Differential Diagnosis for Indeterminate 2.4 cm Lesion on Right Lobe of Thyroid
Single Most Likely Diagnosis
- Benign Thyroid Nodule (e.g., Follicular Adenoma): This is the most common cause of thyroid lesions and is often incidentally discovered. The majority of thyroid nodules are benign, and given the size and indeterminate nature, a benign nodule is a plausible initial consideration.
Other Likely Diagnoses
- Papillary Thyroid Carcinoma: This is the most common type of thyroid cancer and can present as an indeterminate lesion on imaging. The size of the lesion (2.4 cm) increases the suspicion for malignancy.
- Follicular Thyroid Carcinoma: Although less common than papillary carcinoma, follicular carcinoma is another type of thyroid cancer that could present as an indeterminate lesion.
- Hurthle Cell Neoplasm: These can be either benign (adenomas) or malignant (carcinomas) and may appear as indeterminate lesions on thyroid imaging.
Do Not Miss Diagnoses
- Medullary Thyroid Carcinoma: This rare type of thyroid cancer originates from the parafollicular cells and can produce calcitonin. It's crucial to consider due to its potential for aggressive behavior and the importance of early detection.
- Anaplastic Thyroid Carcinoma: Although very rare, this is one of the most aggressive forms of thyroid cancer. Early detection is critical, but it often presents at a more advanced stage.
- Metastasis to the Thyroid: Rarely, other cancers can metastasize to the thyroid gland. Identifying the primary source is crucial for management.
Rare Diagnoses
- Thyroid Lymphoma: Primary thyroid lymphoma is rare and usually occurs in the setting of chronic lymphocytic thyroiditis. It can present as a rapidly enlarging thyroid mass.
- Teratoma or Other Germ Cell Tumors: These are extremely rare in the thyroid and can contain elements from all three germ layers.
- Parathyroid Adenoma or Carcinoma: Although typically located near the thyroid, parathyroid lesions can occasionally be mistaken for thyroid lesions on imaging, especially if they are ectopically located within the thyroid gland.