NEW YORK — Many primary care physicians are evaluating skin disorders and often relying on general pathologists to make dermatologic diagnoses, which, according to Dr. Clay Cockerell, could be a recipe for disaster.
Non-dermatologists referring skin samples to general pathologists for evaluation is like “the blind leading the blind” and often leads to misdiagnosis and poor patient care, said Dr. Cockerell at the American Academy of Dermatology's Academy 2007 meeting.
Dr. Cockerell, a dermatologist at the University of Texas Southwestern Medical Center, Dallas, said that only 35% of all skin biopsies come from dermatologists. On a day-to-day basis, dermatologists may do a lot more biopsies than their primary care counterparts, but in terms of sheer numbers, primary care physicians are doing vastly more. In addition, economic pressures may be pushing more primary care doctors to work up patients with skin diseases that, in the past, they would have referred to dermatologists.
There also is a shortage of dermatopathologists across the country. Dr. Cockerell said that the majority of young people entering the field are general pathologists looking to specialize.
The problem is that many general pathologists think that all histologic diagnoses are incontrovertible, and that what's on the slide is all that matters, he said. However, one facet of dermatology that makes it different from many other specialties is that histologically, the same disorder can look very different, depending on the anatomic site involved. The skin on certain body parts, like the elbows, knees and breasts, or any acral skin, can look and behave quite differently from skin of the arms, legs, face, or trunk. Lesions in these sites often do not show the classic textbook histology for the given disease. This is the sort of specialized expertise that primary care physicians and general pathologists often lack.
He described two cases in which lack of dermatologic expertise on both sides of the slide led to an incorrect or delayed diagnosis.
The first case involved a 65-year-old woman who came to a family physician with a solitary skin lesion. The physician, thinking it might be a basal cell carcinoma, took a shave biopsy and submitted it to a general pathology lab. The pathologist noted epidermotropism, exocytosis with atypical lymphoid cells, and a “predominance of T cells,” leading to a diagnosis of “probable mycosis fungoides.”
The primary care physician informed the patient about this diagnosis, and she immediately hit the Internet to learn more. Not surprisingly, the information she found was extremely upsetting, and—wisely, as it turns out—she sought out a second opinion. Dr. Cockerell and his colleagues looked at the lesion, which was not at all suggestive of mycosis fungoides, and then reassessed the histology. Their conclusion: benign lichenoid keratosis.
The second case involved a 36-year-old woman who had gone to a local primary care doctor for evaluation of a chronic, unresolving rash. The general pathologist who evaluated the histology came to a diagnosis of cutaneous lymphoma, which prompted a referral to an oncologist.
The woman underwent two courses of chemotherapy, which did seem to resolve the rashes immediately posttreatment. But they recurred shortly after each treatment, which struck the oncologist as atypical. The oncologist sought further intelligence at a skin tumor conference, and ultimately sent the patient to Dr. Cockerell for evaluation.
What he saw were erupted papules with necrotic areas. The histology showed a lot of atypical lymphoid cells, “but clinically, this did not really look like lymphoma. It turned out to be lymphomatoid papulosis.” The patient was promptly treated with PUVA, leading to a complete remission.
While Dr. Alex Krist, of the Virginia Commonwealth University department of family medicine, admits that the cases presented by Dr. Cockrell are concerning, he sees things differently. The management of dermatologic conditions is an integral part of primary care training, said Dr. Krist. Family physician residents have to fulfill many requirements to make sure they are proficient in the management of skin conditions. Part of the training is knowing when you can handle dermatologic conditions on your own, and when they need to be referred out.
In a study conducted by Dr. Krist and his colleagues, it was found that family physicians are just as good at managing skin conditions as dermatologists. The researchers photographed the patients, made a diagnosis and a management plan, and followed the study patients for 4 months. Two dermatologists then reviewed the patient cases (J. Fam. Prac. 2007;56:40-5).
While the study did not focus on skin cancer diagnosis, “I view [primary care physicians] as knowing what they can manage and how to help people find assistance when they need something more. If I have [patients] with melanoma, I will get them in to see a skin specialist. My role is initial diagnosis.”