Intramammary lymph nodes: a question seeking for an answer or an answer seeking for a question?

Intramammary lymph nodes have not received for a long time enough attention from the medical literature and thus many of their characteristics are not sufficiently explored. Their incidence at various studies ranges between 0, 7 and 48%. They may be found in all breast quadrants but usually at the Upper Outer Quadrant (UOQ). Their radiological image at mammography is that of a well circumscribed density with an area of lower density at centre representing the hilum and at ultrasonography of a hypoechoic, circumscribed mass with an echogenic hilum. Their role in lymphatic drainage of breast regions is important although it is not known if they represent true sentinel nodes or if lymphatic drainage to them comes from ectopic, independently developed pathways. Intramammary Lymph Nodes are involved in a variety of clinical situations including benign situations, tumor metastasis, breast lymphoma and breast cancer. Their importance over breast cancer is not fully defined but there is evidence that they worsen prognosis and they may change therapeutic decisions. Breast cancer and Breast lymphoma can coexist and interfere.