1033 Endobronchial Sclerotic Neurofibroma: A Case Report of a Very Rare Benign Tumour

Introduction Endobronchial neurofibromas are exceedingly rare benign lesions most commonly originating at the trachea. Primary pulmonary tumours of neurogenic origin such as peripheral nerve sheath tumours (PNSTs) are extremely rare, accounting for less than 0.2% of all lung tumours. Intrathoracic PNSTs are usually benign and are commonly found in the posterior mediastinum as schwannomas with female preponderance. We present the first reported occurrence of the sclerotic variant of endobronchial neurofibroma and the approach used in its definitive investigation and management. Case Report A 69-year-old Caucasian male with a 66 pack-year smoking history and a background of alcohol induced liver cirrhosis, peripheral vascular disease and dilated cardiomyopathy presented with dyspnoea and fatigue with severe normocytic anaemia. Computed Tomography (CT) chest, abdomen and pelvis revealed an indeterminate nodule at the secondary carina projecting into the bronchus intermedius (BI). Fibreoptic bronchoscopy showed a polypoid lesion with a vascular appearance. Under general anaesthetic, combined fibreoptic and rigid bronchoscopy was used to remove the lesion with rigid forceps. Gross histological appearance showed an 8x6x5mm pedunculated lesion with a 2mm diameter short stalk and histology of a sclerotic neurofibroma with fibroblasts and collagen, positively staining for S100 and LP10. This patient is due for follow up in 6-month with a CT chest to ensure no tumour recurrence. Conclusions Endobronchial neurofibromas appear highly vascular and demand extra caution at bronchoscopic intervention. Prompt, experienced thoracic surgical and intervention pulmonology input should always be sought. Combined approach of fibreoptic and rigid bronchoscopy allows better control of potential bleeding and the airway.

MON-511 Are Thyroid Nodule Fine Needle Aspiration Washings an Acceptable Alternative to Dedicated Fine Needle Aspirates When Obtaining Tissue Samples for Genetic Expression Classifier Analysis?

The Bethesda System for Reporting Thyroid Cytopathology stratifies thyroid nodules by risk associations. Approximately 15-30% of fine needle aspirations (FNA) fall into an indeterminate criteria, and two thirds are found to be surgically benign leading to unnecessary surgeries (1). Veracyte Inc. developed the Afirma gene expression classifier (GEC) to identify whether an indeterminate nodule had benign expression, with a NPV of 95% for AUS/FLUS (Atypia of undetermined significance/ follicular lesion of undetermined significance) nodules making it an excellent way to rule out malignancy (2). The goal of testing for thyroid cytology includes avoiding unnecessary surgery in benign nodules and identifying high risk from low risk lesions. The Afirma validation landmark study aided in the commercial approval for use in clinical practice after showing a 95.1% sample sufficiency when 2 dedicated samples were obtained in addition to the 3-5 FNA samples for cytology, but our institutional practice habits may suggest other techniques may be valid as well (2). We aimed to assess the rate of sufficient sample for GEC based on FNA washings at our institution, without using dedicated FNA for GEC. Data was gathered from all indeterminate nodule FNA washings referred for Afirma GEC from January 2015 through December 2017. Samples were determined on Afirma report as benign, suspicious, or insufficient and rate of insufficiency was determined. 95 indeterminate nodule FNA washings were sent for Afirma GEC. 93 (97.9%) samples were sufficient for RNA, with 47 (49.5%) reported as suspicious and 46 (48.4%) reported as benign, 2 (2.1%) samples were insufficient for RNA. 97.9% of our samples were sufficient when using FNA washings alone. Our experience suggests that the technique used at our clinical practice is an acceptable alternative to using an additional 2 passes for dedicated samples in collecting RNA for Afirma GEC. This method decreases need for call back for a second biopsy, is less time consuming, and potentially more cost effective. Limitations in our study are a small sample size limited to a single institution, differing number of FNA washings per total passes among practitioners, and variability of experience between providers. In conclusion thyroid nodule FNA washings are an acceptable alternative to dedicated FNA when obtaining tissue samples for genetic expression classifier analysis. Further studies with a larger sample size across different institutions are necessary. 1.Prathima S, Thyroid Research and Practice, January-April 2016; Vol 13: Issue 1; p 9-14 Yang SE et al, Cancer Cytopathology, February 2016, p 100-109 2. Alexander EK. Kennedy GC. Baloch ZW.et al. Preoperative diagnosis of benign thyroid nodules with indeterminate cytology. N Engl J Med. 2012;367(8):705–715.

