Abstract
Follicular Carcinoma, Clear Cell Variant is very rare among thyroid carcinomas, and is classified as a variant type of follicular carcinoma. We report a case of follicular carcinoma, clear cell variant, in which the condition progressed rapidly to death. In addition, we could perform autopsy. A 71-year-old female presented with a swelling in the anterior neck region, and was referred to our hospital. We performed fine-needle aspiration cytology of the thyroid gland and biopsy of the neck lymph nodes. The findings led to suspicion of malignancy of advanced clinical stage, however, we could not make a definitive diagnosis. The respiratory failure worsened progressively, and the patient eventually died on Day 18 of admission. Autopsy revealed that she had follicular carcinoma, clear cell variant, multiple lymph node metastasis, lung metastasis, and cancerous pericarditis. We were sure that the cause of death was cardiac tamponade. Furthermore, in both the primary and metastatic lesions, there were numerous regions showing significantly poor differentiation, suggestive of anaplastic transformation.
