Abstract
Reassessment of histological specimens of salivary gland carcinomas is associated with a change of primary diagnosis in a significant number of patients. The authors evaluated the relation between reclassification/verification of histological diagnosis and the clinical course of parotid gland carcinomas. Histological and immunohistochemical examinations of 111 specimens of parotid gland carcinomas operated on during the years 1992–2010 were revised and in some cases supplemented with cytogenetic tests (FISH), to verify the diagnosis and potentially reclassify the tumours. Analysis of the clinical documentation and follow-up data of patients whose diagnosis was changed was then carried out. The prognostic factors taken into account in the evaluation of the clinical course included the T and N stage, the tumour grade and the extent of resection. The primary diagnosis was changed on review in 28 patients (25.2 %). In 16 patients, the change involved a different histological type of cancer. In six cases, what was thought to be a primary salivary gland cancer was reclassified as a secondary tumour. In four other cases, the change was made from a malignant to a benign tumour and in one case to a non-neoplastic lesion (necrotizing sialometaplasia). Additionally, in two patients with carcinoma ex pleomorphic adenoma, the malignant component was found to be of in situ type. A potentially atypical clinical course was observed in 4 out of 28 patients whose diagnosis was changed. In the case of 2 patients, the course of disease was more aggressive (dissemination, death) than predicted and less aggressive in rest of the patients. Histological reclassification/verification of parotid gland carcinomas can explain the cause of an atypical clinical course in some patients and sometimes enables doctors to implement a change in therapy.
Highlights
Reassessment of histological specimens of salivary gland carcinomas is associated with a change of primary diagnosis in a significant number of patients
In 16 of those patients, the change involved reclassification of the salivary carcinoma from one type to another, and in 6 cases the change was to a new type of salivary gland carcinoma not recognized in the 2005 WHO classification—mammary analogue secretory carcinoma (MASC)—based on the presence of ETV6-NTRK3 translocation
Diagnosis was changed to salivary duct carcinoma (SDC), supported by positive expression of HER-2 protein
Summary
Reassessment of histological specimens of salivary gland carcinomas is associated with a change of primary diagnosis in a significant number of patients. Reclassification can involve diagnosis change from one type of cancer into another of the same or different grade and from a primary to a secondary (metastasis) tumour or from a malignant to benign lesion [8]. The last two situations are especially associated with clinical implications due to a risk of overdiagnosis and overtreatment or underdiagnosis and an inadequate treatment For this reason, the authors of this article have evaluated the relation between reclassification/verification of histological diagnosis and the clinical course of parotid gland carcinomas in a large case series
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have