Management of thyroid cytological material, preanalytical procedures and bio‐banking

Abstract

Thyroid nodules are common and are increasingly detected due to recent advances in imaging techniques. However, clinically relevant thyroid cancer is rare and the mortality from aggressive thyroid cancer remains constant. Fine needle aspiration cytology (FNAC) is a standard method for diagnosing thyroid malignancy and the discrimination of malignant nodules from goitre. As the examined nodules on thyroid FNAC are often small incidental findings, it is important to maintain a low rate of undetermined diagnoses requiring further clinical work up or surgery. The most important factors determining the accuracy of the cytological diagnosis and suitability for biobanking of thyroid FNACs are the quality of the sample and availability of adequate tissue for auxiliary studies. This article discusses technical aspects (preanalytics) of performing thyroid FNAC, including image guidance and rapid on-site evaluation, sample collection methods (conventional slides, liquid-based methods, cell blocks) and storage (bio-banking). The spectrum of special studies (immunocytochemistry on direct slides or liquid-based cytology, immunohistochemistry on cell blocks and molecular methods) required for improving the precision of the cytological diagnosis of the thyroid nodules is also discussed.

Management of cytological material for ancillary studies: Still an issue one decade later?

“…In this issue of Cytopathology , several papers address the management of cytological material, preanalytical procedures and biobanking in thyroid, lymph node and effusion cytology . Despite great advances in the standardisation of the many variables affecting the preanalytical phase over the last decade, this remains an issue when we use cytological material for ancillary studies.…”

“…Despite great advances in the standardisation of the many variables affecting the preanalytical phase over the last decade, this remains an issue when we use cytological material for ancillary studies. Not only do different types of cytological preparations (smears, liquid‐based cytology, cell‐blocks) affect the management of cytological material for further studies, the vials and devices used, quantity and quality of the material obtained, the type of pathology studied and the ancillary technique that will be applied can all influence the success of the test . Specimen acquisition is the first step in obtaining a good and adequate samples and the articles published in this issue review the technical aspects of the interventional cytology .…”

“…Not only do different types of cytological preparations (smears, liquid‐based cytology, cell‐blocks) affect the management of cytological material for further studies, the vials and devices used, quantity and quality of the material obtained, the type of pathology studied and the ancillary technique that will be applied can all influence the success of the test . Specimen acquisition is the first step in obtaining a good and adequate samples and the articles published in this issue review the technical aspects of the interventional cytology . Clear communication between the clinicians, cytotechnicians and pathologists, use of image‐guide procedures and optimisation of the technique for best diagnostic yield are simple but fundamental aspects to obtain good quality material.…”

“…During ROSE, we can decide if additional passes are needed in anticipation of ancillary studies and it is possible to prioritise the type of cytological specimen (smears, suspensions or cell blocks) according the preference and experience of the laboratory. However, as discussed in one of the reviews, even in lung cancer studies there is continued debate about the efficacy of ROSE in endobronchial ultrasound‐guided needle aspiration . It seems to me that ROSE can be extremely useful in some type of cytology, such as lymph node aspirates, while in others, such as thyroid aspiration, its benefit is limited …”

“…However, as discussed in one of the reviews, even in lung cancer studies there is continued debate about the efficacy of ROSE in endobronchial ultrasound‐guided needle aspiration . It seems to me that ROSE can be extremely useful in some type of cytology, such as lymph node aspirates, while in others, such as thyroid aspiration, its benefit is limited …”