Patients with BHD syndrome usually develop benign hair follicle tumours, clinically known as fibrofolliculomas, which appear as multiple whitish papules after the age of 20. Fibrofolliculomas develop primarily on the face, but can also appear on the neck, ears and the upper torso (Menko et al., 2009). Previously, fibrofolliculomas and trichodiscomas (skin-coloured tumours occurring on the upper body) were considered hallmarks of BHD syndrome, but a recent study suggests that they may not be distinct histological entities, and that a morphological spectrum of these benign skin tumours may exist (Fujita et al., 1981; Misago et al., 2009). The number of fibrofolliculomas per BHD patient can range from under 10 to over 100 (Toro et al., 1999).
