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.

FNA diagnosis of poorly differentiated thyroid carcinoma. A review of the recent literature.

Poorly differentiated thyroid carcinoma (PDTC) is a follicular cell-derived tumour that was recognised as a distinct entity by the World Health Organisation in 2004. The natural history and pathological features of PDTC are reported to be intermediate between those of well-differentiated and undifferentiated (anaplastic) thyroid carcinomas. Preoperative identification of PDTC could facilitate better initial patient management in many cases, namely more extensive surgery, without any delay. However, according to some experts, a diagnosis of PDTC can only be rendered on histologic specimens based on criteria recommended in the Turin proposal. Although high-grade features (namely necrosis and mitoses) can be recognised in FNA material, other cytomorphological features have limited value for the preoperative diagnosis of PDTC and specific features for a definitive diagnosis of PDTC have not yet been clearly defined. Here, we review the current status and future prospects for cytological recognition of PDTC; we emphasise the features that should raise suspicion of this rare condition in FNA cytology and provide an update on molecular features and management of PDTC. Despite proposed histological criteria for the diagnosis of PDTC, its recognition on routine thyroid cytology presents a notable challenge. Current and future advances in molecular testing could contribute to the cytological diagnosis of PDTC.

Molecular imaging with (99m)Tc-MIBI and molecular testing for mutations in differentiating benign from malignant follicular neoplasm: a prospective comparison.

PURPOSE: To compare mutation analysis of cytology specimens and (99m)Tc-MIBI thyroid scintigraphy for differentiating benign from malignant thyroid nodules in patients with a cytological reading of follicular neoplasm. METHODS: Patients ≥18 years of age with a solitary hypofunctioning thyroid nodule (≥10 mm), normal thyrotropin and calcitonin levels, and a cytological diagnosis of follicular neoplasm were prospectively enrolled. Mutation analysis and (99m)Tc-MIBI scintigraphy were performed and patients were subsequently operated on to confirm or exclude a malignant lesion. Mutations for KRAS, HRAS and NRAS and for BRAF and translocations of PAX8/PPARγ, RET/PTC1 and RET/PTC3 were investigated. Static thyroid scintigraphic images were acquired 10 and 60 min after intravenous injection of 200 MBq of (99m)Tc-MIBI and visually assessed. Additionally, the MIBI washout index was calculated using a semiquantitative method. RESULTS: In our series, 26 % of nodules with a follicular pattern on cytology were malignant with a prevalence of follicular carcinomas. (99m)Tc-MIBI scintigraphy was found to be significantly more accurate (positive likelihood ratio 4.56 for visual assessment and 12.35 for semiquantitative assessment) than mutation analysis (positive likelihood ratio 1.74). A negative (99m)Tc-MIBI scan reliably excluded malignancy. CONCLUSION: In patients with a thyroid nodule cytologically diagnosed as a follicular proliferation, semiquantitative analysis of (99m)Tc-MIBI scintigraphy should be the preferred method for differentiating benign from malignant nodules. It is superior to molecular testing for the presence of differentiated thyroid cancer-associated mutations in fine-needle aspiration cytology sample material.

Laser capture microdissection is a valuable tool in the preoperative molecular screening of follicular lesions of the thyroid: an institutional experience.

OBJECTIVES: The application of molecular tests to thyroid fine needle aspiration (FNA) has been shown to be a valuable tool to better refine the pre-operative malignant risk of patients with indeterminate cytology results. In this study, we investigated the feasibility of using the laser capture microdissection (LCM) technique to obtain DNA and RNA for molecular tests in routine thyroid FNA smears. METHODS: Nine coupled FNA and histological retrospective cases and 31 prospective FNA cases with a follicular neoplasm/suspicious for a follicular neoplasm (FN/SFN) diagnosis were included in this study. Both cytological and histological specimens were investigated by direct sequencing and reverse transcription-polymerase chain reaction (RT-PCR) for BRAF and RAS mutations and for PAX8/PPARG and RET/PTC rearrangements, respectively. RESULTS: LCM yielded good DNA and RNA quality in all cases (100%) in both series, irrespective of the staining used (Giemsa, Papanicolaou, immunostain for thyroglobulin) and the cytology technique (conventional or liquid-based preparations). Total mutations found in the FNA and in the corresponding histological specimen in both series were: one PAX8/PPARG rearrangement in a follicular carcinoma (FC), four NRAS mutations [in two FCs, one papillary carcinoma and one follicular adenoma (FA)] and one HRAS mutation in one FA. The sensitivity was 67% and the specificity was 91%. CONCLUSIONS: LCM is a valuable tool to obtain good quality DNA and RNA for molecular tests in cytological material from thyroid FNA, and can be a useful option in the management of patients with an FN/SFN FNA diagnosis.

