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Fine needle aspiration cytology of the papillary thyroid carcinoma with a solid component: A cytological and clinical correlation
Author(s) -
Ohashi Ryuji,
Murase Yukihiro,
Matsubara Miyuki,
Watarai Yasuhiko,
Igarashi Takehito,
Sugitani Iwao,
Naito Zenya
Publication year - 2017
Publication title -
diagnostic cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.417
H-Index - 65
eISSN - 1097-0339
pISSN - 8755-1039
DOI - 10.1002/dc.23679
Subject(s) - psammoma body , medicine , fine needle aspiration , pathology , cytopathology , cytology , nucleolus , thyroid , thyroid carcinoma , nuclear atypia , papillary thyroid cancer , biopsy , immunohistochemistry , nucleus , psychiatry
Background Solid variant of papillary thyroid carcinoma is a rare subtype of papillary thyroid carcinoma (PTC) containing a solid component (SC), and thus its cytological and clinicopathological features remain elusive. We examined fine needle aspiration (FNA) cytological features of PTC with variable degrees of SC (20‐80% of the tumor)(PTCSC) in comparison to well‐differentiated PTC (WPTC). Methods Twenty‐six cases of PTCSC were histologically stratified into major‐SC (SC >50% of the tumor) and minor‐SC (<49%) groups. Pre‐operative FNA smears were compared between major‐SC ( n = 11) and minor‐SC ( n = 15) groups, and between PTCSC and WPTC ( n = 39) groups . Results In FNA smears of PTCSC, the presence of cohesive solid nests, trabecular patterns, overlapping, enlarged nuclei, pleomorphism, and distinct nucleolus, and the absence of colloid and psammoma bodies were noted more often than in WPTC, while classical cytological features of PTC, such as nuclear grooves and/or pseudo‐nuclear inclusions, were preserved. There was no significant difference in FNA findings between the major‐SC and minor‐SC groups. The presence of either solid nests or trabecular patterns, and overlapping in FNA smears of PTCSC was associated with a higher recurrence rate of the tumor (P = 0.007 and P < 0.001, respectively). Conclusion PTCSC may pre‐operatively be identified by detecting its characteristic cytological features in FNA smears, regardless of the proportion of SC within the tumor. Because clinical outcomes of PTCSC remain undetermined, it is imperative to postulate PTCSC as a differential diagnosis, even when classical nuclear features of PTC are present. Diagn. Cytopathol. 2017;45:391–398. © 2017 Wiley Periodicals, Inc.