Full Breakdown
Misdiagnosed Multiple Sclerosis Turns Out to Be Thyroid Cancer
By Drooid · · How we work
Misdiagnosis and Initial MS Diagnosis
In February 2025, Molly Smith, a 37-year-old mother of two from Charleston, South Carolina, experienced sudden dizziness, vomiting, and a brief loss of consciousness. Emergency physicians ordered a brain MRI to rule out head injury. The scan revealed lesions that can be associated with multiple sclerosis (MS), and subsequent testing—including a spinal tap—did not show abnormalities. Over the next year, Smith’s neurologist diagnosed her with early-stage MS and recommended disease-modifying therapy, a decision that felt serious because such treatments can carry significant side effects.
Specialized Imaging Leads to Thyroid Cancer Detection
Seeking a second opinion, Smith was referred for a more specialized MRI designed to detect MS. Rather than confirming the neurological disease, the scan identified a thyroid nodule. An ultrasound measured the lump at 6 cm, and a fine-needle biopsy indicated a roughly 50 percent chance of malignancy. The imaging results prompted surgical evaluation.
Surgical Treatment and Pathology Findings
Half of Smith’s thyroid was removed on July 30, and pathology revealed two distinct cancers: follicular thyroid cancer and papillary thyroid cancer. The American Thyroid Association notes that follicular thyroid cancer accounts for about 10 to 15 percent of thyroid cancer cases in the United States, while papillary thyroid cancer represents roughly 70 to 80 percent of cases. The cancers were confined to the nodules and had not spread to lymph nodes, allowing surgery alone to be curative. Smith will now undergo lifelong monitoring.
Reflections on Diagnostic Accuracy and Patient Advocacy
Smith’s experience underscores the importance of second opinions and thorough imaging when symptoms are ambiguous. While research indicates that most MS therapies reduce infection-related hospitalizations, they may also increase risks of thyroid disorders, liver disease, high blood pressure, heart disease, and acute liver injury. Smith emphasizes that patients should advocate for themselves, perform regular thyroid self-checks, and seek prompt evaluation of any neck abnormalities. Her story illustrates how a misdiagnosis can lead to unnecessary treatment and highlights the need for careful differential diagnosis in cases with overlapping neurological and endocrine symptoms.