Cytologic features of focal papillary thyroid carcinoma arising within follicular adenoma: a masked cytomorphologic analysis of 17 cases.

BACKGROUND/OBJECTIVE: Focal papillary thyroid carcinoma (PTC) arising within a follicular adenoma (PTCFA) represents a clinically significant, but rare, histopathologic subset of papillary carcinomas whose cytologic features have not been well described. This uncommon presentation of PTC may contribute to a subset of thyroid aspirates interpreted as 'atypia of undetermined significance/follicular lesion of undetermined significance' (AUS/FLUS). STUDY DESIGN: Seventeen fine-needle aspiration biopsy (FNAB) cases diagnosed as 'PTCFA' on corresponding surgical excision were identified from the archival records of 2 large academic medical centers. A control group of 40 FNAB comprised of 20 follicular adenomas (FA) and 20 PTC was identified (based on the corresponding surgical pathology diagnosis) for comparison. All 57 FNAB were reviewed in a masked fashion and scored for a series of 31 cytomorphologic features. The intraclass correlation between diagnostic categories and overall agreement between cytopathologists was statistically evaluated. RESULTS: Aspirates of PTCFA were originally diagnosed as 'negative' (n = 3), 'AUS/FLUS' (n = 7), 'suspicious for a follicular neoplasm' (n = 3), 'suspicious for malignancy' (n = 3), and 'malignant' (n = 1). On masked review, the most common cytomorphologic features of PTCFA were a nonmacrofollicular cytoarchitectural pattern (71%), medium-large cell size (74%), and micronucleoli (79%). Intranuclear pseudoinclusions and a papillary architecture were absent in 85 and 88% of the cases, respectively. Relative to the 2 control groups, the PTCFA cases demonstrated overlapping features between FA and PTC for the majority of the 31 examined cytomorphologic features. CONCLUSION: PTCFA represent a rare subset of PTC that is difficult to recognize as PTC by FNAB. Most cases exhibit overlapping features between a benign thyroid nodule and conventional PTC, and they are often interpreted as 'AUS/FLUS'.

[Fine needle aspiration of the thyroid: the value of on-site evaluation]. / Ponction à l'aiguille fine de la thyroïde: intérêts de l'évaluation cytologique immediate.

Thyroid nodules are very common in the general population and most of them are benign. Fine needle aspiration (FNA) of the thyroid is routinely used because it is a rapid, simple, accurate and cost-effective technique which allows the adequate selection of patients who should be managed surgically. However, the diagnostic yield of FNA is variable and depends of multiple factors including the one who performs FNA, the aspiration and cytological slide preparation techniques, and cytopathologist's experience. On-site evaluation of thyroid FNA material and close clinico-pathological collaboration offer many advantages and optimizes the yield of FNA.

Natural history of SARS-CoV-2 infection in healthcare workers in Northern Italy.

At present, the time-frame used for the quarantine of individuals with coronavirus disease 2019 (COVID-19) is the entire duration of symptoms plus 14 days after symptom recovery; however, no data have been reported specifically for healthcare workers (HCWs). In the study population of 142 HCWs with COVID-19, the mean time for viral clearance was 31.8 days. Asymptomatic subjects cleared the virus more quickly than symptomatic subjects (22 vs 34.2 days; P<0.0001). The presence of fever at the time of diagnosis was associated with a longer time to viral clearance (relative risk 11.45, 95% confidence interval 8.66-14.25; P<0.0001). These findings may have a significant impact on healthcare strategies for the future management of the COVID-19 pandemic.

Diverse glandular pathologies coexist with high-grade squamous intraepithelial lesion in cyto-histological review of atypical glandular cells on ThinPrep specimens.

