Çağatay OYSU, Cemal Aydın GÜNDOĞMUŞ, Orhan ASYA, Ali YUMUŞAKHUYLU

Ultrasonographic and Cytological Diagnostic Difficulties of Follicular-Variant Papillary Thyroid Carcinoma

Objective: The Nuclear properties of both follicular-variant papillary thyroid carcinoma and conventional variant of papillary thyroid carcinoma are the same, but some diagnostic difficulties exist with the follicular variant. In the present study, we aimed to define the reasons for this diagnostic difficulty and raise awareness of this problem once more. Materials and Methods: In our study, we retrospectively reviewed the ultrasonographic findings and fine-needle aspiration biopsies of 104 patients whose histopathology had been surgically proven as being either the conventional or follicular-variant papillary thyroid carcinoma in a hospital between January 2012 and December 2018. Results: A highly suspicious sonographic pattern occurred in 56% of the conventional type, whereas only 21% of the follicular variant resulted in a suspicious sonographic pattern. The fine-needle aspiration biopsy of the conventional papillary carcinoma was consistent with malignancy or was suspected of malignancy in 80% of the cases, whereas this percentage was 58% for the follicular variant. Conclusion: Thus, the follicular-variant of papillary thyroid carcinoma has a higher correlation to benign sonographic features and a higher rate of false negative results via cytological examination in comparison to the conventional variant. Radiologists, pathologists, and clinicians must be aware of this situation and demonstrate care in the evaluation of nodules that appear benign.

PDF

___

Lloyd RV, Osamura RY, Klöppel G, Rosai J, Bosman FT, Jaffe ES, et al. WHO classification of tumours of endocrine organs: International Agency for Research on Cancer; 2017.
Rosai J, Carcangiu M, Delellis R. Tumors of the thyroid gland In: Rosai J, Sobin LH (eds) Atlas of Tumor Pathology, vol. 5. Armed Forces Institute of Pathology, New York. 1992:161-82.
Tielens ET, Sherman SI, Hruban RH, Ladenson PW. Follicular variant of papillary thyroid carcinoma. A clinicopathologic study. Cancer 1994;73(2):424-31.
Mesonero CE, Jugle JE, Wilbur DC, Nayar R. Fine‐needle aspiration of the macrofollicular and microfollicular subtypes of the follicular variant of papillary carcinoma of the thyroid. Cancer Cytopathology: Interdisciplinary International Journal of the American Cancer Society 1998;84(4):235-44.
Frates MC, Benson CB, Charboneau JW, Cibas ES, Clark OH, Coleman BG, et al. Management of thyroid nodules detected at US: Society of Radiologists in Ultrasound consensus conference statement. Radiology 2005;237(3):794-800.
Frates MC, Benson CB, Doubilet PM, Cibas ES, Marqusee E. Can color Doppler sonography aid in the prediction of malignancy of thyroid nodules? Journal of Ultrasound in Medicine 2003;22(2):127-31.
Yoon JH, Kim E-K, Hong SW, Kwak JY, Kim MJ. Sonographic features of the follicular variant of papillary thyroid carcinoma. Journal of Ultrasound in Medicine 2008;27(10):1431-7.
Martínez‐Parra D, Fernández JC, Hierro‐Guilmain CC, Pérez JS, Pérez‐Guillermo M. Follicular variant of papillary carcinoma of the thyroid: to what extent is fine‐needle aspiration reliable? Diagnostic Cytopathology 1996;15(1):12-6.
Baloch ZW, Gupta PK, Yu GH, Sack MJ, LiVolsi VA. Follicular variant of papillary carcinoma: cytologic and histologic correlation. American Journal of Clinical Pathology 1999;111(2):216-22.
Kini SR. Guids to Clinical Aspiration Biopsy. Thyroid. 1996.
Haugen BR, Alexander EK, Bible KC, Doherty GM, Mandel SJ, Nikiforov YE, et al. 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: the American Thyroid Association guidelines task force on thyroid nodules and differentiated thyroid cancer. Thyroid 2016;26(1):1-133.
Cibas ES, Ali SZ. The Bethesda system for reporting thyroid cytopathology. Thyroid 2009;19(11):1159-65.
Moon W-J, Jung SL, Lee JH, Na DG, Baek J-H, Lee YH, et al. Benign and malignant thyroid nodules: US differentiation—multicenter retrospective study. Radiology 2008;247(3):762-70.
Jeh S-k, Jung SL, Kim BS, Lee YS. Evaluating the degree of conformity of papillary carcinoma and follicular carcinoma to the reported ultrasonographic findings of malignant thyroid tumor. Korean Journal of Radiology 2007;8(3):192-7.
Kim DS, Kim J-h, Na DG, Park S-H, Kim E, Chang K-H, et al. Sonographic features of follicular variant papillary thyroid carcinomas in comparison with conventional papillary thyroid carcinomas. Journal of Ultrasound in Medicine 2009;28(12):1685- 92.
Caraway NP, Sneige N, Samaan NA. Diagnostic pitfalls in thyroid fine‐needle aspiration: a review of 394 cases. Diagnostic Cytopathology 1993;9(3):345-50.
BALOCH ZW, SACK MJ, YU GH, LIVOLSI VA, GUPTA PK. Fineneedle aspiration of thyroid: an institutional experience. Thyroid 1998;8(7):565-9.
Silverman JF, West RL, Larkin EW, Park HK, Finley JL, Swanson MS, et al. The role of fine‐needle aspiration biopsy in the rapid diagnosis and management of thyroid neoplasm. Cancer 1986;57(6):1164- 70.