Results of histopathological revisions of major salivary gland neoplasms in routine clinical practice.

AIMS: Salivary gland neoplasms are rare and are characterised by overlapping histopathological aspects. Therefore, the assessment of the correct histopathological diagnosis can be challenging. This study evaluated the frequency of pathology consultations and revisions for salivary gland neoplasms during routine clinical practice in the Netherlands. Furthermore, the concordance and discordance rates of these revisions are presented. METHODS: The Dutch Pathology Registry (PALGA) was searched for patients that underwent a resection of a major salivary gland neoplasm between 2006 and 2016. Frequencies of pathology consultations and revisions are presented and, in order to calculate the rates of concordance and discordance, the results of the initial histopathological review were compared with the results of the revision. RESULTS: Between 2006 and 2016, 13 441 major salivary gland neoplasms were resected in the Netherlands. 90% (n=12 082) of these tumours were diagnosed as benign and 10% (n=1359) as malignant. The initial pathologist requested a consultation in 3.3% of resections (n=439). Revision of the histopathological specimen was performed in 2.6% (n=350) of cases. Revisions were discordant in 8.3%; including 5.8% of the initially benign diagnosed lesions reclassified as malignant by the second expert pathologist and 8% of the revised malignant tumours that underwent a subtype change. CONCLUSIONS: The number of discordant histopathological revisions (8.3%) emphasises the complexity of the histopathological diagnosis of salivary gland neoplasms. An increase in consultations may improve the accuracy of the initial diagnosis and thus treatment in salivary gland tumours while lowering the need for revisions and the number of discordant revisions.