|Year : 2013 | Volume
| Issue : 1 | Page : 111-113
Reactive intramammary lymph node mimicking recurrence on MRI study in a patient with prior breast conservation therapy
Seema A Kembhavi1, Himanshu Choudhary1, Kedar Deodhar2, Meenakshi H Thakur1
1 Department of Radiodiagnosis, Tata Memorial Centre, Parel, Mumbai, India
2 Department of Pathology, Tata Memorial Centre, Parel, Mumbai, India
|Date of Web Publication||10-Apr-2013|
Seema A Kembhavi
Department of Radiodiagnosis, Tata Memorial Centre, Parel, Mumbai
Source of Support: None, Conflict of Interest: None
Breast conservative therapy (BCT) is a well accepted form of treatment for patients with early stage breast cancer. The incidence of ipsilateral breast tumor recurrence is higher in patients undergoing BCT than in those patients undergoing Modified Radical Mastectomy (MRM) without any adverse effect on survival. Patients treated with BCT are put on active surveillance using clinical breast examination and mammography. The radiologist reading the follow-up mammograms is on high alert and any neo-density is viewed with suspicion. MRI may be used as a problem solving tool. At such a time, an innocuous intra-mammary node can mimic malignancy on MRI. We want to showcase one such typical example with histological proof and highlight that type III curve may be seen in an intramammary node. Our case also reinforces the utility of second look ultrasound which is a faster, cheaper and easier method for localization and biopsy of abnormalities seen on MRI.
Keywords: Breast conservative therapy, Breast MRI, Intra-mammary lymph node, Type III curve
|How to cite this article:|
Kembhavi SA, Choudhary H, Deodhar K, Thakur MH. Reactive intramammary lymph node mimicking recurrence on MRI study in a patient with prior breast conservation therapy. J Can Res Ther 2013;9:111-3
|How to cite this URL:|
Kembhavi SA, Choudhary H, Deodhar K, Thakur MH. Reactive intramammary lymph node mimicking recurrence on MRI study in a patient with prior breast conservation therapy. J Can Res Ther [serial online] 2013 [cited 2020 May 28];9:111-3. Available from: http://www.cancerjournal.net/text.asp?2013/9/1/111/110396
| > Introduction|| |
Breast conservation therapy (BCT) is a well accepted treatment for early stage breast cancer, as the overall survival is comparable to patients treated with mastectomy.  At the same time, the rate of ipsilateral breast tumor recurrence is higher in patients undergoing conservation.  Patients treated with BCT are put on active surveillance, mammography being the most accepted method. Sonography serves as an adjunct and MRI is a problem solving tool or can be used for patients with high risk of recurrence. In a clinical situation where patient has been treated with BCT, the threshold of calling a lesion malignant is high and an innocuous intra-mammary node can mimic malignancy, especially because it can have a type III curve. Our case report with its histological proof exhibits a typical example of such a case. The aim of this report is to highlight a pitfall of type III curve and emphasize on the utility of second look ultrasound.
| > Case Report|| |
In the summer of 2011, a 45 year old female with history of breast conservation therapy, done year and a half ago, for a carcinoma in the upper inner quadrant of the right breast, came for first follow up mammography. The medio-lateral oblique mammogram revealed a tiny 6-7mm sized nodule in the upper aspect of the right breast, superior to the operated site [Figure 1] and just anterior to the pectoralis muscle. This nodule was not appreciable on CC view, probably due to its proximity to the chest wall. On targeted sonography for the post op site was normal. The MRI performed for further evaluation revealed two identical subcentimeter sized nodules (6 × 7mm and 5 × 8mm) in the upper outer quadrant of the breast (one of them shown here in [Figure 2]). These were in fact far away from scar site, unlike what was perceived on mammography. The nodules were hypointense on T1WI, isointense on T2W and hyperintense on STIR images. They had well defined smooth margins and showed homogeneous enhancement. On dynamic MRI, they showed rapid uptake of contrast with early wash out (Type 3 curve). Possibility of these lesions being intrammamary lymph nodes was raised because of their location, smooth margins and type III curve. However, in the given clinical setting, a neoplastic cause could not have been ruled out with certainty, especially because the nodule neither had a typical reniform shape nor a fatty hilum. Knowing the exact location of these nodules, a second-look Ultrasonography (US) was done. The nodules were identified and later marked for excision biopsy. The pathology revealed that the nodules were indeed reactive lymph nodes with mixture of lymphocytes, dendritic cells and histiocytes containing brown pigment [Figure 3].
