Wednesday 4 July 2007
Definition : Thyroid nodules are a very common clinical finding, and although the majority of them are benign, thyroid carcinoma accounts for about 5-15% of nodules.
Fine-needle aspiration cytology (FNAC) is actually used for the differential diagnosis of these lesions.
Translucent thyroid nodules are colloid rich, very probably benign
Although in most cases this examination clearly distinguishes benign from malignant lesions, some fine-needle aspiration (FNA) samples fall into undetermined thyroid cytology categories, which according to the most recent classification of thyroid FNAC consist of ‘suspicious for malignancy’, ‘suspicious for follicular or Hurtle cell neoplasm’, and ‘follicular lesion of undetermined significance/atypia of undetermined significance’.
Moreover, some samples are insufficient for diagnosis. Taken together, these categories account for almost 20-30% of nodules.
Owing to the high risk of papillary thyroid carcinoma, patients with lesions that are ‘suspicious for malignancy’ are currently subjected to lobectomy or total thyroidectomy.
On the other hand, patients with ‘atypia of undetermined significance’ undergo repeated FNAs, and patients with ‘suspicious for follicular or Hurtle cell neoplasm’ are subjected to diagnostic lobectomy and subsequently, in the case of histological diagnosis of carcinoma, total thyroidectomy.
thyroid macroscopical anomalies
Fine-needle aspiration of follicular lesions of the thyroid. Diagnosis and follow-Up. Deveci MS, Deveci G, LiVolsi VA, Baloch ZW. Cytojournal. 2006 Apr 7;3:9. PMID: 16603062 [Free]
The role of fine-needle aspiration biopsy in the management of patients with thyroid nodules. Zagorianakou P, Malamou-Mitsi V, Zagorianakou N, Stefanou D, Tsatsoulis A, Agnantis NJ. In Vivo. 2005 May-Jun;19(3):605-9. PMID: 15875783 [Free]