Incidence of Internal Mammary Lymph Nodes with Silicone Breast Implants at MR Imaging after Oncoplastic Surgery

Internal mammary lymph node metastasis in breast cancer patients based on anatomical imaging and functional imaging

Internal mammary lymph node (IMLN) metastasis forms part of the clinical node classification for primary breast cancer, which influences the treatment strategy. However, because of the IMLNs' complicated anatomical structures and relationships with adjacent structures, IMLN biopsy or resection is associated with a limited improvement in prognosis and a high complication rate. The positivity rate also varies broadly according to imaging modality, and there is a low rate of agreement between the imaging and pathological diagnoses, which creates imprecision in the preoperative staging. The IMLN positivity rate also varies remarkably, and there are no clear, accurate, and non-invasive modalities for diagnosing the pre-mastectomy IMLN status. Nevertheless, medical imaging modalities continue to evolve, with functional imaging and image-guided thoracoscopic biopsy of sentinel IMLNs being well established. Thus, personalized decision-making and treatment selection should be based on the modality-specific differences in the diagnosis of IMLN metastasis/recurrence and the patient's specific risk factors.

Management of MRI-Detected Benign Internal Mammary Lymph Nodes

Introduction  In this retrospective study, we aimed to evaluate benign internal mammary lymph nodes (IMLNs) in terms of frequency, number, size, long axis/short axis (L/S) ratio, intercostal location, presence of fatty hilum, and stability using breast magnetic resonance imaging (MRI) and discuss the findings by reviewing existing literature. Methods  This single-center study consisted of 130 women between the ages of 24 and 76 years, who had at least two breast MRI examinations in our institution, with the latest exam performed between January 1, 2019 and November 1, 2019, were eligible for the study. MRIs of the study group were independently reviewed by two radiologists. Results  IMLN was detected in 31.1% of the 427 MRIs, with a total number of 256 nodes. The most common indication for breast MRI was high-risk screening (66.2%). The median number of nodes per patient was 1 (range: 1-6). The median follow-up time was 19.5 months (range: 6-141 months). None of these benign nodes showed significant interval growth. Mean L/R ratio of the nodes was 1.9. One hundred and four nodes ( n  = 104, 40.6%) had a L/S ratio less than 2 and 43.2% ( n  = 45) of the nodes with a L/S ratio less than 2, had a long axis measuring less than or equal to 3mm. IMLN of patients with breast implants had the largest mean long axis. The fatty hilum was identified in 34.3% ( n  = 68) of the 256 nodes. The size of the lymph nodes where fatty hilum was visualized was significantly larger than the ones where fatty hilum was not visualized ( p  < 0.001). Fatty hilum could be visualized in only 2.7% of the nodes with a long axis smaller than 3 mm. Conclusion  IMLN is a frequent finding on breast MRI. We have shown that benign IMLNs might be large sized in specific cases like patients with breast implants. When small sized (≤3mm), they are more likely to be rounded (L/S ratio <2). The fatty hilum that is a feature of benignity might not be visualized in nodes less than or equal to3mm.

Recurrent Metastatic Breast Cancer in Internal Mammary Lymph Nodes along the Translocated Left Internal Mammary Artery Bypass Graft

Internal mammary lymph node (IMLN) is the second most common site for nodal metastases in breast cancer. The authors present a case of a 58-year-old woman with a history of coronary artery bypass graft surgery 1 year prior who presented with a neck mass. Imaging showed an enlarged IMLN along the course of the translocated left internal mammary artery (LIMA) bypass graft on the surface of the heart, and the patient was later proven to have recurrent breast cancer. To the authors' knowledge, this is the first case report in the literature of a breast cancer recurrence in an IMLN along the postoperative translocated LIMA bypass graft. Keywords: Adults, CT, PET/CT, Breast, Thorax, Lymphatic, Metastases © RSNA, 2021.

Progressive silicone lymphadenopathy post mastectomy and implant reconstruction for breast cancer

A 56-year-old woman with a 12-year history of recurrent triple-negative invasive carcinoma of the breast presented with progressive enlargement of lymph nodes in the setting of established rupture of the ipsilateral silicone breast implant. Although this was proven to be benign on cytology, its progressive nature led to repeated core biopsies for histology, which were necessary given the high-risk nature of triple-negative breast cancer and the multiple proven previous recurrences. The histology demonstrated features of silicone deposits without evidence of malignancy. This case demonstrates the dilemma in surveillance of high-risk patients with breast cancer who have had previous silicone lymphadenopathy.

