Abstract
The possibility of diagnosing nodular thyroid disease by computed tomography (CT) of the body has been investigated. CT findings in 41 patients with nodular thyroid disease were compared with the pathology of the resected thyroid glands.
The results obtained were as follows:
1) An irregular wall of the tumor was observed in 80% of malignant lesions and a smooth wall of the tumor was found in 73.3% of benign lesions. A heterogeneous internal structure of the tumor was observed in 72.2% of malignant lesions. There was no correlation between homogeneous internal structure and diagnosis of benignancy or malignancy.
2) Calcification was observed in 20 out of 41 cases (48.8%). Benign lesions were revealed in 25% of the cases (4 out of 16) and malignant lesions in 64% of the cases (16 out of 25). Comma on circular calcification was usually observed in benign lesions. Scattered or coarse irregular type was frequently seen in malignant lesions.
3) Cystic degeneration was observed in 22 out of 41 cases (53.7%). Benign lesions were revealed in 87% of the cases (14 out of 16) and malignant lesions in 32% of the cases (8 out of 25). An irregular wall of the cystic degeneration was observed in 87.5% of malignant lesions and a smooth wall of the cystic degeneration was found in 92.7% of benign lesions. The patterns of cystic degeneration were classified into 3 types ; full moon, semilunar and horse shoe types. Furthermore, the full moon types were also classified into 3 subtypes; solitary, multiple and doughnut types. The data suggests that malignant lesions are easily diagnosed by recognition of an irregular wall and semilunar and horse shoe patterns, while benign lesions are diagnosed by a smooth wall and a full moon pattern. Adenomatous goiter tended to have the multiple full moon appearance.
In conclusion, CT is valuable in establishing diagnosis of nodular thyroid disease.
