Epidermal naevus with Darier's disease-like changes in a patient with Gardner's syndrome

A Case of Cap Polyposis with Epidermal Nevus in an Infant

Cap polyposis is extremely rare in children. We report a case of an 11-month-old male infant who visited our hospital because of rectal prolapse and small amount of hematochezia lasting several days. He also had an epidermal nevus in the sacral area. Colonoscopy showed erythematous, multilobulated, circumferential, polypoid lesions with mucoid discharge from the rectum. He was diagnosed with cap polyposis by endoscopy and histologic examination. He was treated with surgical resection, and was closely followed up. In the relevant literature, there is no report of cap polyposis in an infant. We report the first case of cap polyposis in the youngest infant.

Maladie de Darier linéaire dans une fratrie

BACKGROUND

Darier's disease or keratosis follicularis is an autosomal dominant acantholytic disorder that frequently arises as a result of spontaneous mutation. It is either a generalized or localized condition due to a mutation in the SERCA2 12q23-q24,1 resulting in a faulty organization of the tonofilaments. We present two siblings affected with the linear form of this disorder and discuss these cases as an example of the genetic mechanism of loss of heterozygosity.

CASE REPORTS

A 7 year-old girl was referred for evaluation of linear lesions present since the first year of age. Examination disclosed red, 1 to 2 mm papules that coalesced to form linear plaques on the left side of the vulvar and perianal areas, and on the left hand and foot. Her older brother had similar lesions in a linear arrangement on the left side of the face neck and homolateral foot. No lesions were found in their parents. Biopsies of both affected children revealed an intraepidermal suprabasal cleft. Dyskeratotic cells were present in the spinous layer, and corps ronds and grains near the granular layer.

DISCUSSION

The linear form of Darier's disease could result from genetic mosaicism for this autosomal dominant disorder. As these children have a more pronounced involvement than the usual Darier's disease lesions, disposed in a linear arrangement, they probably represent a type 2 segmental manifestation of the disorder. Likewise, the presence of the same linear disorder in two siblings could be explained by loss of heterozygosity for the Darier's disease gene.