Three Cases of Cancer Misdiagnosed as Chronic Lyme Disease Interview with:
Christina Nelson, MD, MPH, FAAP

Medical Epidemiologist
Centers for Disease Control and Prevention
Division of Vector-Borne Diseases | Bacterial Diseases Branch
Fort Collins, CO

Medical Research: What is the background for this study?

Dr. Nelson: Evidence-based guidelines for the diagnosis and treatment of Lyme disease have been provided by the Infectious Diseases Society of America for many years. These comprehensive guidelines have been vetted by external review panels as the best option for patient care. In endemic areas, patients with the typical rash (erythema migrans) can be diagnosed with Lyme disease clinically. Otherwise, the guidelines recommend that diagnosis be based on a history of possible exposure, compatible clinical features, and positive two-tier serologic testing.

Some patients who have been treated for Lyme disease may develop post-treatment Lyme disease syndrome (PTLDS) – fatigue, arthralgias, or other symptoms that persist after completing antibiotic treatment. Although the exact cause of post-treatment Lyme disease syndrome is unknown, it is thought to be due to an altered immune response or residual damage to tissues during the acute infection. A diagnosis of exclusion, PTLDS should only be diagnosed after the patient has been thoroughly evaluated and other potential causes of symptoms ruled out.

On the other hand, “chronic Lyme disease” is a loosely defined diagnosis that has been used to describe a variety of ailments. A small cadre of providers use unconventional methods to diagnose patients with chronic Lyme disease, and sometimes there is no objective evidence that the patient ever had Lyme disease. Multiple factors contribute to this phenomenon, including misconceptions about serologic testing, use of unvalidated diagnostic tests, and clinical diagnosis of Lyme disease based on nonspecific symptoms alone.

We know that patients have been – and continue to be – harmed by treatments for chronic Lyme disease. Patients have suffered from emboli, severe allergic reactions to antibiotics, neutropenia, and infections such as Clostridium difficile. This is terrible and should never happen. However, there is another important danger related to these alternative practices. Some patients who have been diagnosed and treated for chronic Lyme disease later discover that another condition is the root of their physical problem. We wanted to highlight some of these cases in order to help educate providers and patients about this issue.

Medical Research: What are the main findings?

Dr. Nelson: This paper describes three patients who had neoplasms (cancer or tumors) that caused symptoms that were incorrectly attributed to chronic Lyme disease.

  • Patient 1 suffered from the effects of a pituitary tumor but was incorrectly treated for chronic Lyme disease for years. Although the tumor was eventually discovered and surgically removed, he continues to undergo treatments for the physical effects of the tumor’s unchecked growth.
  • Patient 2 was treated with antibiotics for fatigue, abdominal pain, and loose stools. He was later diagnosed with Stage IV lymphoma and died two years afterward.
  • Patient 3 presented with the signs of Lyme disease and was appropriately treated. Subsequently, he continued to feel unwell and received additional courses of antibiotics. A chest X-ray months later revealed lung cancer. Fortunately, he had a good outcome once the tumor was diagnosed and surgically removed. However, further delays in recognition of his actual condition would have allowed tumor growth and possible metastasis.

Each of these patients was inappropriately treated with long-term antibiotics when their symptoms were due to another treatable condition.

Medical Research: What should clinicians and patients take away from your report?

Dr. Nelson: CDC wants people who have Lyme disease to be diagnosed and treated as quickly as possible.

On the other hand, we don’t want people to be treated for chronic Lyme disease when they are suffering from another ailment that’s gone undiagnosed. The diagnosis of any disease should come only after a thorough evaluation and exclusion of other plausible causes. When a patient does not improve or the diagnosis no longer seems likely, the responsible provider should reassess and consider other diagnoses.

Furthermore, the first two patients described in this report had worsening symptoms during treatment for presumed Lyme disease and were told that this was due to a Jarisch-Herxheimer reaction (commonly known as “herxing”). The Jarisch-Herxheimer reaction is an acute episode of fever, hypotension, or respiratory distress that occurs within 24 hours of initiating antibiotic treatment for some bacterial infections. There is no evidence that Jarisch-Herxheimer reactions cause ongoing or delayed worsening of symptoms. Patients who worsen during antibiotic treatment should be reevaluated thoroughly to exclude other disease processes.

The bottom line for patients is: if you’ve been diagnosed with chronic Lyme disease or have been treated for this and do not seem to be getting better, please consider getting a second opinion to rule out other treatable conditions. You deserve an accurate diagnosis!

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Nelson: More research on post-treatment Lyme disease syndrome is needed in order to better understand the pathogenesis of this condition and identify effective treatment options for patients. This is a difficult condition that continues to cause patient morbidity.

Also, it would be helpful to have systematic assessments of misdiagnosis and harmful treatments for chronic Lyme disease so that we can get a better handle on the magnitude of this problem. Patients continue to be harmed by unconventional approaches to diagnosis and treatment of Lyme disease.  This report and other published cases of adverse events are unfortunately only the tip of the iceberg.


Nelson C, Elmendorf S, Mead P. Neoplasms Misdiagnosed as “Chronic Lyme Disease”. JAMA Intern Med. Published online November 03, 2014. doi:10.1001/jamainternmed.2014.5426.