Surgical biopsies are excisional or incisional. Excisional biopsy involves removal of an entire mass without prior knowledge of tumor type7; surgical margins may be inadequate, risking tumor regrowth, and additional aggressive surgery or adjuvant treatment (eg, radiation, chemotherapy) may be needed.7 Incisional biopsy involves excision and submission of a small piece of the tumor; this indicates the tumor type before definitive removal, and appropriate surgical margins can be planned.7
Incisional biopsies can be performed using a punch biopsy instrument, specialized biopsy needle device, or wedge technique.1,2,7 Punch biopsies of the outer layers of a subcutaneous tumor are less likely to be diagnostic because the depth of the circular blade determines the depth of the sample.7 Although needle biopsies have a high rate of diagnostic accuracy, specialized cutting needles are required and advanced imaging modalities may be needed to increase the accuracy of sample retrieval.1,2,6,7 Wedge biopsy can provide direct visualization of abnormal tissue, control of the length and depth of the sample, and avoidance of specialized equipment use.1,7
Anesthesia is not always needed for wedge biopsies; heavy sedation, analgesics, and a local anesthetic are often sufficient.