Skin biopsy

Specimen:

Punch, shave or excisional skin biopsy. 

Skin fibroblast culture requires fresh tissue transported in sterile culture medium at room temperature (consult laboratory staff). 

Fresh tissue from edge of lesion in sterile container for microbiology.

Method:

Fresh tissue: for frozen section, immunofluorescence and molecular genetics.

Fixed tissue: for light microscopy, immunohistochemistry, electron microscopy (special fixative). 

Immunofluorescence and/or immunohistochemistry: for diagnosis of bullous lesions, lymphoid neoplasms, Henoch-Schonlein purpura and SLE;

microscopy (Gram stain, stains) for Mycobacterium spp; 

culture for bacteria and fungi; and

chemical, cytogenetic or molecular genetic studies on cultured fibroblasts.

Application:

Investigation of skin lesions including rashes, bullous lesions, ulcers, tumours. 

Investigation of some genetic disorders.

Interpretation:

Categorisation of inflammatory or infective (eg, atypical mycobacterial) dermatoses, typing of bullous lesions, connective tissue diseases and vasculitis. 

Categorisation of naevi and other forms of benign neoplasia. 

Identification of type, grade and stage of malignant tumours. 

Fibroblast studies may allow precise diagnosis of specific genetic disorders.

Reference:

Weedon D. Weedon's Skin Pathology. 3rd ed. 2009. Churchill Livingston.