Histological reclassification of parotid gland carcinomas: importance for clinicians.
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.
Department of Otolaryngology, Medical University of Gdańsk, Gdańsk, Poland. dstodulski@gumed.edu.pl.
Dominik
D
Stodulski
Department of Pathomorphology, Medical University of Gdańsk, Gdańsk, Poland.
Hanna
H
Majewska
Department of Pathology, Charles University in Prague, Faculty of Medicine in Pilsen, Pilsen, Czech Republic.
Alena
A
Skálová
Department of Otolaryngology, Medical University of Gdańsk, Gdańsk, Poland.
Bogusław
B
Mikaszewski
Department of Pathomorphology, Medical University of Gdańsk, Gdańsk, Poland.
Wojciech
W
Biernat
Department of Otolaryngology, Medical University of Gdańsk, Gdańsk, Poland.
Czesław
C
Stankiewicz
D008949:Adenoma, Pleomorphic / Q000145:classification* / Q000473:pathology* / Q000628:therapy; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000145:classification* / Q000473:pathology* / Q000628:therapy; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010306:Parotid Gland / Q000473:pathology; D010307:Parotid Neoplasms / Q000145:classification* / Q000473:pathology* / Q000628:therapy
Clinical course; Histopathology; Parotid gland carcinoma; Revision