Tumor entities found to be potentially Napsin A positive also included three types of neoplasia for which Napsin A expression has not yet been reported, such as follicular thyroid carcinoma (n = 2; 0.7%), urothelial carcinoma of the bladder (n = 2; 0.1%) and teratoma (n = 1; 3.1%). This evidence concerns the gene NAPSA and thyroid gland follicular carcinoma.