PURPOSE: To describe the mammographic and sonographic appearance of a
pattern of spiculation of the contour of axillary lymph nodes. MATERIA
LS AND METHODS: Eleven cases of axillary nodes with spiculated contour
were prospectively identified on routine mammograms. All cases were i
n women with breast cancer. Sonograms of axillary nodes were available
in three cases. Medical records were reviewed, and histologic and nod
al histopathologic findings and patient outcome were correlated. RESUL
TS: All women had primary, invasive breast carcinoma. Although disease
was evident mammographically, four of nine women for whom the results
of the physical examination were known did not have palpable adenopat
hy. Nodes were isoto hyperdense (compared with breast parenchyma) on m
ammograms and were hypoechoic with irregular margins on sonograms. The
spiculated pattern of the nodes correlated with extension of metastat
ic tumor in axillary nodes into perinodal fat. At a mean follow-up of
17 months, one patient was dead of disease, eight were alive with dise
ase, and two were alive without disease. CONCLUSION: A pattern of spic
ulated axillary adenopathy in a patient with breast cancer appears to
be consistent with extranodal extension of tumor into perinodal fat. T
his finding suggests a biologically aggressive tumor with a poor progn
osis.