Imaging and Management of Internal Mammary Lymph Nodes

Internal mammary lymph nodes (IMLNs) account for approximately 10%-40% of the lymphatic drainage of the breast. Internal mammary lymph nodes measuring up to 10 mm are commonly seen on high-risk screening breast MRI examinations in patients without breast cancer and are considered benign if no other suspicious findings are present. Benign IMLNs demonstrate a fatty hilum, lobular or oval shape, and circumscribed margins without evidence of central necrosis, cortical thickening, or loss of fatty hilum. In patients with breast cancer, IMLN involvement can alter clinical stage and treatment planning. The incidence of IMLN metastases detected on US, CT, MRI, and PET-CT ranges from 10%-16%, with MRI and PET-CT demonstrating the highest sensitivities. Although there are no well-defined imaging criteria in the eighth edition of the American Joint Committee on Cancer Staging Manual for Breast Cancer, a long-axis measurement of ≥ 5 mm is suggested as a guideline to differentiate benign versus malignant IMLNs in patients with newly diagnosed breast cancer. Abnormal morphology such as loss of fatty hilum, irregular shape, and rounded appearance (which can be quantified by a short-axis/long-axis length ratio greater than 0.5) also raises suspicion for IMLN metastases. MRI and PET-CT have good sensitivity and specificity for the detection of IMLN metastases, but fluorodeoxyglucose avidity can be seen in both benign conditions and metastatic disease. US is helpful for staging, and US-guided fine-needle aspiration can be performed in cases of suspected IMLN metastasis. Management of suspicious IMLNs identified on imaging is typically with chemotherapy and radiation, as surgical excision does not provide survival benefit and is performed only in rare cases.

Rare Cancer on the Rise: An Educational Review of Breast Implant-associated Anaplastic Large Cell Lymphoma

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare but increasingly important diagnosis as the incidence of breast implant placement, both elective and reconstructive, continues to rise. When detected and treated early, this indolent disease carries an excellent prognosis. However, because the clinical presentation is often nonspecific, it is crucial for radiologists to accurately identify the imaging findings associated with BIA-ALCL to facilitate a timely diagnosis. This article will provide radiologists with an overview of the diagnosis, imaging findings, and management of BIA-ALCL.

Incidence of benign and malignant peri-implant fluid collections and masses on magnetic resonance imaging in women with silicone implants

BACKGROUND

To assess the incidence of benign and malignant peri-implant fluid collections and/or masses on magnetic resonance imaging (MRI) in women with silicone implants who are being screened for silent implant rupture.

METHODS

The institutional review board approved this HIPAA-compliant retrospective study and waived informed consent. Women who underwent silicone implant oncoplastic and/or cosmetic surgery and postoperative implant-protocol MRI from 2000 to 2014 were included. Peri-implant fluid collections and/or masses were measured volumetrically. A benign peri-implant fluid collection and/or mass was pathologically proven or defined as showing 2 years of imaging and/or clinical stability. A malignant peri-implant fluid collection was pathologically proven. Incidence of peri-implant fluid collections and/or masses and positive predictive value (PPV) were calculated on a per-patient level using proportions and exact 95% confidence intervals (CIs). Fisher's exact test was used in the analysis to test statistical significance pre-defined as P-value < 0.05.

RESULTS

A total of 1070 women with silicone implants were included (mean age, 50.7 years; range, 40.4-53.8). Median time between reconstructive surgery and first MRI was 88.9 months (range, 0.8-1363.3). Eighteen women (1.7%) had a peri-implant fluid collection and/or mass: 15/18 (83.3%) had adequate follow-up; and only 1/15 was malignant implant associated anaplastic large cell lymphoma, with a PPV of 6.7% (95% CI: 0.003-0.0005). The median peri-implant fluid collection size was 89 mL (range, 18-450 mL).

CONCLUSION

Peri-implant fluid collections and/or masses identified at silicone implant protocol breast MR imaging are rarely seen 24 months after reconstructive surgery. Image-guided fine-needle aspiration with flow cytometry may be warranted to evaluate for implant-associated lymphoma.

Internal mammary lymph node metastases in breast cancer: what should radiologists know?

