Diagnostic ultrasound ( PDFDrive )

CHAPTER 21 The Breast 809
*
A
B
C
D E F
FIG. 21.73 Hallmark of Lymph Node Metastasis: Spectrum of Cortical Thickening. In A–D, the anticipated outline of a normal node is
shown in dotted line. (A) Metastases that implant near the midcortical sinusoids tend to thicken the cortex focally and equally in inward and outward
directions. (B) Metastases that implant within the subcapsular sinusoids tend to cause focal, outwardly bulging cortical thickening (“mouse ear”).
(C) Metastases that implant toward the inner part of the cortical sinusoids cause focal cortical thickenings that bulge inwardly into the lymph node
mediastinum (“rat bite” defect, *). (D) Metastases that implant extensively throughout the cortical sinusoids can cause symmetrical cortical thickening
indistinguishable from the cortical thickening caused by inlammation. (E) Cortical thickening so severe that the hilum is obliterated is usually caused
by metastasis and is strongly against the node being benign and reactive. (F) Microcalciications within a lymph node indicate metastasis until
proved otherwise, especially if the primary breast lesion has microcalciications.
A
Axilla LO MED
LT breast
B
ABN LN
Fatty LN
C
FIG. 21.74 Comparison With Adjacent Lymph Nodes to Assess Signiicance of Symmetrical Cortical Thickening. (A) When adjacent
lymph nodes within the axilla show similar degrees of symmetrical cortical thickening, the lymph nodes are more likely reactive than metastatic.
If contralateral axillary lymph nodes show similar degrees of thickening, the risk of metastasis is reduced even further. (B) If the adjacent lymph
node shows normal cortical thickness, the risk of metastasis in the node with symmetrical cortical thickening is increased. (C) When the cortical
thickening is so severe that the mediastinum of the lymph node is obliterated, the cause should be assumed to be metastatic, even when adjacent
lymph nodes are involved to a similar degree.