Adequacy of the specimen

Specimens may be unsatisfactory due to obscuring blood, overly thick smears, air-drying of alcohol-fixed smears or an inadequate number of follicular cells.
Specimens containing at least five groups of follicular cells, each composed of at least ten cells, are considered satisfactory for evaluation.

With experience, the average “unsatisfactory” rate is about 5% to 10%. It is incorrect to consider unsatisfactory or non diagnostic tests as negative. The lowest unsatisfactory rate will be achieved by close cooperation between the clinician and the cytopathologist, with immediate assessment of material.

A follicle lined by bland thyrocytes. At least 5 such groups should be identified.	A larger group comprising 3-4 normal follicles.

The result of an FNA with a 25G needle on a benign thyroid nodule. Note the very small central haemorrhage.	Inadequate smear (blood).