Background
Brucellosis is one of the most common zoonotic diseases worldwide, especially in Asia and Middle Eastern countries such as Iran [1,2,3], which is transmitted to humans through the consumption of unpasteurized dairy products and direct contact with infected animal tissues [4,5,6]. It has been demonstrated that brucellosis can involve any part of the body including the musculoskeletal system, genital organs, gastrointestinal system, nervous system, respiratory system, circulatory system, skin, heart, liver, spleen, bone, kidney, brain, epididymis, ovary, and gallbladder [7,8,9] and it causes a systemic infection from asymptomatic disease to fatal illness [10,11] and it can mimic other infectious and non-infectious diseases [4,12]. So it is known as a “great imitator” [10].
The onset of the disease can be insidious and when specific organ involvement is detected it is defined as focal brucellosis [2,10,11]. In addition, arthritis, spondylitis, endocarditis, meningitis, orchitis due to brucellosis are not uncommon [10,11,13]; but cutaneous and subcutaneous involvement with brucellosis are uncommon [14]. Although soft tissue locations are usually related to a penetrating injury, the hematogenous spread is considered an important pathologic route [8,13,15].
Although breast infection with granulomatous mastitis is described in animals, infection of mammary glands with brucella is extremely rare in human brucellosis [13,14,15]. Brucella-infected mammary glands have been reported in a few cases and it is often hematogenous such as a metastatic abscess in endocarditis [11]. In one case I. Gasser et al. reported the isolation of Brucella melitensis from a suspected breast tumor of a woman who also had uveitis [13].
Osteoarticular lesions which are the most common complications in brucellosis include peripheral arthritis, osteomyelitis, spondylitis, sacroiliitis, and bursitis. Common joints consist of the knee, hip, ankle, and sacroiliac and less frequent ones include the shoulder, sternoclavicular, and temporomandibular [10,11,16,17].