BACKGROUND Infundibulocystic basal cell carcinoma is a recently described distinctive clinicopathologic variant of basal cell carcinoma. Histopathologic differential diagnosis among infundibulocystic basal cell carcinoma, trichoepithelioma, and basaloid follicular hamartoma has generated controversy in the literature. OBSERVATIONS Members of 2 families with multiple infundibulocystic basal ce...

Approximately 10% of patients who have a spontaneous pneumothorax have a positive family history. In 1977, Birt, Hogg and Dube (BHD) described a genodermatosis characterised by benign tumours of the hair follicle that has been associated with renal neoplasms and spontaneous pneumothorax. The BHD locus is located on chromosome 17p11.2 and is now known to be due to heterozygous germline mutations...

Dyschromatosis symmetrica hereditaria (DSH) is an autosomal dominant pigmentary genodermatosis, characterized by a mixture of hyperpigmented and hypopigmented macules that are mainly present on the dorsal portions of the extremities. The DSH locus was mapped to chromosome 1q11-q12 and, subsequently, pathogenic mutations in the double-stranded RNA-specific adenosine deaminase (ADAR1) gene were i...

Kindler syndrome is a rare, autosomal, recessive genodermatosis characterized by trauma-induced acral blisters in infancy and childhood, photosensitivity and progressive poikiloderma. Very few cases in the literature report an association with squamous cell carcinoma, even though it is a very well-known, long-term complication. A case involving a 23-year-old woman with a history of Kindler synd...

Palmoplantar keratoderma (PPK) is a heterogeneous group of hereditary and acquired disorders characterized by abnormal thickening of the palms and soles. There are three clinical patterns: diffuse, focal, and punctuate. Palmoplantar keratodermas can be divided into the following functional subgroups: disturbed gene functions in structural proteins (keratins), cornified envelope (loricrin, trans...

Epidermodysplasia verruciformis (EV) is a rare genodermatosis, first described by Lewandosky and Lutz in 1922.1 This premalignant lesion has occurred de novo, as well as in patients with impaired cell-mediated immunity, including those infected with HIV, systemic lupus erythematosus2 (SLE), or lymphoma,3 or those who have received a solid organ transplant.4 In immunocompromised and immunocompet...

Dowling-Degos disease (DDD) is an autosomal dominant genodermatosis characterized by reticular pigmented anomaly mainly affecting flexures. Though KRT5 has been identified to be the causal gene of DDD, the heterogeneity of this disease was displayed: for example, POFUT1 and POGLUT1 were recently identified and confirmed to be additional pathogenic genes of DDD. To identify other DDD causative g...

In conclusion, BSI is a rare genodermatosis belonging to the group of ARCI. It has a series of clinical and diagnostic peculiarities that we should be aware of. Although the diagnosis is usually clinical, confirmation can only be made by genetic analysis of the TGM-1 gene. This is the only gene implicated in this condition, but its mutations are also the most prevalent in other forms of ARCI, a...

Pachyonychia congenita is a rare genodermatosis that can affect the larynx. Laryngeal obstruction is very unusual with only a few cases reported. A 2-year-old girl presented with typical clinical features of pachyonychia congenita shortly after birth. At age 9 months, following an upper respiratory infection, she developed stridor and hoarseness and was found to have severe laryngeal obstructio...