Management of thyroid cytological material, preanalytical procedures and bio-banking.

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.

Incidence, malignancy rates of diagnoses and cyto-histological correlations in the new Italian Reporting System for Thyroid Cytology: An institutional experience.

OBJECTIVE: FNA biopsy is considered as the most accurate method for the selection of patients with thyroid nodules that need for surgery or for the wait and see management. The aim of the present study is to clarify the risk of malignancy for the cytological data classified according to the 2014 Italian reporting system. METHODS: We report a retrospective analysis of 4043 patients in our institution's experience during the period April 2014 through December 2016 with the Italian reporting system for thyroid cytology. RESULTS: The diagnostic incidences of the 4043 cases were as follows: 9.8% TIR1; 1.3% TIR1C; 70% TIR2; 6.6% TIR3A; 4.5% TIR3B; 2.4% TIR4; 5.2% TIR5. A repeated aspiration was carried out in 68 out of 269 cases (25%) classified as TIR3A. A total of 407 cases with cytology underwent surgical resection. A malignant neoplasm was detected in 261 out of 407 (64%) cases. Regarding TIR3B, surgical excision was undertaken in 109 cases, which included 42 high-risk lesions and 67 Hürthle cell neoplasms. The risk of malignancy was significantly higher in the former compared to the latter (50% vs 9%; P<.05). CONCLUSIONS: This investigation emphasises the reliability of the 2014 Italian Reporting System concerning the mutual frequency of the diagnostic categories. The risk of malignancy is perfectly within the range of the estimated values.

The potential of liquid-based cytology in lymph node cytological evaluation: the role of morphology and the aid of ancillary techniques.

OBJECTIVES: Our aim was to evaluate the feasibility and diagnostic accuracy of liquid-based cytology (LBC) on lymph node fine needle aspiration (FNA). FNA may fulfil a challenging role in the evaluation of the majority of primary (benign and malignant) diagnoses as well as metastatic lymph node lesions. Although the morphological features may be quite easily recognized, cytological samples with a scant cellular component may raise some issues. METHODS: We appraised 263 cytological lymph nodes from different body regions analysed between January and December 2013, including 137 male and 126 female patients, and processed with LBC. RESULTS: The cytological diagnoses included 160 benign and 103 malignant lesions. We reported 35 benign and 73 malignant lesions from 108 with surgical follow-up. The latter malignant series included 68 metastatic lesions, four suspicious for malignancy and one inadequate sample. The cytological diagnoses were supported by 62 conclusive immunocytochemical and 28 molecular analyses. Of the 108 cases, we documented 35 true negatives, 72 true positives, one false negative and no false positives, resulting in 98.6% sensitivity, 100% specificity, 99% diagnostic accuracy, 97.2% negative predictive value and 100% positive predictive value. CONCLUSIONS: FNA represents the first diagnostic tool in lymph node management and a reliable approach in order to avoid an excision biopsy. Furthermore, LBC is a feasible method for ancillary tests for which methanol-fixed samples are suitable, such as immunocytochemistry and molecular analysis.

Large non-functioning parathyroid cysts: our institutional experience of a rare entity and a possible pitfall in thyroid cytology.

OBJECTIVE: Large non-functioning parathyroid cysts represent a rare entity with a benign clinical course. They may be misdiagnosed as thyroid cystic neoplasms on fine needle aspiration cytology (FNAC), resulting in inappropriate surgical treatment. We evaluated our institutional experience in the diagnosis of large parathyroid cystic lesions underlining all the differential diagnoses and pitfalls. METHODS: In the period between 1998 and 2012, we reported the cytology of eight large (>2.5 cm) parathyroid cystic lesions (all female patients) with histological control. The aspirations were performed with a 25-gauge needle with ultrasonographic guidance. The aspirated material was processed with liquid-based cytology (LBC). All the patients had normal serum parathyroid hormone (PTH) and calcium. RESULTS: The cytological samples showed a fluid watery component without colloid and few or absent epithelial cells. The resulting negativity for thyroglobulin and positivity for PTH, carried out on the cystic fluids, suggested parathyroid lesions rather than either thyroid cystic lesions (including follicular thyroid neoplasm) or cystic malignant lesions. All the patients underwent surgery without complications. CONCLUSIONS: To the best of our knowledge, this is one of the largest series with cytohistological evaluation of large parathyroid cysts. The incidence of large parathyroid cysts remains controversial as most patients are asymptomatic. FNAC may be performed with conclusive results in the majority of cystic cases. The detection of PTH and calcium on the cystic liquid is likely to achieve a correct cytological diagnosis, allowing adequate treatment and ruling out a more frequent thyroid lesion.

A systematic review and meta-analysis of CK20, CD44, Ki67 and p53 as immunohistochemical markers in bladder carcinoma in situ.

BACKGROUND: Urothelial dysplasia and carcinoma in situ (CIS) are related to recurrence and progression of urothelial carcinoma. Differentiating CIS and dysplasia from reactive atypia is often difficult based only on histological features. The integration of histological findings with immunohistochemistry is used in routine practice to make a diagnosis of CIS and, for this purpose, the immunohistochemical markers CK20, CD44, Ki67 and p53 are used to supplement histology. In this work, we aimed to assess CK20, CD44, Ki67 and p53 as immunohistochemical markers in patients with CIS through a systematic review and meta-analysis. MATERIALS AND METHODS: A systematic review was performed by searching electronic databases for English-language studies published from January 2010 to April 2021. Studies were considered eligible if they evaluated the CK20, CD44, Ki67 and p53 expression in CIS. RESULTS: In total, 15 references were suitable for quantitative review. The overall rate of CK20, CD44, Ki67 and p53 expression in CIS was 43%, 31%, 44%, 38%, respectively. CONCLUSIONS: Our study supports the 2014 International Society of Urologic Pathology consensus that histological assessment remains the gold standard to diagnose urothelial CIS and suggests that a very close correlation between morphological, immunohistochemical and clinical data is essential to provide the best management for patients with bladder carcinoma.