Thyroid cancer. Light micrograph (LM) of a section through a thyroid gland with the clear cell variant of papillary thyroid carcinoma. (left of image).This is considered a very rare morphologic variant. The incidence of clear cell papillary thyroid cancer is estimated to be around 0.5%. The tumor cells are arranged predominantly in a mass. Approximately 80% of the tumor cells have a striking clear-appearing cytoplasm. Normal thyroid is seen on the right of the image. Magnification: x150 when printed at 10 centimetres wide. Human tissue.