Single most likely diagnosis
- Thyroid adenoma with cystic degeneration: This is a common benign tumor of the thyroid gland that can undergo cystic degeneration, resulting in a mixed solid and cystic appearance on imaging.
Other Likely diagnoses
- Thyroid carcinoma (papillary or follicular): Some thyroid cancers, especially papillary thyroid carcinoma, can have a mixed solid and cystic appearance due to cystic degeneration or hemorrhage within the tumor.
- Thyroid nodules with hemorrhage: Benign thyroid nodules can undergo hemorrhage, leading to a cystic component within a solid nodule.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Anaplastic thyroid carcinoma: Although rare, anaplastic thyroid carcinoma is a highly aggressive and lethal tumor that can present with a mixed solid and cystic appearance due to rapid growth and necrosis.
- Medullary thyroid carcinoma with cystic degeneration: This rare type of thyroid cancer can also present with cystic degeneration, making it essential to consider in the differential diagnosis.
Rare diagnoses
- Thyroid teratoma: A rare type of thyroid tumor that can contain multiple tissue types, including cystic and solid components.
- Parathyroid cyst: Although not a thyroid tumor, a parathyroid cyst can be located near the thyroid gland and may be mistaken for a thyroid mass, especially if it has a mixed solid and cystic appearance due to hemorrhage or other factors.