Comparison of first-opinion and second-opinion histopathology from dogs and cats with cancer: 430 cases (2001-2008)

Abstract

Second-opinion histopathology is intended to detect clinically significant discrepancies that have a direct impact on patient care. We sought to determine if this practice at our institution affected patient management and prognosis. First- and second-opinion histopathology reports from cases were retrospectively reviewed. Reports were considered to be in diagnostic agreement, partial diagnostic disagreement or complete diagnostic disagreement. Four hundred and thirty cases were studied. In 70% of cases there was a diagnostic agreement. In 20% of cases, there was partial diagnostic disagreement, where diagnoses were the same but information such as grade or lymphatic and/or vascular invasion was changed. In 10% of cases, complete diagnostic disagreement resulted from a change in degree of malignancy (malignant to benign, or converse; 7%) or a change in cell type (3%). In 17% of the cases evaluated, the histopathology review prompted a change in treatment or prognosis. These findings support the use of second-opinion histopathology as an important part of patient care.

A prospective evaluation of the impact of second‐opinion histopathology on diagnostic testing, cost and treatment in dogs and cats with cancer

“…In our previous 7‐year retrospective study of 430 canine and feline tumour biopsies with first‐opinion and second‐opinion histopathology, we found a discrepancy rate of 30%; 10% of cases had complete diagnostic disagreement such as a change from benign to malignant, or vice versa, or change in cell of origin. Pathology review might have changed treatment and/or prognosis in 17% of the cases . Because of the retrospective nature of the study, however, there was limited follow‐up in many cases and it could not be determined if discordances actually changed the treatment and/or prognosis of patients.…”

Morphological Distinction of Histiocytic Sarcoma from Other Tumor Types in Bernese Mountain Dogs and Flatcoated Retrievers

“…In the group of sarcomas, it was not always possible in this study to further characterize them after being excluded as of histiocytic origin. In an earlier comparison by Regan et al of first and second opinion histopathology of 430 tumors in dogs, 30% of diagnoses (18). In their study, four tumors (two sarcomas, one round cell tumor and one plasma cell tumor became HS and two HS cases became another diagnosis (one T-cell lymphoma and one melanoma).…”

“…This stresses the need for high and uniform certification standards and standardized diagnostic criteria and workup for veterinary clinical and anatomic pathologists, and that review and (randomized) second opinion pathology/cytology and revision is recommended. Complete clinical information could further help to increase diagnostic accuracy (18). In human medicine, second-opinion tumor histopathology is already recommended as standard practice, before treatment is requested, to avoid unnecessary or inappropriate treatments.…”

Surgical margins in the veterinary cancer patient

“…Significant interpathologist variation has been demonstrated in MCT and STS grading . Variability in pathologists' interpretation regarding vascular invasion as well as absolute margin status has also been demonstrated …”

“…By definition, accurate interpretation requires reliable identification of both the tumour edge or infiltrative cells and the surgically incised edge. Although much veterinary literature presents histologic margin status categorically, margin interpretation can carry its own set of challenges and potentials for subjective and inconsistent interpretation . For example, conventional histopathology might not accurately represent margins in tumours with discontinuous growth patterns .…”