Browsing by Author "Siironen, Päivi"

Background The subtype of the papillary thyroid carcinoma tall cell variant (TCV) has a worse prognosis than does the conventional papillary type (PTC). The new WHO 2017 classification defines a TCV as a tumor consisting of over 30% of cells that are two or three times as tall as they are wide. However, thresholds have differed. Our aim was to study how tall cells affect the prognosis of PTC patients and to determine, for such cells, a cut-off percentage. Methods Our cohort included 65 PTC patients who underwent surgery at Helsinki University Hospital between 1973 and 1996: originally 36 otherwise-matched patient pairs, eventually comprising 34 patients with an adverse outcome and 31 who had recovered. All samples were digitally scanned and scored by two investigators based on tall cell composition. The cohort was analyzed with four tall cell (TC) thresholds: 10%, 30%, 50%, and 70% with a median follow-up of 22 years. Results In survival analysis, only the 70% threshold showed a correlation with reduced overall survival (OS), disease-specific survival (DSS), and relapse-free survival (RFS). A correlation also emerged with death from PTC. In a multivariate analysis, a 70% cut-off and age at diagnosis significantly affected DSS. Conclusion A TC composition of 10%, 30%, or 50% showed no correlation with adverse outcome, and suggests that a 70% threshold should be the choice of pathologists reporting TCV. Our results thus fail to support the new WHO classification.