J Korean Soc Radiol.  2011 Jan;64(1):17-24. 10.3348/jksr.2011.64.1.17.

Computed Tomography Features of Follicular Thyroid Carcinoma: Comparison with Papillary Thyroid Carcinoma

• Lee HG
• Choi YJ
• Chung EC

• KMID: 1443577
• DOI: http://doi.org/10.3348/jksr.2011.64.1.17

Abstract

PURPOSE
The purpose of this study is to analyze the computed tomography (CT) features of follicular thyroid carcinoma (FTC) as compared to those of papillary thyroid carcinoma (PTC) to identify the characteristic imaging features of FTC.
MATERIALS AND METHODS
The following CT features were analyzed to compare FTCs (n = 17) and PTCs (n = 27): size, shape, margin, internal composition, calcification, enhancement homogeniety, extrathyroidal extension, lymph node (LN) metastasis and the density and degree of enhancement (qualitatively and quantitatively).
RESULTS
There were no significant differences between the patients with FTCs and those with PTCs with respect to age and gender, and the internal composition, calcification and enhancement homogeneity of the tumor. However, the FTCs tend to show a larger size (32 mm vs. 15 mm; respectively, p < 0.001), a round to oval shape (52.9% vs. 14.8% respectively, p = 0.001), a well-defined smooth margin (58.8% vs. 14.8% respectively, p = 0.009), less extrathyroidal extension (11.8% vs. 51.9% respectively, p = 0.007) and less LN metastasis (0% vs. 29.6% respectively, p = 0.016) compared to that of the PTCs. Furthermore, the FTCs showed significantly stronger enhancement in the early phase (146.4+/-42.4 vs. 98.5+/-38.2 respectively, p < 0.001) and a greater decrement of the late enhancement (-44.6+/-25.2 vs. -18.7+/-27.9 respectively, p = 0.003) compared to that of the PTCs.
CONCLUSION
FTCs had a tendency to be observed on neck CT as well-defined, smooth, round to oval nodules with strong early enhancement and a definite decrement of late enhancement as compared to the PTCs.

MeSH Terms

Adenocarcinoma, Follicular
Carcinoma
Factor IX
Humans
Lymph Nodes
Neck
Neoplasm Metastasis
Thyroid Gland
Thyroid Neoplasms
Thyroid Nodule
Tomography, X-Ray Computed
Carcinoma
Factor IX
Thyroid Neoplasms

Figure

• 

  Fig. 1 Follicular thyroid carcinoma proven by surgical resection On the unenhanced CT (A), a well-defined smooth round to oval hypodense mass (*) is seen in the left lobe of the thyroid gland. On the early (B) and delayed phases (C), the mass (arrowed) shows strong enhancement relative to the thyroid parenchyma.

• 

  Fig. 2 Papillary thyroid carcinoma proven by surgical resection On the unenhanced CT (A), an ill-defined or irregular taller than wide hypodense mass (*) is seen in the left lobe of the thyroid gland. In the early (B) and delayed phases (C), the mass (arrowhead) shows less enhancement relative to the thyroid parenchyma. On the coronary MPR image (D), the mass shows definite extrathyroidal extension (arrows).

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