|ECR 2015 / C-1031|
|Pathological findings of suspicious axilary lymph nodes in patients with normal screening mammograms|
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Histopathology and/or cytology of these 57 lymph nodes showed 11 malignant and 46 benign results. Of the malignant results, 6 were non-Hodgkin lymphomas and 5 were metastases from breast carcinoma. Of the 46 cases with a benign results, 2 were granulomatous lymphadenitis (one tuberculosis), 2 showed patterns of sinus histiocytosis ( Fig. 1 ), 1 was a siliconoma and the other 41 benign results showed benign reactive lymph node hyperplasia ( Table 1 ).
The largest category (71.9%) seen was nonspecific benign reactive lymphadenopathy; this category included all of the clinically or pathologically benign cases in which no causative agent could be identified. It is caused by inflammation of the lymph nodes or the adjacent organs, such as the breast or lung. Collagen vascular disorders, also cause nodal hyperplasia. On mammography, nodal hyperplasia shows increased density that cannot be distinguished from lymphoma or metastatic lymphadenopathy ( Fig. 2 ).
Tuberculous lymphadenitis is a common cause of benign peripheral lymphadenopathy, especially in our environment with a prevalence between 15-20 % of the population of Cantabria affected by tuberculosis. Typically, the presence of enlarged, mammographically dense, and sonographically hypoechoic axillary nodes containing coarse internal calcifications suggests the diagnosis. Tuberculous lymphadenitis commonly has ragged indistinct borders because of periadenitis and surrounding soft tissue edema ( Fig. 3 Fig. 4 ).
The siliconoma represents an inflammatory mass caused by foreign body reaction to silicone gel. We usually find it at the edge of the implant or in the axilla but it can occur wherever silicone migrates (lymph nodes, arm, abdominal wall, back, groin, etc).
Mammographic findings consist on a dense, circumscribed round mass with or without rim calcifications and sonographically it sometimes presents as “snowstorm" (mass of echogenic noise on US due to acoustic scattering with distal margin not visible) ( Fig. 5 ).
Non-Hodgkin lymphomas and metastatic breast cancer were the second and third most frequent causes for lymphadenopathy, 10.5% and 8.8% respectively.
On mammography, lymphoma shows well-defined, markedly enlarged, and homogeneously hyperdense lymph nodes ( Fig. 6 ). On ultrasound, we can see both, markedly hypoechoic/pseudocystic appearance of the nodes and a heterogeneous micronodular pattern. Lymphomatous nodes are likely to show mixed vascularity (peripheral and hilar) ( Fig. 7 ).
Metastatic lymphadenopathy is nonspecific at imaging, especially when
the metastases is early and small. Although malignant lymph nodes usually have circumscribed borders on mammography, ill-defined or spiculated borders may be seen in cases with extranodal spread. Rarely, tumoral calcifications can be identified within metastatic lymph nodes. On ultrasound, metastatic nodes are characterized by a more spherical shape and more frequent hilar loss and necrotic center than lymphoma or tuberculous lymphadenitis. Metastatic nodes tend to have peripheral or mixed (both peripheral and hilar) vascularity on Doppler ultrasound ( Fig. 8 Fig. 9 ).