TY - JOUR
T1 - Tall cell variant of papillary thyroid carcinoma
T2 - Its characteristic features demonstrated by fine-needle aspiration cytology and immunohistochemical study
AU - Urano, Makoto
AU - Kiriyama, Yuka
AU - Takakuwa, Yasunari
AU - Kuroda, Makoto
PY - 2009/10
Y1 - 2009/10
N2 - Tall cell variant (TCV) of papillary thyroid carcinoma is a rare tumor, which is usually associated with poor outcome, and pathologists often face the dilemma of proper diagnosis of TCV, not only by cytology but also histology. To allow surgeons to determine aggressiveness of the tumor before operation, it is important for pathologists to detect tall cell features correctly by fine-needle aspiration cytology (FNAC). However, the current criteria and definition of TCV are still controversial and confounded by another problem, the differential diagnosis from poorly differentiated thyroid carcinoma (PDC). In this report, we describe two cases of TCV and present characteristic FNAC findings. The tumor cells had a peculiar shape, which included tall, columnar, and oxyphilic cytoplasm with "eccentric," basally located nuclei. We propose new terms for these cells, such as "tail-like cells" or "tadpole cells." In the surgically-resected specimens, both cases exhibited remarkable extrathyroidal invasion accompanying prominent vascular invasions. They showed high Ki-67 (MIB-1) labeling index by immuno-histochemistry, which indicated a higher proliferation activity of TCV than conventional form of papillary thyroid carcinoma. Furthermore, we discuss in this report the problematic issue of differential diagnosis of TCV from PDC and oxyphilic papillary thyroid carcinoma.
AB - Tall cell variant (TCV) of papillary thyroid carcinoma is a rare tumor, which is usually associated with poor outcome, and pathologists often face the dilemma of proper diagnosis of TCV, not only by cytology but also histology. To allow surgeons to determine aggressiveness of the tumor before operation, it is important for pathologists to detect tall cell features correctly by fine-needle aspiration cytology (FNAC). However, the current criteria and definition of TCV are still controversial and confounded by another problem, the differential diagnosis from poorly differentiated thyroid carcinoma (PDC). In this report, we describe two cases of TCV and present characteristic FNAC findings. The tumor cells had a peculiar shape, which included tall, columnar, and oxyphilic cytoplasm with "eccentric," basally located nuclei. We propose new terms for these cells, such as "tail-like cells" or "tadpole cells." In the surgically-resected specimens, both cases exhibited remarkable extrathyroidal invasion accompanying prominent vascular invasions. They showed high Ki-67 (MIB-1) labeling index by immuno-histochemistry, which indicated a higher proliferation activity of TCV than conventional form of papillary thyroid carcinoma. Furthermore, we discuss in this report the problematic issue of differential diagnosis of TCV from PDC and oxyphilic papillary thyroid carcinoma.
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U2 - 10.1002/dc.21086
DO - 10.1002/dc.21086
M3 - Article
C2 - 19373912
AN - SCOPUS:70349328250
SN - 8755-1039
VL - 37
SP - 732
EP - 737
JO - Diagnostic Cytopathology
JF - Diagnostic Cytopathology
IS - 10
ER -