The Significance of Intramammary Lymph Nodes in Breast Cancer

Abstract

Intramammary lymph nodes (IntraMLNs) are frequent mostly benign incidental findings. However, they are clinically important because they can be the primary sites of metastasis and sentinel lymph nodes. Literature data regarding the clinical significance of IntraMLNs metastasis, however, remains controversial. This study aimed to perform a systematic review and meta-analysis to better define the prognostic value of positive IntraMLNs in patients with breast cancer. A systematic review of the literature without date restrictions was conducted. Five electronic medical databases were searched, and a hand-search of the reference lists of the collected articles was also performed. Studies with sufficient and relevant pathologic and clinical survival data were included. Other studies with insufficient data or normal findings were excluded. This study found 18 studies eligible for systematic review, 3 of which were eligible for outcome meta-analysis. IntraMLNs metastases were strongly correlated with axillary lymph nodes involvement. Positive IntraMLNs are reliable predictors of axillary lymph node involvement and therefore a guide for further surgical management of the axillary nodes. Even though it could be concluded that IntraMLNs metastasis is an independent predictor of outcome, this meta-analysis was limited because of the scarcity of data and the inconsistencies and heterogeneity of the outcome studies.

The clinical significance of metastatic breast carcinoma to intramammary lymph node

“…Moreover, the higher rate of positive intra‐MLN/positive ALN might be related to the fact that a good proportion of these patients might had already presented with locally advanced disease, as we outlined above in our group of patients. Nonetheless, they concluded that a patient with positive intra‐MLN should have ALND . We have shown that positive intra‐MLN predicted positive ALN when SLN was negative in about one third of the patients.…”

“…Although the incidence has been reported to be up to 48%, other studies have shown this to occur only rarely . In one meta‐analysis that included 18 studies, the overall incidence was about 1% . The incidence of ipsilateral BC metastasis in an intra‐MLN is also variable.…”

“…The incidence of ipsilateral BC metastasis in an intra‐MLN is also variable. In the same meta‐analysis, it was reported to occur in 27% of the cases that had intra‐MLN …”

“…9,10 In one meta-analysis that included 18 studies, the overall incidence was about 1%. 11 The incidence of ipsilateral BC metastasis in an intra-MLN is also variable. In the same meta-analysis, it was reported to occur in 27% of the cases that had intra-MLN.…”

Intramammary sentinel lymph node with capsular extravasation in breast cancer

“…Their role in lymphatic drainage of breast regions is important, although it is not known if they represent true sentinel nodes or if lymphatic drainage to them comes from ectopic, independently developed pathways. Their incidence in various studies ranges between 0.7% and 48% [67] and can be found in all breast quadrants. IMLNs are involved in a variety of clinical situations, including benign situations, tumor metastases, breast lymphomas, and breast cancer, where their importance is not fully established.…”