title: Clinicopathological significance of a solid component in papillary thyroid carcinoma.
abstract: OBJECTIVE
  Solid variant of papillary thyroid carcinoma (SVPTC) is characterized by a solid component (SC) involving more than 50% of the tumour with the preservation of the classical cytological features of papillary thyroid carcinoma (PTC). However, the clinical significance of SC in PTC has been rarely examined. Herein, we investigated retrospectively the clinicopathological features of PTC with various degrees (10-85%) of SC (PTCSC).
  
  
  RESULTS
  Patients with PTCSC (n = 27) were stratified into SC-major (SC > 50% of the tumour) and SC-minor (SC < 49%) groups. The clinicopathological parameters were compared to the well-differentiated PTC (WPTC) group (n = 47). Both SC-minor (n = 18) and SC-major (n = 9) groups had increased incidence of a large-sized tumour, extracapsular extension and a high recurrence rate, compared to WPTC. Disease-free survival (DFS) of both SC-minor and SC-major was shorter than that of WPTC (P = 0.035 and P = 0.016, respectively). Overall survival was similar among all the groups. Univariate analysis revealed that SC was associated significantly with a recurrence rate (P = 0.018). Using multivariate analysis, SC appeared to be associated with a recurrence rate with borderline significance (P = 0.055).
  
  
  CONCLUSIONS
  Our findings indicate that the presence of SC in PTC, regardless of the proportion, is associated with adverse clinical parameters and a shorter DFS.
authors.affiliation: Department of Diagnostic Pathology, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Ohashi
authors.affiliation: Department of Integrated Diagnostic Pathology, Nippon Medical School, Tokyo, Japan.
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Kawahara
authors.affiliation: Department of Diagnostic Pathology, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Namimatsu
authors.affiliation: Department of Endocrine Surgery, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Takehito
authors.initials: T
authors.lastname: Igarashi
authors.affiliation: Department of Diagnostic Pathology, Nippon Medical School Hospital, Tokyo, Japan.|Department of Integrated Diagnostic Pathology, Nippon Medical School, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakatani
authors.affiliation: Department of Endocrine Surgery, Nippon Medical School Hospital, Tokyo, Japan.
authors.forename: Iwao
authors.initials: I
authors.lastname: Sugitani
authors.affiliation: Department of Diagnostic Pathology, Nippon Medical School Hospital, Tokyo, Japan.|Department of Integrated Diagnostic Pathology, Nippon Medical School, Tokyo, Japan.
authors.forename: Zenya
authors.initials: Z
authors.lastname: Naito
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000401:mortality / Q000473:pathology*; D002291:Carcinoma, Papillary; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D012189:Retrospective Studies; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology*
keywords: clinical significance; papillary thyroid cancer; solid variant