Open AccessArgyrophilic Nucleolar Organizing Regions and Ki67 Equally Reflect Proliferation in Fine Needle Aspirates of Normal, Hyperplastic, Inflamed, and Neoplastic Canine Lymph Nodes (n = 101)
Author(s) -
Bauer Natali B.,
Zervos Daniela,
Moritz Andreas
Publication year - 2007
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/j.1939-1676.2007.tb03045.x
Subject(s) - medicine , pathology , lymph , hyperplasia
Background : The count of argyrophilic nucleolar organizing regions (AgNOR) has been considered a useful variable that reflects cellular proliferation in canine lymph nodes, but it has not been compared with other markers of proliferation. Hypothesis : Ki67 and AgNORs are equally useful as markers of tissue proliferation in fine needle aspirates of canine lymph nodes. Animals : A total of 101 dogs. Material and Methods : Prospective, observational study of a convenience sample of dogs. Two smears were prepared for a May‐Gruenwald‐Giemsa stain and a Ki67/AgNOR double stain. In addition, CD3/CD79a immunostaining was performed when cytologic examination revealed a lymphoma. The dogs were grouped as normal (n = 26), reactive hyperplasia (n = 25), lymphadenitis (n = 31), and lymphoma (n = 19), based on the physical examination and the cytologic findings. The AgNOR count/cell, AgNOR area/cell and the percentage of cells staining positive for Ki67 were evaluated in 100–167 cells (median, 113 cells) by using automatic image analysis. Results : Mean (SD) AgNOR counts/cell were 1.36 6 0.19 in normal dogs, 1.55 ± 0.26 in lymphadenitis, 1.65 ± 0.32 in reactive hyperplasia, and 3.67 ± 1.08 in lymphoma. The percentage of Ki67 positive cells was 2.67 ± 0.99% in normal lymph nodes, 5.04 ± 3.34% in lymphadenitis, 5.36 ± 2.14% in reactive hyperplasia, and 30.2 ± 10.8% in lymphoma. All variables were significantly higher in dogs with lymphoma compared with the other groups ( P < .0001). The sensitivity and the specificity of the AgNOR count for diagnosing lymphoma were 95 and 96% at a cutoff value of .2.04 AgNORs/cell. The cutoff value for the Ki67 positive cells was .10.40% (sensitivity, 95%; specificity, 98%). Conclusion and Clinical Importance: The results indicated that both AgNOR and Ki67 counts were good diagnostic tools for assessment of proliferation in aspirates of canine lymph nodes.