Comparison of B-mode and Doppler ultrasonographic findings with histologic features of benign and malignant superficial lymph nodes in dogs.
OBJECTIVE
To compare and correlate B-mode and color Doppler ultrasonographic characteristics with histopathologic findings of benign and malignant superficial lymph nodes in dogs.


METHODS
50 superficial lymph nodes that were normal, abnormally large on physical examination, or represented regional lymph nodes draining an area of suspected primary malignancy in 30 dogs.


METHODS
Before excision, lymph nodes were evaluated via B-mode and color Doppler ultrasonography to assess size, echogenicity, presence of a hilus, acoustic transmission, and vascular flow. Formalin-fixed, paraffin-embedded tissue sections of excised lymph nodes were stained with H&E and examined for the presence and extent of necrosis, fibrosis, fat, metastases, and tissue heterogeneity. To assess vascularity, the number and distribution of vessels stained by the Verhoeff van Gieson technique were recorded.


RESULTS
In superficial lymph nodes, a varied echogenicity corresponded to tissue heterogeneity. The ultrasonographic detection of a hilus was associated with the presence of fibrous tissue, fat, or both in the hilar region. Acoustic enhancement corresponded to presence of areas of intranodal necrosis. There was significant correlation between both the distribution and the number of vessels detected via ultrasonography and that detected by histopathology. The amount of flow estimated via ultrasonography was typically higher than that estimated via histologic examination.


CONCLUSIONS
Results indicated that histopathologic changes in canine lymph nodes have associated ultrasonographic changes and suggest that lymph node ultrasonography has an important role in the evaluation of lymph nodes in dogs in general and in dogs with neoplastic disease in particular.
Nyman
Helena T
HT
Department of Small Animal Clinical Sciences, The Royal Veterinary and Agricultural University, 1870 Frederiksberg, Denmark.
Lee
Marcel H
MH
McEvoy
Fintan J
FJ
Nielsen
Ole L
OL
Martinussen
Torben
T
Kristensen
Annemarie T
AT
D000818:Animals; D004283:Dog Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D004285:Dogs; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008223:Lymphoma / Q000175:diagnosis / Q000662:veterinary*; D018608:Ultrasonography, Doppler / Q000379:methods / Q000662:veterinary*