OBJECTIVE: To identify in cytology, high-grade squamous intraepithelial lesions with endocervical glandular extension in cases previously diagnosed as atypical glandular cells (AGC), analyse possible reasons for the diagnostic pitfall and document the frequency of glandular pathology coexisting with high-grade cervical intraepithelial lesion in histology. METHODS: Thirty-nine ThinPrep cervical smear (Pap) tests reported as AGC of undetermined significance and showing high-grade lesions on histology [cervical intraepithelial neoplasia (CIN) 2 or 3, endometrial or extrauterine adenocarcinoma] were reviewed retrospectively to identify the cases of high-grade squamous intraepithelial lesion with endocervical glandular extension, using the Bethesda 2001 system. Cyto-histological correlation was performed. RESULTS: A high frequency of diverse glandular pathologies coexisted with high-grade cervical intraepithelial lesions on histology. This included endocervical glandular extension in 63%, benign glandular pathology in 33% and pre-neoplastic or malignant glandular pathology (endocervical glandular dysplasia, adenocarcinoma in situ and metastatic breast carcinoma) in 17% cases. On cytology, the sensitivity was 40%, specificity was 80% and positive predictive value was 86% for endocervical gland extension in high-grade squamous intraepithelial lesions. CONCLUSIONS: Special efforts to recognize endocervical glandular extension in high-grade squamous intraepithelial lesions and glandular neoplasia coexisting with squamous intraepithelial lesions from the heterogeneous category of AGC can contribute to increasing the diagnostic accuracy. The identification of endocervical glandular extension on cervical cytology would alert the gynaecologist to perform a thorough assessment of the endocervix during colposcopy. This could also help to decide on the need to perform deeper conization rather than loop electrosurgical excision procedure to ensure negative margins when colposcopic biopsy shows CIN 2 or 3.

[Clinical isolates of Pseudomonas aeruginosa producers of extended spectrum beta-lactamases at a private institution in Cordoba]. / Aislados clínicos de Pseudomonas aeruginosa productores de beta-lactamasa de espectro extendido en un centro privado de Córdoba.

Extended spectrum beta-lactamases (ESBL) are capable of inhibiting the action of extended spectrum cephalosporins and monobactams. The objective of this work is to describe six isolates of ESBL producing Pseudomonas aeruginosa, retrieved from intensive care patients. The susceptibility test was performed by diffusion. For the phenotypic detection of ESBL, the following was assessed: the difference between ceftazidime ceftazidime/clavulanic acid (CAZ-CAC) and the synergy between imipenem-ceftazidime (IMI-CAZ) and cefepime-ceftazidime/clavulanic acid -ceftazidime (FEP-CAC-CAZ). The presence of metallo-beta-lactamases (MBL) was discarded through the double disc imipenem-EDTA/mercaptoacetic-meropenem (IMI-EDTA/SMA-MER) method. Molecular characterization of ESBL was performed by polymerase chain reaction (PCR) with blaGES primers. Synergy IMI-CAZ was observed in the studied strains; ESBL type GES was confirmed in five of them. The strategic location of the discs and the evaluation of alert signals for the detection of ESBL is essential, thus contributing to the correct recommendation of treatment in the clinical report.

Nabothian cyst content: A potential pitfall for the diagnosis of invasive cancer on Pap test cytology.

Nabothian cysts are common, benign findings of the squamocolumnar junction of the adult cervix. These cysts are filled with mucus and can also contain proteinaceous material, neutrophils, or neutrophil debris. Nabothian cysts can be broken by the spatula during smear taking, may stick to the brush and be smeared onto slides in conventional cytology or dissolved in the preserving solution for liquid-based cytology (LBC) preparations. The granular content of Nabothian cysts may be mistaken for the tumor diathesis (TD) pattern associated with invasive carcinoma. In the case described, the patient presented a high-grade squamous intraepithelial lesion associated with granular material (Nabothian cyst content) that we considered erroneously on LBC to be TD-like material, thus, raising the suspicion of invasive carcinoma. To the best of our knowledge, this is the first report showing that Nabothian cyst content may present a potential pitfall in the diagnosis of invasive carcinoma on LBC.