When is it dangerous to perform a biopsy on a skin lesion?

From the Guidelines

Biopsying a skin mass can be dangerous when the mass is suspected to be a melanoma, as biopsy may cause seeding of cancer cells and potentially worsen prognosis, and thus, an excisional biopsy with a narrow peripheral margin of 1 to 3 mm around the concerning skin lesion is recommended 1. When considering a skin biopsy, it is crucial to evaluate the potential risks and benefits, particularly in cases where the mass is suspected to be malignant. The most recent guidelines from the Journal of the American Academy of Dermatology suggest that skin biopsy remains the first step to establish a definitive diagnosis of primary cutaneous melanoma, but it should be performed with caution and consideration of alternative diagnostic approaches 1. Some key considerations include:

• The risk of misdiagnosis if a melanocytic lesion is only partially examined, highlighting the importance of excisional biopsy over incisional or partial biopsy 1
• The potential for biopsy to cause seeding of cancer cells and worsen prognosis in cases of melanoma 1
• The need to avoid biopsies in vascular lesions like hemangiomas or arteriovenous malformations due to the risk of significant bleeding
• The importance of careful evaluation of the mass's characteristics, patient's medical history, and consideration of alternative diagnostic approaches when risk factors are present
• The recommendation for excisional biopsy with a narrow peripheral margin of 1 to 3 mm around the concerning skin lesion to ensure accurate diagnosis and staging 1 In general, an excisional biopsy with a narrow peripheral margin is the preferred method for diagnosing primary cutaneous melanoma, as it allows for accurate staging and minimizes the risk of misdiagnosis or seeding of cancer cells 1.

From the Research

Biopsy Complications

• Bleeding complications can occur after a skin biopsy, especially in patients taking aspirin, with a significant increase in risk if aspirin is taken within 3 days of the biopsy 2
• Infection and scarring are also potential complications of skin biopsy, although rare 3, 4
• Hypertrophic and keloid scars can develop after a skin biopsy, especially in patients with dark skin, but can be minimized with injection of triamcinolone or verapamil into the maturing scar 4

Contraindications for Biopsy

• There are no absolute contraindications for skin biopsy, but caution should be exercised in patients with bleeding disorders or those taking anticoagulants, such as aspirin 2
• Biopsy site selection and technique are crucial to avoid misdiagnosis and complications, especially in specific diseases such as bullous diseases, vasculitis, and neoplastic disorders 5

Pre-Biopsy Considerations

• It is not necessary to discontinue anticoagulants before office-based skin biopsy, but the risk of bleeding complications should be considered 4, 2
• The choice of biopsy technique and sutures should be based on the size and location of the lesion, as well as the patient's skin type and potential for scarring 6, 3, 4