How Can Dermatologists Help Dermatopathologists Work “Smarter” for Them?

Regarding biopsy technique, punches of broad neoplasms, especially possible melanoma, may give false-negative results, which includes sampling the darkest area, a practice thought to be more sensitive at detecting malignancy. In actuality, it may be an area of hemorrhage, an associated solar lentigo, or a seborrheic keratosis. Furthermore, this may produce the phenomenon of “biopsy sculpture,” turning a large asymmetrical neoplasm into a smaller sample that looks symmetrical and more benign than it actually is. If a punch biopsy is performed, it should be a broad punch (ie, >5 mm in diameter) or the entire lesion should be punched out, which represents an excision. Multiple small punches are not optimal, as a broad specimen that provides a panoramic view of the entire process is preferable. Although incision or excision specimens are excellent, they often are impractical; rather, a broad saucerization biopsy is an excellent method that provides a representative specimen in the majority of cases.

Shave specimens of inflammatory processes do not sample the lower dermis or subcutis and often are inadequate, leading to reports of “tissue insufficient for diagnosis” or “descriptive” rather than specific diagnoses. Inadequate biopsies increase expenses as well as patient inconvenience and anger. In my laboratory, we teach residents to treat the biopsy as a treasure. Some clinicians think that performing a biopsy is analogous to doing a blood test and that any tissue at all will be sufficient for a diagnosis to be rendered; however, small curettings or tiny fragments of tissue often are inadequate and place both the clinician and the pathologist at medicolegal risk.

Clinicians requesting margins on shave biopsies must understand that they are not equivalent to margins reported on elliptical excision specimens or those performed using Mohs micrographic surgery. The pathologist can only report that a neoplasm removed by shave technique “seems to be removed in these sections,” as it cannot be determined with certainty that the lesion has been completely removed using this technique.

All biopsies are prone to sampling error. Dermatopathologists often put a note on a report saying that if this specimen represents part of a larger lesion, clinical correlation is recommended to exclude sampling error, which should be known by clinicians. It is extremely risky to ask for margins on a melanoma biopsy, and one should never assume a shave biopsy of a melanoma is adequate treatment.

If a clinician is clinically concerned about a diagnosis, especially melanoma, and the histologic diagnosis is benign, it is recommended that the lesion be excised nonetheless. A final diagnosis depends on a number of clinical, histological, historical, and genetic elements and possibly others. In some cases, the clinical diagnosis is more important than the histologic diagnosis. Clinicians should always feel free to call their dermatopathologist, ask questions, and refute a diagnosis. The dermatopathologist seeks to arrive at the best diagnosis for the patient, not to be “right.”

Diagnoses should be simple and differential diagnoses few. The longer the report and the more stains that are performed, generally the less is known about the diagnosis. Diagnoses should be rendered in terms easily understood by clinical dermatologists. Get a consultant dermatopathologist that you know and trust.