Sara Jimenez MD, Presenter: Nothing to Disclose

Ana B. Delgado MD, Abstract Co-Author: Nothing to Disclose

Jose Maria Oliver-Goldaracena, Abstract Co-Author: Nothing to Disclose

Silvia Alonso Roca, Abstract Co-Author: Nothing to Disclose

Noemi Camara, Abstract Co-Author: Nothing to Disclose

Diana Exposito MD, Abstract Co-Author: Nothing to Disclose

To assess the value of breast MRI and US in the detection of Internal Mammary Lymph Node (IMLN) metastases in patients with Invasive Breast Carcinoma (IBC).

From January 2007 to January 2010 we performed preoperative US and MRI examinations to 325 patients with IBC. We evaluated the internal mammary region looking for lymph nodes and registering their imaging features (size and morphology). We performed US or CT-guided FNA in IMLN that measured 8 mm or more and follow-up MRI in the lymph nodes considered as benign or considered suspicious with negative FNA cytology. We also studied the site and size of the primary tumor, the presence or absence of accompanying axillary lymph nodes and their characteristics and the existence of distant metastases.

We identified IMLN in 19 of 342 patients (5.5%) on MRI. The mean diameter of the IMLN was 10.8 mm. Of the 19 patients with IMLN on MRI, 12 were considered metastatic (mean diameter 13.8 mm), 9 with positive FNA cytology (7 US-guided and 2 CT-guided), and the 3 others by follow-up MRI studies (disappearance or significant decrease in size after chemotherapy). The other 7 patients with IMLN on MRI were considered negative (mean diameter 5 mm) due to their size, shape and stability in follow-up MRI. US detected IMLN in 10 of the 19 patients that MRI identified (52.6%). Out of these, 8 were part of the considered as metastatic. So, compared to MRI, US detected 2/3 of the metastasic IMLN. Over 75% of the patients with metastatic IMLN showed important and extense axillary involvement (axillary lymph nodes between 20 and 58 mm). The mean size of the IBC in patients with metastatic IMLN was 5.2 cm.Only 1 patient presented distant metastases at diagnosis. In 3 patients the detection of metastatic IMLN modified the treatment protocol, adding the internal mammary chain to the radiotherapy field. 

MRI is useful for detecting metastatic IMLN in patients with IBC, with an incidence of over 5%. In our study US detected 2/3 of the metastatic IMLN identified by MRI. Nearly all metastatic IMLN were larger than 10 mm and most cases were locally advanced breast cancers with extensive axillary involvement.

When performing US and MRI studies, IMLN can be evaluated without substantial increase in examination time. This provides information about metastatic lymph nodes, which is important for treatment.

Jimenez, S, Delgado, A, Oliver-Goldaracena, J, Alonso Roca, S, Camara, N, Exposito, D, Evaluation of Internal Mammary Lymph Node Metastases in Invasive Breast Carcinoma by MRI and US: A Prospective Study.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9007360.html