Radiologic Appearance of Nonpalpable Intramammary Lymph Nodes

Sixty-four well circumscribed nonpalpable lesions, mammographically evaluated as benign and cytomorphologically verified as lymph nodes, were studied concerning mammographic appearance, size and location within the breast. The great majority, 72%, were situated within the upper-outer quadrant, but lymph nodes were also diagnosed in other areas of the breast. Of the verified lymph nodes 50 (78%) had a lower density at the center than at the periphery. These were the only well circumscribed nodules with a low density center observed in a total of 3 623 nonpalpable lesions stereotaxically needled during the same period. Three of the lymph nodes were verified histopathologically. Till now, none of the other 61 lesions has turned out to be a malignant tumor during a follow-up time from 9 to 15 years. Thus a lesion presenting roentgenologically as a well circumscribed nodule with a central area of decreased density compared to the peripheral part can be confidentially diagnosed as a lymph node by the mammograms alone and no further investigation is indicated.