(Português) Os autores apresentam os aspectos embriológicos, etiopatogênicos e o tratamento cirúrgico das mamas extranumerárias. Analisam 11 ( onze ) casos de anomalia, tratados pelo autor sênior, classificando-os de acordo com o tecido mamário ectópico encontrado. A cirurgia é sempre indicada pelo risco de malignização. Alguns aspectos da técnica operatória são apresentados.


The authors present the embryologic, etiopathogenic aspects and the surgical treatment of the extranumerary breasts. They analyse 11 cases of the anomaly treated by the senior author, classifyng them according to the ectopic mammary tissue found.

Surgery is always indicated Jue to the risk of malignancy. Some aspects of the surgical technique are presented.



Extranumerary breasts are of importance in the mammary patology, not only due to the possibility of suffering malignant transformation but also due to the discomfort and ungraceful aspect that they confer to the patients, caused by the presence of masses at the axillary region, most frequent localization of this pathology.




In a 7 week-old embryo, we observe a thickening of the epidermis, forming a line that extends on each side of the body , from the axilla to the groin, called mammary line. Williams, in his classical diagram, represents on this line 7 pairs of primitive glands, situated 3 proximally and 3 distal from the normal nipple (Fig.1).


With the development of the embryo, only 1 pair remains on the medial regio,. The non-involution of the primitive glands originate accessory breasts. Darwin tried to explain the accessory breasts by means of the atavism theory, that if in one instance it justifies the extranumerary breasts along the mammary line ( even the ones localized in the vulva ), on the other its does not explain the other localizations , such as Schulte, suggest  that originally there may have been a dorsal emplacement of the mammary ridges, progressing at a lather stage towards the ventral surface. Burger and Marcuse believe that accessory mammary glands, such as the ones situated on the buttocks, head , neck and vulva, could be modified sudoriporus glands.




Most authors admit a frequency of 1/500 births; De Cholnoky admits an incidence of 1 to 2% in the caucasian population; the yellow race incidence seems to rise to 5%.

The study of 11 cases, examined and treated by the senior author, of extranumerary breasts allowed us, according to the nature and development of the ectopic mammary tissue, to classify them as:


1 – Polytelia – increase on the number of nipples

2 – Abnormal mammary tissue – gland present, without nipple and/or areola.

3 – Polymastia – accessory breast, complete with nipple, areola and gland.


In this classification, the incidence of the cases studied was the following:


Right Left Bilateral Total
Abnormal breast

Extranumerary nipple

Extranumerary breast













6 4 1 11

 The most frequent localization (Fig. 2) of abnormal breasts was the axillary one. 



The discomfort on the axillary region, augmentation of volume during the menstrual cycles and pain, were the main complaints of the beares of abmormal breast, being that two of the patients only noticed the anomaly when lactation began.   In another, intercurrence of mastitis and abcess motivated the consultation. It should be kept in mind that as glandular tissue in present, the breast is subject to any pathology inhernt to the normal mammary tissue, such as adenofibromas, cysts and malignant degeneration.



1 – In abnormal breasts and polymastias, after exposure of the operating field, the abducted upper limb draws the mass away from the normal breasts , helping placement of the skin incision externally, along a natural fold ( Fig 3 ), the ectopic glandular tissue is undermined and resected. The skin excess is trimmed after delimitation with a small Pitanguy flap dermacator. Closure in two layers; Penrose’s drain, that’s removed after 24 hours. Compressive Dressing.

2 – In polytelias – a fusiform incision is made folow – ig the lines of less tension


Fig. 1-  Mammary  ridge  formed  by thickening  of the  epidermis , aligned   from axilla to pubis.


Fig. 2–  The axillary  localization is the most  frequent for abnormal  breasts.


Fig.3 – Incision over the mass along a natural fold.


Figs. 4, 5 – Polymastia: complete left accessory breast.


Figs 6, 7 –  Ectopic breast localized on the left axilla.


fig. 8 – Transoperatoy  resection of  the ectopic  mammary tissue .


Figs. 9,10 – Preoperative, Abnormal axillary right breast.


Figs. 11,12,13 –  Postoperative. Same  patient after resection of the ectopic tissue. Extranumerary Breast.




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