Stretch test in basal cell carcinoma (BCC)

• technique can aid tissue sparing and avoid repeat excisions for low-risk tumours
  
  
• skin stretching technique was developed to improve the complete excision of basal cell carcinomas (BCCs)
  • stretching the skin aids in defining the borders of a BCC by emptying microvessels within the lesion
    • which reveals a pearly colour and tumour borders that contrast with the peripheral skin
      
      
  • study evidence (1) compared rates of complete excision in 596 patients who received conventional excision surgery for BCC before the stretching technique began to be employed (the control group) and 249 patients who received a pre-excision stretch test
    • rate of margin positivity after excision decreased from 6.4% in the control group to 1.7% in the stretch group
    • this study validates a procedure that many dermatologists already perform
      • stretching and pressing and stretching the tumourr skin, possibly with a glass slide, can help delineate the tumor boundaries
      • dermoscopy is preferred by some clinicians to see a magnified view of the tumor and its boundaries

The "stretch" test is useful in two ways: it aids diagnosis of BCC, and makes the tumour boundaries more obvious, helping to determine the margins for surgical excision (2).

For more information about the "stretch test" then see http://www.jprasurg.com/article/S0007-1226(02)93919-6/pdf

Reference:

• Shalom A et al. Stretch test: Effectiveness in identifying basal cell carcinoma borders. Ann Plast Surg 2012 Jan; 68:72
• Mellor RH et al. The stretch test in basal cell carcinoma: a clinical indicator of tumour. Br J Plast Surg. 2002 Oct;55(7):594-5.