[Are accessory breasts a potential cause of diagnostic mistakes? Discussion based on case report].

The patient was admitted to the oncology clinic due to the presence of a 3 x 4 cm large tumor in the right axillary region. As the lesion resembled a lipoma, it was surgically excised under general anaesthesia. Histopathologic examination described only physiological breast adenomatous tissue. Accessory breasts usually occur along the 'milk line' which develops in the 6th week of intrauterine life and it extends on the anterior aspect of the body, from the axillary fossa to the groin. Accessory breasts achieve different sizes. They are relatively common in human population (2-6%). In most cases accessory breasts are asymptomatic and cause nothing more than a visible distention which may resemble a tumor. Surgical excision is the treatment of choice due to the risk of development of the same pathological changes as in the normal breast. Histopathologic examination is ubiquitous to ascertain the definite diagnosis.