The internal mammary lymph node (IMLN) chain is a pathway through which breast lymphatic drainage flows. The internal mammary lymphatic vessel runs around the internal mammary artery and veins with IMLN in the parasternal intercostal spaces. IMLN metastasis, which forms a part of clinical TNM staging, may negatively affect the prognosis of primary breast cancer patients. IMLN metastasis is clinically detected using ultrasound, computed tomography, magnetic resonance imaging, and ¹⁸F-deoxyglucose positron emission tomography computed tomography. The uptake of radioactive tracers in IMLN with clinically negative axillary lymph nodes is often identified using sentinel lymph node mapping (SLNM) in primary breast cancer patients. The indication for IMLN biopsy or resection that is clinically detected or visualized using SLNM is controversial. The clinically suspicious IMLN may be considered for ultrasound-guided fine-needle aspiration. First IMLN recurrence needs to be biopsied. Irradiation of the breast, chest wall, and/or regional nodal irradiation, including IMLN, following lumpectomy or postmastectomy is recommended. Although radiation therapy for IMLN recurrence may improve clinical outcomes, it is also associated with pulmonary and cardiac toxicities. This review covers the local anatomy of IMLN, lymph drainage and image findings of IMLN with a discussion.

Silicone Implant Incompatibility Syndrome: Mimicking Metastases on Fluoro-Deoxy-Glucose Positron Emission Tomography-Computed Tomography in a Treated Case of Carcinoma Breast

Silicone implant incompatibility syndrome (SIIS) has been identified as a cause of systemic symptoms such as lymphadenopathy, myalgia, and dyspnea in patients with silicone implants. We present a case of 76-year-old female patient, treated for carcinoma left breast with mastectomy and silicone breast implant, chemotherapy, and radiotherapy 42 years ago. There was a history of implant rupture and removal 2 years ago. The patient presented with right axillary swelling and dyspnea. 18-fluorine fluoro-deoxy-glucose positron emission tomography/computed tomography (F-18 FDG PET-CT) showed mildly FDG-avid left anterior chest wall and right rectus abdominis deposits, multiple lymph nodes, and low-grade FDG-avid pneumonitis changes in both lungs. Biopsy from the chest wall and rectus abdominis deposit was negative for malignancy and revealed foamy histiocytes and foreign-body giant cell reaction, indicative of SIIS. SIIS is a mimic for metastases and should be considered as a differential diagnosis in FDG PET-CT interpretation in patients with silicone breast implant.

Imaging findings of mammary and systemic silicone deposition secondary to breast implants

In patients with silicone breast implants, implant rupture can occur, which can be intra- or extracapsular. Following implant rupture, silicone can travel through the lymphatic system into regional and distant lymph nodes. The purpose of this pictorial essay is to present findings of silicone implant rupture with intramammary and systemic silicone deposition as seen on dual energy CT, ultrasound, mammogram, PET/CT and MRI. We include imaging findings of silicone deposition in the breast in cases of intra- and extracapsular rupture. We also present silicone deposition in mediastinal, axillary, and internal mammary lymph nodes, as well as in the liver and spleen. To our knowledge, deposition of silicone in the liver and spleen has not been previously demonstrated on cross-sectional imaging. While all imaging modalities were able to detect silicone in the spleen, ultrasound appeared to be more sensitive than dual energy CT or MRI for detection of silicone deposition in the liver.

Metastatic internal mammary lymph nodes or mimickers on parasternal ultrasonography: focusing on their distribution and depth

Background Ultrasonography (US) is an important tool to evaluate the status of internal mammary lymph node (IMN). US features of metastatic IMNs could help determine when biopsy should be performed. Purpose To compare US features of metastatic IMNs to those of benign entities. Material and Methods In women with suspected IMN metastasis on US, their intercostal space (ICS) abnormalities were classified into metastatic IMN, benign IMN, and lymph node (LN) mimickers. US features, distribution, and depth of abnormalities in one ICS and involved ICS level were analyzed. Results Among 66 ICS abnormalities in 53 women, 46 were metastatic IMNs, ten were benign IMNs, and ten were LN mimickers. For metastatic IMNs, the second ICS was the most commonly involved ICS (n = 22), followed by the first (n = 13), the third (n = 8), and the fourth (n = 3). ICS level distribution of metastatic IMNs was not significantly ( P = 0.5407) different from that of non-metastatic lesions. Metastatic IMNs were predominantly seen in the posterior layer of ICS, significantly ( P < 0.0001) different from LN mimickers. Both metastatic IMNs and non-metastatic lesions were evenly distributed over the upper, middle, and lower part (in craniocaudal direction) of one ICS. Conclusion Metastatic IMNs are more likely to be found in the posterior layer of ICS. This can help distinguish them from LN mimickers. Any part (upper, middle, or lower) of one ICS in craniocaudal direction could be involved. The second ICS was the most commonly involved level.

