The cytological, clinical, and pathological features of the cribriform-morular variant of papillary thyroid carcinoma and mutation analysis of CTNNB1 and BRAF genes.
BACKGROUND
The cribriform-morular variant of papillary thyroid carcinoma (CMVPTC) is an unusual subtype of papillary thyroid carcinoma. The goal of this study was to determine the clinicopathological features of CMVPTC and whether the tumor can be diagnosed by fine-needle aspiration cytology.


METHODS
We retrospectively analyzed the clinical appearance and pathological findings in five patients with CMVPTC and sequenced exon 3 of CTNNB1 and exon 15 of BRAF in tumor tissue.


RESULTS
All patients were young women, 15-34 years of age at the time of the cancer diagnosis. Preoperative cytological examination showed scattered tall columnar cells, fascicular spindle cells, and cribriform and morular patterns in the fine-needle aspirates of the thyroid from the five patients. Grossly, all tumors were well-circumscribed, solid or cystic. Immunohistochemically, most tumor cells showed nuclear expression of thyroid transcription factor-1, estrogen and progesterone receptors, and p53; cytoplasmic expression of cytokeratins 7 and 19, vimentin, and bcl-2; and cytoplasmic and nuclear accumulation of beta-catenin and galectin-3. There was no expression of thyroglobulin, cytokeratin 5/6, or human mesothelial cell-1. However, among these markers, the morular cells showed only positive immunostaining for beta-catenin, galectin-3, p53, and bcl-2. A CTNNB1 mutation was identified in only one case and no BRAF mutation was found in any of the five cases.


CONCLUSIONS
Taken together, these data suggest that CMVPTC can be diagnosed preoperatively, based on careful cytology examination, and shows unique immunohistochemical findings.
Jung
Chan-Kwon
CK
Department of Hospital Pathology, Seoul St. Mary's Hospital, The Catholic University of Korea, Republic of Korea.
Choi
Yeong-Jin
YJ
Lee
Kyo-Young
KY
Bae
Ja-Seong
JS
Kim
Hyung-Jin
HJ
Yoon
Seung-Kew
SK
Son
Young-Ik
YI
Chung
Jae Hoon
JH
Oh
Young Lyun
YL
D000231:Adenocarcinoma, Papillary / Q000175:diagnosis / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D044963:Biopsy, Fine-Needle; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D008297:Male; D008495:Medical Oncology / Q000379:methods; D010375:Pedigree; D048493:Proto-Oncogene Proteins B-raf / Q000096:biosynthesis / Q000235:genetics*; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000235:genetics*; D051176:beta Catenin / Q000096:biosynthesis / Q000235:genetics*
C495270:CTNNB1 protein, human; D051176:beta Catenin; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf