The thyroid gland, located at the base of the neck, produces essential hormones. Lumps or growths, known as thyroid nodules, can develop within this gland. This article explores whether thyroid nodules can grow quickly and what such growth might signify.
What Are Thyroid Nodules?
Thyroid nodules are common, with prevalence increasing with age, and are often detected in adults without symptoms. Most are benign, non-cancerous growths, varying in size from a few millimeters to several centimeters.
Nodules are often discovered incidentally during imaging tests for other reasons, such as carotid ultrasounds or neck/chest CT scans. They may also be felt during a physical examination. Most do not require intervention beyond initial evaluation and monitoring.
Identifying Rapid Nodule Growth
Thyroid nodules can show rapid growth, a term clinically defined. Growth is significant if volume increases by 50% or more, or if there’s at least a 20% increase in two dimensions with a minimum 2-millimeter increase, confirmed by follow-up ultrasounds. This helps distinguish meaningful changes from minor fluctuations.
Rapid growth relies on serial ultrasound imaging, tracking the nodule’s size over time. Monitoring ultrasounds typically occur every 6 to 18 months, depending on initial characteristics. Any perceived new lump or sudden enlargement requires medical evaluation, even if it doesn’t meet clinical criteria for rapid growth.
Reasons for Quick Thyroid Nodule Growth
Several factors contribute to rapid nodule enlargement, with benign causes being more common. Hemorrhage or cystic degeneration (bleeding inside a pre-existing nodule or cyst) is a frequent benign reason for sudden growth. Inflammatory processes, like certain types of thyroiditis, can also cause temporary swelling or nodule growth.
Benign thyroid adenomas or colloid nodules can enlarge, sometimes appearing accelerated. Less frequently, rapid growth can signal thyroid cancer. Aggressive forms, like anaplastic, papillary, or follicular cancers, can cause swift enlargement. This expansion may lead to symptoms like pain, difficulty swallowing (dysphagia), hoarseness, or shortness of breath (dyspnea) if the nodule compresses nearby neck structures.
Managing Rapidly Growing Nodules
When a thyroid nodule shows rapid growth, further evaluation is needed to determine its nature. The initial step is typically a repeat ultrasound to confirm growth and assess characteristics for malignancy. A fine needle aspiration (FNA) biopsy is often recommended. This procedure collects cells for microscopic examination to determine if they are benign or cancerous.
Blood tests, such as thyroid-stimulating hormone (TSH) levels, may also evaluate overall thyroid function, though nodule growth is often independent of hormonal activity.
Management options vary based on biopsy results. If benign and asymptomatic, continued monitoring with periodic ultrasounds may suffice. For malignant, highly suspicious, or large benign nodules causing symptoms, surgical removal (thyroidectomy) is often recommended. Other treatments, like ethanol ablation for cystic nodules or radiofrequency ablation, may be considered for specific benign cases.