[Stationary trichogenic tumors (trichohamartomas, benign trichoepitheliomas and trichogenic cystic pseudotumors].

Trichohamartomas, benign trichoepiteliomas and cystic pseudotumours could be well distinguished in a group of 194 tumours. A possibility of common hamartoblastic features and transient forms does always exist. Diagnostic difficulties resulted mainly from a big number of specified units. An auxiliary separation into three subgroups is recommendable from didactic as well as practical reasons. The first subgroup comprises evident hamartoblastomas mimicking all the hair complex by their structure (hair follicle naevus, comedonic naevus, trichofolliculoma). The second subgroup comprises benign trichoepitheliomas with hamartoblastic features mimicking external hair sheath in cystology and histology (Wiener's porus pilar acanthoma, follicular poroma, tricholemmoma, folicular infundibulum tumour). Analogical cysts are in the third subgroup (epidermoid, tricholemmal, steatocystoma multiplex).