Publikationsdatenbank

Mitotic Count in Canine Cutaneous Mast Cell Tumours – Not Accurate but Reproducible (2019)

Art

Poster

Autoren

Bertram, C. A. (WE 12)

Aubreville, M.

Gurtner, C.

Bartel, A. (WE 16)

Corner, S. M.

Dettwiler, M.

Kershaw, O. (WE 12)

Noland, E. L.

Schmidt, A.

Sledge, D. G.

Smedley, R. C.

Thaiwong, T.

Kiupel, M.

Maier, A.

Klopfleisch, R. (WE 12)

Kongress

Joint Congress of the European College of Veterinary Pathologists, the European Society of Veterinary Pathology, the European College of Veterinary Clinical Pathology and the European Society of Veterinary Clinical Pathology

Arnheim, Niederlande, 25. – 28.09.2019

Quelle

Journal of comparative pathology

Bandzählung: 174

Seiten: 143

ISSN: 0021-9975

Verweise

URL (Volltext): https://www.sciencedirect.com/science/article/pii/S0021997519303111

DOI: 10.1016/j.jcpa.2019.10.015

Kontakt

Institut für Veterinär-Epidemiologie und Biometrie

Königsweg 67
14163 Berlin
+49 30 838 56034
epi@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Introduction:
The mitotic count (MC) is a relevant prognostic factor in canine cutaneous mast cell tumours (ccMCTs). It is well accepted that determining MCs in the area with highest mitotic density probably correlates best with biological behaviour. However, we speculated that the selection of the areas with the highest MCs by pathologists would be inconsistent due to high variability of mitotic density within tumour sections. Therefore, we compared manual MCs with the ground truth mitotic distribution in scanned ccMCTs.

Materials and Methods:
Two pathologists labelled all mitotic figures in 28 ccMCTs in scanned slides to establish the ground truth MC distribution. In addition, 11 pathologists performed manual MCs according to current diagnostic guidelines.

Results:
Only 51.9% of all manual MCs were within the highest quartile of the ground truth distribution. Detection of the highest MC quartiles ranged from 32.1% to 82.1% among pathologists. However, classification of ccMCTs into cases with MC <7 or MC ≥7 was highly consistent among pathologists (κ = 0.865). In low MC cases, only 1/66 (1.5%) counts was falsely high. In comparison with the maximum ground truth MC, false low MCs <7 occurred in 46.5% of cases containing few areas with MC ≥7 and in 0.4% of the cases mostly containing MC ≥7 areas.

Conclusions:
The findings of this study highlight the need for further standardization of the MC such as by computerized analysis. Regardless, while pathologists commonly did not determine the MCs consistent with highest mitotic density in digital ccMCT sections, prognostication using a cut-off of MC ≥7 was highly reproducible.