lymph nodes (13).

Several examples of mammary cysticercosis, an infection caused by the larvae of tapeworms, have been described. Most instances of mammary cysticercosis were caused by Taenia solium (14). The breast can also be the site of hydatid cyst formation caused by Echinococcus granulosus. The lesion typically presents as a firm, discrete mobile mass. Mammography reveals a dense well-circumscribed tumor within which internal ring structures representing air fluid levels may be seen in an over-penetrated view. Air fluid levels and multiple cysts are seen to better advantage by ultrasound (15). Mammary hydatid disease can be recognized by finding fragments of the adult worm, the hydatid membranes and hooklets in a biopsy, or in the aspirated cyst contents (16) (Fig. 3.2A). Needle core biopsy sampling of mammary sparganosis due to the tapeworm spirometra has been described (17

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Jun 18, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Specific Infections

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