Abstract

Goltz syndrome, or focal dermal hypoplasia, is an extremely rare X-linked dominant disorder caused by mutations in the PORCN gene. Because PORCN is involved in ectodermal development, patients usually present at birth with findings that correspond to abnormal arrangement of dermal structures and adipocytes, such as patchy cutaneous atrophy and fat herniation along Blaschko lines. The syndrome is considered an ectodermal dysplasia and is typically associated with extracutaneous manifestations, including hair, nail, ocular, and skeletal abnormalities that require a multidisciplinary approach to management. Here we present an usual case of Goltz syndrome diagnosed in an adolescent. The patient initially presented to the pediatric dermatology clinic at age seven with erythematous papules and atrophic hypopigmented plaques in a Blaschkonian distribution on the bilateral arms and legs. Skin biopsy at that time was inconclusive. Given the lack of extracutaneous findings or significant family history, genetic testing was deferred. The patient was lost to follow-up but presented to clinic nine years later with similar clinical findings. Repeat skin biopsies revealed small clusters of adipocytes and increased capillary-sized blood vessels within the papillary dermis, compatible with the Blaschkoid streaks of Goltz syndrome. These findings have previously been described in the literature but are more subtle than the classic finding of replacement of the dermis with adipocytes. This case emphasizes the importance of histopathology in the identification of Goltz syndrome. Although this disorder is rarely encountered by dermatopathologists, the recognition of subtle histopathologic clues may be crucial for diagnosis, as it was in our case.