Histopathologic characterization of epidermolytic hyperkeratosis: a systematic review of histology from the National Registry for Ichthyosis and Related Skin Disorders.

Background: The clinical condition generalized epidermolytic hyperkeratosis, also known as bullous congenital ichthyosiform erythroderma, is an autosomal dominant disorder and presents as a bullous disease of the newborn followed by an ichthyotic skin disorder throughout life. Clinical epidermolytic hyperkeratosis (cEHK) has characteristic histopathologic findings. Mosaic cEHK, which occurs without a family history, is a sporadic condition that clinically resembles epidermal nevi but demonstrates histopathologic findings similar to the generalized disorder; when a postzygotic mutation involves the germ line, the disease can occur in subsequent generations as generalized cEHK.

A range of histologic findings in infantile digital fibromatosis.

Infantile digital fibromatosis is a benign proliferation of myofibroblasts with characteristic eosinophilic intracytoplasmic inclusion bodies. Clinically, patients present in the first several years of life with asymptomatic, smooth, flesh-colored nodules located on the dorsal or lateral aspect of the fingers or toes. The lesions have a tendency for spontaneous regression and recur over 60% of the time following excision.

Multinucleated atypia of the vulva.

Multinucleated atypia of the vulva (MAV) is an entity with a distinctive histologic pattern of multinucleation in the basal and middle layers of the squamous epithelium that may mimic human papillomavirus (HPV)-related squamous atypias. MAV is rarely reported in the literature, and we believe it should be considered in the differential diagnosis of flesh-colored vulvar papules and vulvar epidermal atypias with multinucleated squamous cells. We describe the case of a 49-year-old patient with the diagnosis of MAV.

Localized cutaneous posttransplant Epstein-Barr virus-associated lymphoproliferative disorder.

Localized cutaneous posttransplant lymphoproliferative disorder is a rare complication of solid organ transplantation. Biopsies demonstrate diffuse dermal proliferations of atypical lymphocytes with variable Epstein-Barr virus latent membrane protein-1 expression. Extracutaneous involvement is absent.