After a<unk>  is found during a physical examination, a referral to an endocrinologist, a thyroidologist or otolaryngologist may occur. Most commonly an ultrasound is performed to confirm the presence of a<unk> , and assess the status of the whole gland. Measurement of thyroid stimulating hormone and anti-thyroid antibodies will help decide if there is a functional thyroid disease such as Hashimoto's thyroiditis present, a known cause of a benign<unk> r goitre. Fine needle biopsy for cytopathology is also used.<unk> s are extremely common in young adults and children. Almost 50% of people have had one, but they are usually only detected by a physician during the course of a health examination or fortuitously discovered during the investigation of an unrelated condition. Workup of incidental<unk> s The American College of Radiology recommends the following workup for<unk> s as incidental imaging findings on CT, MRI or PET-CT: +Suggested workups by<unk>  characteristics Features Workup * High PET signal or * Local invasiveness or * Suspicious lymph nodes Very likely ultrasonography Multiple<unk> s Likely ultrasonography Solitary<unk>  in person younger than 35 years old * Likely ultrasonography if at least 1 cm large in adults, or for any size in children * None needed if less than 1 cm in adults Solitary<unk>  in person at least 35 years old * Likely ultrasonography if at least 1.5 cm large * None needed if less than 1.5 cm Ultrasound Ultrasound imaging is useful as the first-line, non-invasive investigation in determining the size, texture, position, and vascularity of a<unk> , accessing lymph nodes metastasis in the neck, and for guiding fine needle aspiration cytology (FNAC) or biopsy. Ultrasonographic findings will also guide the indication to biopsy and the long term follow-up. High frequency transducer (7–12 MHz) is used to scan the<unk> , while taking cross-sectional and longitudinal sections during scan. Suspicious findings in a<unk>  are hypoechoic, ill-defined margins, absence of peripheral halo or irregular margin, fine, punctate microcalcifications, presence of solid<unk> , high levels of irregular blood flow within the<unk>  or "taller-than-wide sign" (anterior-posterior diameter is greater than transverse diameter of a<unk> . Features of benign lesion are: hyperechoic, having coarse, dysmorphic or curvilinear calcifications, comet tail artifact (reflection of a highly calcified object), absence of blood flow in the<unk> , and presence of cystic (fluid-filled)<unk> . However, the presence of solitary or multiple<unk> s is not a good predictor of malignancy. Malignancy is only diagnosed when ultrasound findings and FNAC report are suggestive of malignancy. The TI-RADS (Thyroid Imaging Reporting and Data Systems) are sonographic classification systems which describe the suspicious findings of<unk> s. It was first proposed by Horvath et al, based on the BI-RADS (Breast Imaging Reporting and Data System) concept. Several systems were subsequently proposed and adopted by international scientific societies. Their main aims are to characterize the risk of malignancy of<unk> s to better select<unk> s to submit to fine-needle aspiration cytology. Another imaging modality, which is ultrasound elastography, is also useful in diagnosing thyroid malignancy especially for follicular thyroid cancer. However, it is limited by the presence of adequate amount of normal tissue around the lesion, calcified shell around a<unk> , cystic<unk> s, coalescent<unk> s. Fine needle biopsy Fine Needle Aspiration Cytology (FNAC) is a cheap, simple, and safe method in obtaining cytological specimens for diagnosis by using a needle and a syringe. The indications to do FNAC are:<unk> s more than 1 cm with two ultrasound criteria suggestive of malignancy,<unk> s of any size with extracapsular extension or lymph nodes enlargement with unknown source, any sizes of<unk> s with history of head and neck radiation, family history of thyroid carcinoma in two or more first degree relatives, multiple endocrine neoplasia type II, and increased calcitonin levels. However, increased calcitonin levels can also be attributable to smoking, chronic alcohol consumption, usage of proton pump inhibitors, and renal failure. The Bethesda System for Reporting Thyroid Cytopathology is the system used to report whether the thyroid cytological specimen is benign or malignant. It can be divided into six categories: + Bethesda system Category Description Risk of malignancy Recommendation I Non diagnostic/unsatisfactory – Repeating FNAC with ultrasound-guidance in more than 3 months II Benign (colloid and follicular cells) 0–3% Clinical follow-up III Atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) (follicular or lymphoid cells with atypical features) 5–15% Repeating FNAC IV Follicular<unk> /suspicious follicular<unk>  (cell crowding, micro follicles, dispersed isolated cells, scant colloid) 15–30% Surgical lobectomy V Suspicious for malignancy 60–75% Surgical lobectomy or near-total thyroidectomy VI Malignant 97–99% Near-total thyroidectomy Blood tests Blood tests may be done prior to or in lieu of a biopsy. The possibility of a<unk>  which secretes thyroid hormone (which is less likely to be cancer) or hypothyroidism is investigated by measuring thyroid stimulating hormone (TSH), and the thyroid hormones thyroxine (T4) and triiodothyronine (T3).Tests for serum thyroid autoantibodies are sometimes done as these may indicate autoimmune thyroid disease (which can mimic<unk> r disease). Other imaging Thyroid scan A thyroid scan using a radioactive iodine uptake test can be used in viewing the thyroid. A scan using iodine-123 showing a hot<unk> , accompanied by a lower than normal TSH, is strong evidence that the<unk>  is not cancerous, as most hot<unk> s are benign. Computed tomography of the thyroid plays an important role in the evaluation of thyroid cancer. CT scans often incidentally find thyroid abnormalities, and thereby practically becomes the first investigation modality.
Thyroid nodule
Thyroid cancer
Thyroid adenoma
Thyroid neoplasm
Thyroid lymphoma
Papillary thyroid cancer
Thymoma
Medullary thyroid cancer