Multiple colon carcinomas in a patient with Cowden syndrome.

Cowden syndrome is a non-adenomatous gastrointestinal polyposis syndrome with inactivation of PTEN, a dual-phosphatase tumor suppressor gene. Patients with loss of wildtype PTEN expression from one allele carry an increased risk of malignant breast, thyroid and brain tumors. However, the risk of malignant transformation in gastrointestinal polyps is still unclear.

Human leukocyte antigen class II alleles and natural history of HPV 2/27/57-induced common warts.

Epidemiological studies have demonstrated an association between HLA-DQB1*03 alleles and the risk of cervical cancer induced by human papillomavirus (HPV). As persistence of HPV infection is required for developing cervical cancer, we wanted to elucidate the role of HLA-class II allele polymorphisms in the persistence of common warts induced by HPV 2, HPV 27 or HPV 57. Therefore, we determined the distribution of HLA-DQA1, -DQB1, and -DRB1 alleles in 71 patients presenting with HPV 2/27/57-induced common warts which had persisted for at least 18 months as well as in 92 individuals who had never suffered from common warts or whose warts had healed in less than 18 months.

Phenotype diversity in familial cylindromatosis: a frameshift mutation in the tumor suppressor gene CYLD underlies different tumors of skin appendages.

Familial cylindromatosis (turban tumor syndrome; Brooke-Spiegler syndrome) (OMIM numbers 123850, 132700, 313100, and 605041) is a rare autosomal dominantly inherited tumor syndrome. The disorder can present with cutaneous adnexal tumors such as cylindromas, trichoepitheliomas, and spiradenomas, and tumors preferably develop in hairy areas of the body such as head and neck. In affected families, mutations have been demonstrated in the CYLD gene located on chromosome 16q12-13 and reveal the characteristic attributes of a tumor suppressor.

Loss of heterozygosity and microsatellite instability in acquired melanocytic nevi: towards a molecular definition of the dysplastic nevus.

Acquired melanocytic nevi may show signs of histological dysplasia, and epidemiological studies have demonstrated that dysplastic melanocytic nevi (DMN) are associated with an elevated melanoma risk. Nevertheless, the concept of DMN as precursors of melanoma has remained a concept, in view of the difficulty of establishing unambiguous cytological and histological criteria for DMN. Recent molecular data suggest that genetic instability is more frequent in DMN than in benign acquired melanocytic nevi.

HPV 29-associated spotted hyperpigmentation of the face.

A healthy immunocompetent 40-year-old man presented with spotted hyperpigmentation of the face. Skin-biopsies taken from these lesions revealed slight acanthosis of the epidermis with vacuolization within the keratinocytes in the upper malpighian layer similar to HPV-induced cytopathic viral effects. Polymerase chain reaction analysis and subsequent direct DNA sequencing could clearly demonstrate the presence of HPV 29 DNA in the hyperpigmented macules.