P6.66 ALOPECIC PATCH ASSOCIATED WITH MULTIPLE PILOLEIOMYOMAS

Romaric Croes, Ruth Luyckx, Veronique Meuleman, Veronique Winnepenninckx, Joost van den Oord

University Hospitals K.U.Leuven, Belgium

A 49-year old woman presented with a nearly twenty-year history of an alopecic patch on the vertex which had recently grown in size. The patch was at times painful and itchy. There was no family history of alopecia. Clinical examination of the vertex revealed two slightly depressed coalescing patches with irregular margins and faint erythematous, atrophic and scarred appearances. The pilo-sebaceous orifices were inconspicuous and there was no perifollicular erythema at the margins of the patch. There were no other similar skin lesions present over the body. Pubic and axillary hair appeared normal. From a clinical viewpoint, the alopecic patch was inflammatory and scarring but histopathological examination of the biopsies taken from the progressing margin of the alopecic patch revealed a non-inflammatory alopecia with multiple small piloleiomyomas in the reticular dermis. In contrast to the normal appearing arrector pili muscles at the periphery of the biopsies, these piloleiomyomas were not associated with a hair follicle, but sometimes with a small and thin strand of connective tissue following the course of an anagen hair follicle. There was no concomitant cicatrising fibrosis or inflammation. Terminal hair follicles at the periphery of the biopsies appeared normal. The causal relation between the alopecia and the piloleiomyomas and the etiopathogenesis of both remain unclear. It is even unclear whether these piloleiomyomas should be regarded as real benign neoplasms, as hamartomas of the pilosebaceous unit - which is in our opinion the most likely, or as hypertrophy of the arrector pili muscles. In contrast to the classical piloleiomyomas, the piloleiomyomas in this case are relatively small and multiple and strikingly limited to the areas of alopecia. On the other hand, the arrector pili muscles in this case are obvious larger than the relatively large arrector pili muscles which sometimes can be seen in other forms of alopecia, in particular in androgenic alopecia. The progression of the alopecic patch was successfully stopped with regrowth of vellus hairs due to intralesional and local application of corticosteroids. To the best of our knowledge, this is the first report in the literature of an alopecic patch associated with multiple piloleiomyomas.