Follicular neoplasm of the thyroid: can clinical, ultrasonographical and cytological factors be used to predict carcinoma and determine extent of surgery

Background: The optimal management of cytologically indeterminate thyroid nodules in follicular neoplasm is controversial. We examined the prevalence of malignancy within cytologically indeterminate follicular thyroid lesions in an attempt to predict malignancy based on clinical, sonographic and cytologic features.Methods: Retrospective study was done in between April 2017 to July 2019 of 46 patients having a diagnosis of follicular neoplasm on fine needle aspiration cytology.Results: A total of 46 patients (8 men, 38 women; mean age 47 year) with indeterminate cytology underwent thyroidectomy and had histopathological diagnoses. The prevalence of malignancy in patients was 34.7%. The size of nodules and ultrasonographic feature were significant predictor of malignancy with p value <0.05.Conclusions: Author can predict malignancy in follicular neoplasm of thyroid with indeterminate nodule by using clinical and sonographic feature for the best compromise between the risk of missing carcinomas and the need for reducing unnecessary surgical procedures and cost benefit of the patients.

A Monocentric Retrospective Study about the Correlation between Histology and Cytology of Thyroid Indeterminate Nodules Classified as TIR 3A and TIR 3B, according to 2014 Italian Consensus for Classification and Reporting of Thyroid Cytology

Background. In 2014, the Italian Consensus for Classification and Reporting of Thyroid Cytology (ICCRTC) reviewed the previous cytological classification proposed in 2007 including the subdivision of TIR 3 category into low risk (TIR 3A) and high risk (TIR 3B). In Italian literature, different rates of malignancy have been correlated to these subcategories. Objectives. The aim of the study is to present our experience on this subclassification for the assessment of the malignancy risk of indeterminate thyroid nodules. We correlated the subdivision into TIR 3A and TIR 3B with the histological report by highlighting the rates of malignancy detected in the two subcategories. On the one hand, we aimed to check if the groups are associated with a real and significant difference risk of malignancy. On the other hand, we evaluated the use of this subdivision in the choice of the appropriate treatment. Study Design. This is a retrospective review of all the patients with an indeterminate nodule who underwent US-FNA and had surgery at ASL Città di Torino between January 2005 and May 2018. Results. 150 patients have been analyzed for the research; 62 (41.3%) had a malignant histological report. Rates of malignancy between TIR 3A (20.8%) and TIR 3B (60.3%) were significantly different (p<0.0001). The subclassification had high sensitivity (75.8%; CI 63.3–85.8%) and NPV (79.3%; CI 68–87.8%) and low specificity (64.8%; CI 53.9–74.7%) and PPV (60.3; CI 48.5–71.2%). The measurement of the accuracy (AUC = 0.7) classified the test as “moderately accurate.” Conclusions. Obtained data show a great rate of false negative (20.8%) and limited AUC (0.7). According to our logistic regression, we argue that the 2014 subclassification into TIR 3A and TIR 3B should be considered for the choice of patient treatment, but at the same time, we believe that the association with other screening tests is necessary to increase the accuracy in the future.

Genetic testing for indeterminate thyroid cytology: review and meta-analysis

Thyroid cancer is the most frequent endocrine malignancy, and its incidence is increasing. A current limitation of cytological evaluation of thyroid nodules is that 20–25% are reported as indeterminate. Therefore, an important challenge for clinicians is to determine whether an indeterminate nodule is malignant, and should undergo surgery, or benign, and should be recommended to follow-up. The emergence of precision medicine has offered a valuable solution for this problem, with four tests currently available for the molecular diagnosis of indeterminate cytologies. However, efforts to critically analyze the quality of the accumulated evidence are scarce. This systematic review and meta-analysis is aimed to contribute to a better knowledge about the four available molecular tests, their technical characteristics, clinical performance, and ultimately to help clinicians to make better decisions to provide the best care options possible. For this purpose, we address three critical topics: (i) the proper theoretical accuracy, considering the intended clinical use of the test (rule-in vs rule-out) and the impact on clinical decisions; (ii) the quality of the evidence reported for each test (iii) and how accurate and effective have the tests proved to be after their clinical use. Together with the upcoming evidence, this work provides significant and useful information for healthcare system decision-makers to consider the use of molecular testing as a public health need, avoiding unnecessary surgical risks and costs.