|Figure 1: The medio-lateral oblique mammogram reveal a tiny subcm sized nodule (arrow) in the upper aspect of the right breast, superior to the operated site (clip seen) and just anterior to the pectoralis muscle. This nodule is not seen on the CC view, probably due to proximity to chest wall|
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|Figure 2: This composite image shows a tiny nodule in the lateral aspect of the breast, close to the chest wall, which appears hypointense on T1 and hyperintense on STIR and shows hyperperfusion on the dynamic scan with type III kinetics|
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|Figure 3: This (H and E, × 400) image of the nodule shows mixture of lymphocytes, dendritic cells and histiocytes containing brown pigment, thus confirming it to be reactive lymph node|
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| > Discussion|| |
MRI breast is a problem solving modality. It aids in better detection and further characterization of breast lesions, as in this case. The morphological and kinetic information, both need to be taken into consideration to reach the most probable diagnosis.
Our patient revealed two tiny nodular lesions having well defined smooth margins and homogeneous enhancement. Both these features are associated with benign lesions.  Malignant lesions more often have spiculated or irregular margins and can show a variety of enhancement features like heterogeneous, centripetal or rim. The lesions in our discussion were subcentimeter sized and it is known that when the lesion is small, it can apparently have smooth margins and homogeneous enhancement because of limited spatial resolution of the scanner.  This was the reason for advising biopsy in our case.
As far as kinetics is concerned, three types of time intensity curves have been described by Kuhl and colleagues.  Type I is a pattern of progressive enhancement,with a continuous increase in signal intensityon each successive contrast-enhanced image. This enhancement pattern is usually associatedwith a benign finding. Its sensitivity and specificity for indication of a benign lesion are 52.2% and 71%, respectively. A Type II curve is the one with initial increase in signal intensity followed by flattening/plateau of the enhancement curve. This pattern has a sensitivity of 42.6% and specificity of 75% for the detection of malignancy. Type III, a washout enhancement pattern, involves an initial increase and subsequent decrease in signal intensity [Figure 2]D. This pattern is not usually seen in patients with benign lesions (specificity, 90.4%), but it has a sensitivity of only 20.5%.
An important and well described pitfall for a type III curve is an intra-mammary node.  Intra-mammary nodes are often recognized because of their classical reniform shape, presence of a fatty hilum and location adjacent to a main blood vessel in the breast. 
In our case, the nodules appeared rounded to ovoid in shape and didn't show any fatty hilum. On hindsight, this could be so because the nodes were showing reactive hyperplasia on pathology. The nodules were enhancing intensely and homogeneously, exhibiting type III enhancement kinetics. Though the possibility of intra-mammary nodes was raised, it was difficult to exclude possibility of recurrence solely on the basis of imaging study.
After MRI, the lesions were re-looked for in the upper outer quadrant with ultrasound (second look US).  The lesions appeared well defined, rounded and hypoechoic. After localising them undersonography with skin marking, excision biopsy was performed. This reduced the cost and time required for biopsy. Histopathology revealed reactive intrammamary nodes showing T zone hyperplasia.
Kinoshita et al. have reported reactive inflammatory intramammary lymph node mimicking malignant lesion on dynamic MRI.  Iglesias et al. also have described benign intrammamary node simulating malignancy. 
| > Conclusion|| |
case has two teaching points. Firstly reactive intrammamary node may exhibit type III enhancement kinetics, mimicking a malignant lesion. Secondly, second look US can be used to localize lesions seen on MRI.It is cheaper, faster and probably even easier to do a guided procedure using US or mammography rather than MRI.
| > References|| |
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[Figure 1], [Figure 2], [Figure 3]