Internal Thoracic Lymphadenopathy in Breast Cancer

The internal thoracic (IT) nodal basin is a first-echelon drainage pathway in the breast, accounting for up to a quarter of its lymphatic drainage, primarily from the deep structures of the breast. The presence of internal thoracic node (ITN) metastases upstages the breast cancer (BC) patient to a minimum of clinical stage III disease. Medial tumors, deep tumors, young age, axillary nodal metastases, tumors of a high nuclear grade, lymphovascular invasion, and triple-negative hormone receptor status are predisposing factors for ITN metastases from primary BC. It has been observed that medial tumors carry a worse prognosis than lateral tumors when all other factors are equal, indicating that understaging of ITN has a significant impact on patient outcomes. Despite the established prognostic significance of IT adenopathy in BC, this nodal basin is not routinely staged due to the difficulty in accessing it and due to the controversy regarding its management. Since the initial ITN studies in the 1960s, improvement in imaging techniques and the availability of minimally invasive biopsy techniques have fueled renewed interest in ITNs and their clinical significance in BC. Radiologists who image and diagnose BC can offer more accurate staging assessments by consistently evaluating the IT nodal chain in the BC patient. In this article, the authors discuss current knowledge of the ITNs in BC and review ITN anatomy. The imaging appearance of pathologic ITNs using various modalities, potential mimics of IT adenopathy, and image-guided sampling techniques are described. A succinct discussion of the clinical management of ITN-positive BC and its challenges is also included. ^© RSNA, 2017.

Review of breast augmentation and reconstruction for the radiologist with emphasis on MRI

It is imperative to continue screening for breast cancer and/or detect tumor recurrence in patients after they have undergone breast augmentation or reconstruction. As there is an increasing role for both screening and diagnostic imaging of the post-operative breast, it is important for the radiologist to be familiar with the commonly performed surgical techniques in breast augmentation and reconstruction. Imaging of the augmented and reconstructed breast, as well as complications, will be reviewed with a focus on Magnetic Resonance Imaging (MRI).

Internal mammary lymph nodes radiotherapy of breast cancer in the era of individualized medicine

Inclusion internal mammary lymph nodes as a part of regional nodal irradiation have a potential to reduce local recurrence, distant recurrence, and improve survival in breast cancer. However, the increased risk of cardiac toxicity and lungs injure associated with internal mammary lymph nodes irradiation has drew more and more attention. Estimating risk of metastasis in internal mammary lymph nodes based on axillary lymph nodes metastasis status is not always reliable: low-risk do not always mean negative in internal mammary lymph nodes and high-risk do not always indicate positive in internal mammary lymph nodes. Inaccurate prediction of in internal mammary lymph nodes metastasis might lead to over- or under-treatment of in internal mammary lymph node. Internal mammary sentinel lymph node biopsy is a minimally invasive technique which has a high potential to accurately evaluate the metastasis status in in internal mammary lymph nodes and improve accuracy of nodal staging. This technique might be a useful tool to guide individualized internal mammary lymph nodes irradiation.

FDG-PET/CT in the Postoperative Period: Utility, Expected Findings, Complications, and Pitfalls

FDG-PET/CT as a modality is increasingly used for detection of recurrence and for restaging in patients with clinical suspicion of malignancy, as well as in patients with elevated tumor markers. However, there are many pitfalls in the interpretation of these scans when the studies are performed after some treatment. Some of these are attributed to normal physiological distribution and are compounded when there are inflammatory changes occurring after surgery. The body's inherent response to the surgical insult results in this inflammation. In addition, there are also complications that can happen following surgery, causing increased FDG uptake. Despite various fallacies, FDG-PET/CT provides valuable information in evaluation of residual and recurrent malignant disease. In this article, we aim to describe some of these postsurgical changes secondary to inflammation, common surgical complications, and finally, the utility of FDG-PET/CT in these patients to detect recurrent disease, even in the background of postsurgical changes.