Clinicopathologic findings in the Bannayan-Riley-Ruvalcaba syndrome

Background: The term Bannayan-Riley-Ruvalcaba syndrome has been proposed to reflect the clinical overlap of 3 conditions previously described as separate entities, each inherited in an autosomal dominant fashion. They are the Riley-Smith, Bannayan-Zonana, and Ruvalcaba-Myhrt-Smith syndromes. Observations: We studied 2 kindreds with the Bannayan-Riley-Ruvalcaba syndrome. Characteristic cutaneous findings included multiple subcutaneous lipomas and vascular malformations, lentigines of the penis and vulva, verrucae, and acanthosis nigricans. Macrocephaly with normal ventricular size, mental retardation, central nervous system vascular malformations, intestinal polyposis, skeletal abnormalities, and thyroid rumors were the most common systemic features. A striking clinical finding in 1 patient was widespread verrucous changes or both lips that histologically showed epidermal hyperplasia with papillomatosis and hyperkeratosis. Biopsy specimens of facial papules demonstrated the histological features of both syringomas and trichilemmomas. Lentiginous hyperplasia of the epidermis with increased pigment in the basal layer and a slight increase in the number of melanocytes were seen in biopsy specimens of the penile lentigines. Conclusions: The histologic findings of both the facial lesions and the pigmented macules of the penis in the Bannayan-Riley-Ruvalcaba syndrome have not, to our knowledge, been reported previously. The similarities between the Bannayan-Riley-Ruvalcaba syndrome and Cowden disease raise the possibility of a common genetic pathogenesis for these 2 diseases.