Use of a 2-tier histologic grading system for canine cutaneous mast cell tumors on cytology specimens

Hergt, Franziska; Bomhard, Wolf von; Kent, Michael S. und Hirschberger, Johannes (2016): Use of a 2-tier histologic grading system for canine cutaneous mast cell tumors on cytology specimens. In: Veterinary Clinical Pathology, Bd. 45, Nr. 3: S. 477-483

Abstract

Background: Mast cell tumors (MCT) represent the most common malignant skin tumor in the dog. Diagnosis of an MCT can be achieved through cytologic examination of a fine-needle aspirate. However, the grade of the tumor is an important prognostic marker and currently requires histologic assessment. Recently a 2-tier histologic grading system based on nuclear features including number of mitoses, multinucleated cells, bizarre nuclei, and karyomegaly was proposed. Objectives: The aim of this study was to assess if the cytomorphologic criteria proposed in the 2-tier histologic grading system are applicable to cytology specimens. Methods: A total of 141 MCT specimens reported as grade I, II, or III according to the Patnaik system with both histologic specimens and fine-needle aspirates available were histologically and cytologically reevaluated in a retrospective study. Results: According to the 2-tier grading system, 38 cases were diagnosed histologically as high-grade and 103 as low-grade MCT. Cytologic grading resulted in 36 high-grade and 105 low-grade tumors. Agreement between histologic and cytologic grading based on the 2-tier grading system was achieved in 133 cases (sensitivity 86.8%, specificity 97.1%, kappa value 0.853), but 5 high-grade tumors on histology were classified as low-grade on cytology. Conclusion: Cytologic grading of MCT in the dog is helpful for initial assessment. However, the reliability of cytology using the 2-tier grading system is considered inadequate at this point. Prospective studies including clinical outcome should be pursued to further determine diagnostic accuracy of cytologic mast cell grading.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Tiermedizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 0275-6382
• Sprache: Englisch