The Challenges of Diagnostic Testing

HumAdminHealth and Healing

This article on the challenges of diagnostic testing was originally published in Health & Healing in the Triangle, Vol. 21, No. 3, Health & Healing, Inc., Chapel Hill, NC, publishers.


Notes Dr. Laura Briley, of the Southern Dermatology and Skin Cancer Center in Raleigh: “The critical usefulness of diagnostic testing in providing health care cannot be over-emphasized.

“Microscope and laboratory analysis guides the information needed for diagnosis and treatment decisions,” she points out. “This technology has opened a window into the workings and pathologies of the human body. The context in which medical testing is interpreted, however, makes an important difference.

“Using the basic powers of observation is still the first step in any diagnostic process. Advancements in testing haven’t changed that,” Dr. Briley says with a smile. “When I walk into a treatment room, I am first using my clinical training, experience and skill to look and to listen. As I observe the skin, I’m getting an idea of overall appearance and composition. I’m looking for anything that immediately jumps out at me as suspicions or inconsistent in context of the overall presentation. Basal cell and squamous cell skin cancers, for example, generally make themselves known,” she says, “but melanoma can be a lot trickier to diagnose. Often, melanoma are simply flat, brown moles with no texture to them at all.

WHEN EVALUATING MOLES, COLOR IS THE KEY

“I’m also looking at color. Generally, black is bad. I am more concerned by a brown or reddish mole on a patient covered with black moles because that’s what their body produces. And, of course, I’m also listening to what the patient says,” she continues. “An area they identify may look symptom-free, but if the patient tells me it bleeds frequently or itches constantly, that’s not normal—so I’m going to biopsy.”

“Removing a small piece of tissue so it can be more closely examined is called a biopsy,” Dr. Briley explains. “The sample is sent to pathology where it is tested to determine the nature of the skin cells. Are they in fact atypical or cancerous? Or are they normal with an atypical presentation? If they are cancerous, what type of cancer do they represent, and is further excision of tissue or treatment needed?”

IMPROVING TECHNOLOGY

The technology behind the stains used to decipher various types of cancers and other atypical cells has changed over the years. “Biopsies are not a new method of testing, and neither is microscopic examination,” she notes. “Stains can be applied to determine if a cell is simply dysplastic—meaning not normal but not necessarily cancer—or if it’s a melanoma, a B-Cell cancer, lymphoma, or something else. Each stain has been specifically developed to identify and categorize the cells.

“Most often, the result of tissue I remove is ‘dysplastic,’” Dr. Briley says. “This is where the testing results have to be put in context. When the outcome of testing discovers melanoma, I take it off. When it’s dysplastic, although it’s not necessarily cancer, it may become cancer— one, five, twenty years down the road. It also may not.”

Dr. Briley also noted other relevant factors in evaluating the test results: “What is the patient’s history and family history? Are there many questionable spots or just one? What other risk factors contribute to the likelihood of skin cancer for this patient? Also, what is the patient’s preference? Many just say take it off, without question. Others may want to wait, watch the intruder carefully, and only remove it if it clearly becomes necessary to do so.”

TESTING: ONE PIECE OF THE PUZZLE

It’s also important, Dr. Briley notes, for a provider to consider that tests aren’t infallible and may miss a nuance, and therefore miss a diagnosis—even for the condition being tested for. “I had a patient who presented once with what I thought was morphea—also known as localized scleroderma. There is a test I can run to confirm this diagnosis by identifying antibodies produced in the presence of this disease. I ran the antibody test, and nothing showed up. But I really still felt it was morphea from the presentation and history.

“The choices then were to use my clinical judgment, despite the test results, or to run an extensive and expensive panel of tests hoping to get reliable outcomes.”

Dr. Briley, in conjunction with her patient, chose to treat the condition as morphea, and the condition improved over time. “Sometimes the test has all the answers,” she says, “and sometimes it’s only one piece of the puzzle.”

WHICH TEST?

Knowing which tests to order is a critical factor in the use of diagnostic testing, which speaks to the skill and training of a provider. “The skin can provide many clues to what is going on in the body,” Dr. Briley explains. “A skin rash, for example, isn’t always skin deep. A rash may be a sign of Lupus, liver disease, or a simple virus. When a patient comes in with a skin condition not easily explainable, it’s my job to figure out what’s going on. Laboratory testing is one way my investigative work is done.”

One such patient, Ann, came to see Dr. Briley after five months of dealing with a rash that had not been definitively diagnosed. Explains the doctor, “Ann had been given a steroid cream, with minimal positive results. I was suspicious of a condition called interface dermatitis, and biopsy results confirmed my suspicion was correct. This led me to order a whole panel of tests to help identify exactly what we were dealing with.”

Further testing identified the presence of a very specific antibody in Ann’s system. “Ann had drug-induced Lupus,” Dr. Briley says. “The Lupus was causing her rash, as well as a number of other symptoms such as joint pain—which she hadn’t considered as related to her rash.”

Dr. Briley reviewed all of Ann’s medications. It turned out a seizure medication Ann had been taking for years was the culprit. “I’d never seen Lupus caused by a medication someone had been taking for 20 years. There are certain medications we know can cause Lupus and we monitor closely when starting them. This presentation was new to me, however.”

Ann was taken off the offending medication and her symptoms eventually resolved. “Ann’s case was a good example of how clinical judgment and experience can be enhanced by the amazing laboratory testing we have available today, but only when you know what you are looking for, and where to start.”

Contact Southern Dermatology today if you have any concerns or questions about your skin.