Clinical Review
6. REMEMBER THE IMPORTANCE OF PROPER FIXATION AND PROCESSING
As obvious as it may sound, it is important to remember to promptly place sampled tissue in an adequate amount of formalin so that the tissue is submersed in it in the container.15 Failure to do so can result in improper fixation and will make it difficult to render an appropriate diagnosis. Conventionally, a 10:1 formalin-volume-to-tissue-volume ratio is recommended. If the “cold time”—the amount of time a tissue sample is out of formalin—is too long (> a few hours), an appropriate assessment can be impossible.
Appropriate fixation and fixation times are important because molecular testing is being increasingly used to make pathologic diagnoses.16 Additionally, aggressively manipulating a biopsy sample while extracting it or placing it in formalin can cause “crush” artifact, which can limit interpretability (see Figure 5).
7. PROPERLY PHOTOGRAPH AND DOCUMENT THE BIOPSY LOCATION
When performing a biopsy of a suspicious neoplasm, clinicians often remove all of the lesion’s superficial components, which means that at the patient’s follow-up appointment and subsequent treatments, only a well-healed biopsy site will remain. The biopsy site may be so well healed that it blends seamlessly into the surrounding skin and is nearly impossible for the clinician to identify. This problem is seen most often when patients present for surgical excision or Mohs micrographic surgery.17
To properly record the site of a biopsy for future dermatologic exams, take pictures of the lesion at the time of biopsy. The photographs should clearly document the lesion in question and should be taken far enough from the site that surrounding lesions and/or other anatomic landmarks are also visible. Biangulation or triangulation (taking a series of two or three measurements, respectively, from the site of the lesion to nearby anatomic landmarks) can be used in conjunction with photographs.
When using measurements, be as specific and accurate as possible with anatomic terms. For example, measuring the distance from the “ear” is not helpful. It would be more helpful to measure the distance from the “tragus” or the “root of the helix.” Without a properly photographed and documented biopsy site, surgical treatment may need to be delayed until the location can be confirmed.
8. GIVE THE PATHOLOGIST A PERTINENT HISTORY
Providing the pathologist with a sufficient history, including the distribution and appearance of the lesion, and how long the patient has had it, can be essential in narrowing the diagnosis or making the differential diagnoses. Things like medication use or new exposures to perfumes, lotions, or plants can be especially helpful and are often overlooked when filling out the pathology requisition form.
When warranted, phone calls are helpful. You might, for example, call the pathologist and give him or her a more detailed physical examination description or additional pertinent history that was discovered after the requisition was filled out. Providing a good history can make the difference between a specific diagnosis and a broad differential.
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