Diffuse sclerosing variant of papillary thyroid carcinoma with multiple metastases and elevated serum carcinoembryonic antigen level

Background: Diffuse sclerosing variant of papillary thyroid carcinoma (DSPC) is a rare variant of papillary thyroid carcinoma (PTC). We report a 61-year-old female of DSPC whose course was complicated by multiple metastases and an elevated serum carcinoembryonic antigen (CEA) level. Summary: The patient presented with upper back pain. X-ray showed an osteolytic lesion of the sixth cervical spinous process. She had a hard, nonmovable mass with fixed enlarged lymph nodes (LNs) over right neck. Fine-needle aspiration cytology revealed PTC with LNs metastasis. Positron emission tomography demonstrated multiple brain, bone, liver, and lung metastases. However, the patient had an elevated serum CEA level. She underwent a total thyroidectomy and 200? mCi radioactive ¹³¹I therapy. The pathological findings were diffuse sclerosing variant of PTC with capsular and lymph vessel invasion. A double staining of tumor specimen appeared concomitantly positive for CEA and thyroglobulin. Conclusions: To our knowledge, DSPC with an elevated CEA level is extremely rare.