Molecular pathology represents an exciting new arena of laboratory medicine, using genetic information to augment routine histopathologic diagnosis based on morphologic characteristics. With new therapeutic interventions available for the treatment of cutaneous malignancies, the need for more accurate, earlier diagnosis is becoming essential. In fact, failure to diagnose melanoma leads the list of malpractice claims among pathologists. However, even a meticulous histopathologic analysis based on refined morphological criteria does not always permit an unequivocal diagnosis. Bastian et al review some of the molecular techniques that have the potential to play a decisive role in the diagnosis of histologically ambiguous cutaneous tumors.
Molecular pathologic assays augment those of classic laboratory medicine by providing additional diagnostic data more quickly or by providing results that would be unobtainable using standard methods. Payne et al review the molecular methods used to detect infectious agents of the cutaneous and mucosal epithelium. These methods offer rapid, highly sensitive detection of even minute numbers of infectious agents, some of which are not able to be cultured.
Keloids are proliferative fibrous growths that result from an excessive tissue response to skin trauma. Most keloids occur sporadically, but some cases are familial. Marneros et al, in the most compreshensive collection of keloid families to date, studied the clinical and genetic characteristics of 14 pedigrees with familial keloids, revealing an autosomal dominant mode of inheritance.
A genetic predisposition to the development of certain allergic disease was noted almost 100 years ago. The inheritance pattern of atopic disease is complex and does not follow the classic Mendelian patterns. MacLean and Eidelman review atopic disease-associated genes and discuss how improved diagnostic classification of atopic diseases, based on genotypic variants, could help direct appropriate therapeutic interventions.
Mounting evidence indicates that psoriasis is caused by the combined action of multiple disease-associated genes in a single individual, often triggered by environmental factors. Elder et al review the evidence that psoriasis is a genetically inherited disease of skin and discuss the current state of knowledge regarding several putative psoriasis genes. These genes provide potential molecular targets for improved drug therapies.
Understanding the structure and function of the human genome has allowed not only great advances in diagnosis, but also the potential to examine the interplay between genetics and individual reactions to drugs. Lowitt and Shear review the available genetic information related to drug toxic effects and drug efficacy.
This Month in Archives of Dermatology. Arch Dermatol. 2001;137(11):1410. doi:10.1001/archderm.137.11.1410