CD200 and benign spiradenoma: Sellheyer proposed that both cylindromas and spiradenomas are adnexal neoplasms that were derived from the hair follicle bulge (CD200 positive) and that therefore cylindromas and spiradenomas represent the least differentiated follicular tumours.6 On the other hand, cylindromas at a cytomorphological level contain ductal, secretory, eccrine and apocrine glandular components suggesting that these tumours originate from very primitive sweat gland tumours.