A medical diagnosis isn't always black and white. Indeed, it's often clouded by shades of gray. Some diseases begin with symptoms so subtle or common that they confound even experienced doctors. Other times, a patient knows exactly what's wrong but can't decide which treatment is best.
Enter the second opinion. It's never a bad idea to seek a second opinion, but if you receive one of these five diagnoses, it's practically a must.
1. Unusual or Hard-to-Diagnose Cancers
If you've been diagnosed with an uncommon cancer -- or if there's any question about whether it's truly cancer -- seek a second opinion from a pathologist who has expertise in diagnosing this type of malignancy. After all, the diagnosis will determine which treatment is best.
"There are certain kinds of tumors that provide a lot more difficulties in diagnosis," says John E. Tomaszewski, MD, FASCP, vice chairman of Anatomic Pathology-Hospital Services at the University of Pennsylvania School of Medicine. For example, sarcomas -- an uncommon cancer of soft tissues, such as muscle or fat -- can be complex to classify. "A general pathologist may not see a lot of soft-tissue tumors," he says.
Major medical centers that see larger numbers of rare or unusual tumors are often a better choice for a second opinion than a smaller hospital, according to John S.J. Brooks, MD, FASCP, president of the American Society for Clinical Pathology. "These folks that have very rare tumors, [a hospital] near them may only see very few," he says.
Getting that second opinion can help catch errors.
"Anytime there's uncertainty, it's always fine [to get a second opinion]," Tomaszewski says. "Pathology ... is like every other area of medicine. There are things that are very clear and things that are on the borderline."
2. ADHD in Children Under Age 6
With no specific lab test for attention deficit hyperactivity disorder (ADHD), the problem can be tough to diagnose accurately. A doctor's judgment comes into play; he or she may diagnose ADHD if a child shows hyperactivity, inattention, and impulsivity in at least two settings, such as home and school.
When a child under age 6 is diagnosed with ADHD, parents may want a second opinion from a specialist, such as a child psychiatrist, says Sara Rizvi, MD, assistant professor of pediatrics at the Baylor College of Medicine. That's because ADHD symptoms, such as too much talking or fidgeting, can overlap with behavior that's typical among young children.
"Many of the symptoms are common among preschool children," Rizvi says. "Part of it is because of their developmental stage and level of activity and normal short attention spans." A second opinion can help determine if symptoms are serious enough to be classified as ADHD.
It's also crucial to rule out other mental disorders that can be confused with ADHD, according to Rizvi. These include developmental problems, learning disabilities, anxiety, and depression. Sometimes, children who witness domestic violence may behave in ways that suggest ADHD, Rizvi says. "They tend to be more inattentive to their class work, more impulsive. A lot of those children are actually misdiagnosed with ADHD when in fact they may be manifesting symptoms of posttraumatic stress disorder."
3. Parkinson's Disease
"Parkinson's is one of the most difficult diseases to diagnose. There's no blood test, X-ray, or instrument that would give you an answer," says Executive Director Robin Elliott of the Parkinson's Disease Foundation.
Diagnosis of this neurological disorder -- marked by tremors, slow movement, muscle stiffness, and loss of balance -- is based "not on a very specific test, but a cluster of features," says David C. Dale, MD, president of the American College of Physicians. Parkinson's can be especially difficult to diagnose in the early stages.
The rate of misdiagnosis among people with Parkinson's may be as high as 25%-30%, Elliott says. In the elderly, the trembling and movement problems of Parkinson's may be dismissed as normal aging. Conversely, patients may be wrongly diagnosed with Parkinson's when their symptoms actually stem from side effects of drugs they're taking, such as certain psychiatric medicines.
Even well-trained internists and general neurologists can have trouble diagnosing Parkinson's disease, especially if they've had little experience with the disorder, according to Elliott. As a result, the Parkinson's Disease Foundation suggests that people diagnosed with Parkinson's consider getting a second opinion from a neurologist who specializes in movement disorders and has extensive experience with Parkinson's.
4. Heart Procedures
What prompts heart patients to seek second opinions?
"Probably the most common situation is that someone has been advised to have open heart surgery or a coronary intervention or a catheterization, and they're wondering if they really need that," says David L. Rutlen, MD, vice chairman of ambulatory programs at the Froedtert and Medical College of Wisconsin, which has a cardiac second opinion program. In other words, patients want extra advice before consenting to invasive heart procedures that carry serious risks, such as blood clots, stroke, infection, and even death.
A second opinion makes sense "if the patient has any concern that this is a treatment plan that may not be best for them," Rutlen says. For example, patients may wonder whether they truly need bypass surgery or if, instead, they can undergo balloon angioplasty to open up blocked arteries.
Some patients also seek out a second opinion in hopes of finding an expert with greater experience in performing the procedure they require, Rutlen says.
Also, if a patient remains undecided after the first cardiologist has listed multiple treatment options, "a second opinion from another cardiologist would be an excellent consideration," Rutlen says.
5. Depression and Bipolar Disorder
Primary care physicians often diagnose cases of depression, but sometimes a second opinion from a psychiatrist is in order.
If patients diagnosed with depression don't improve after trying at least a couple of antidepressants, or if they develop adverse effects, such as mania, they may actually have bipolar disorder, says Florence Kim, MD. She is a psychiatrist and director of the Menninger Clinic's Comprehensive Psychiatric Service, where patients can obtain psychiatric second opinions.
Why do the two disorders become confused? Some patients with bipolar disorder -- also called "manic-depressive illness" -- don't have a manic episode early on, so it's easy for doctors to mistake the two diseases. In fact, patients with a less severe form of bipolar disorder may never develop intense mania, but instead have milder manic episodes that alternate with depression.
In fact, as many as 69% of bipolar patients may receive a wrong initial diagnosis, according to Mark Graber, MD, chief of the medical service at the VA Medical Center in Northport, N.Y. Graber has done research to find ways to reduce diagnostic errors.
A proper diagnosis matters. Doctors treat depression with drugs such as antidepressants, while bipolar disorder typically requires mood stabilizers, such as lithium, either alone or in combination with antidepressants. When bipolar patients take antidepressants alone, they're at risk of switching into mania or developing rapid cycling between the highs and lows.
"I'm actually all for psychiatric intervention in the primary care setting," Kim says. "I think it's perfectly reasonable to try an antidepressant, but people just have to be educated. They have to know that if they're having adverse effects to the medication that they should see a psychiatrist. Or if they do start to feel manic effects from the antidepressants, they should see a psychiatrist."
But some patients balk, Kim says. "You almost have to hit them over the head to go to a psychiatrist. They would rather tough it out with their primary care physician because that way, they don't have to tell people they have psychiatric problems."