Clinicopathological features of papillary thyroid microcarcinoma with a diameter less than or equal to 5 mm.

PURPOSE: This retrospective study was conducted to assess the epidemiological, clinical and histologic characteristics of incidentally identified and presurgically diagnosed papillary thyroid microcarcinomas less than or equal to 5 mm in size (small PTMC). MATERIALS AND METHODS: Cases from October 2003 to February 2018 were retrieved from pathology databases, and their clinicopathological features were reviewed. RESULTS: There were a total of 182 cases of small PTMCs, 141 women and 41 men. The mean age at diagnosis was 53.5. Most of the small PTMCs were not detected on clinical examination and workup and were diagnosed incidentally during pathologic examination. 21.4% of small PTMCs showed multifocality, with 21 cases of unilateral multifocal lesions and 18 cases with bilateral multifocal tumors. Small PTMCs were most often follicular variant (51.9%) followed by classic type (47.5%). The average size of follicular variants appeared to be larger than that of the classic type PTMCs (2.84 ±â€¯1.43 mm vs 2.26 ±â€¯1.51 mm, P = 0.01). A total of 66 cases (36.3%) had regional lymph node sampling or selective neck dissection and 15 of these cases identified lymph node metastasis (22.7%). 46.7% of patients with node positive microcarcinomas were male compared with 16% male in group with negative lymph nodes (P = 0.03). CONCLUSIONS: Small PTMCs (≤5 mm) are often multifocal and bilateral and histology is commonly both the classical and follicular variant of PTC. While often diagnosed incidentally small PTMC can lead to regional lymph node involvement in a significant portion of cases and evaluation of the regional lymph nodes should be considered in the clinical management of these patients.

Supernatant fluid from endobronchial ultrasound-guided transbronchial needle aspiration for rapid next-generation sequencing.

INTRODUCTION: There is an increasing demand to optimize the workflow and maximize tissue available for next-generation sequencing (NGS) for non-small cell carcinoma. We looked at transbronchial needle endobronchial ultrasound-guided bronchoscopy with transbronchial needle aspiration samples and evaluated the performance of supernatant (SN) fluid processed from a dedicated aspirate collected for NGS testing. MATERIALS AND METHODS: Nineteen samples were collected and processed using a new workflow. Five aspirates were collected in formalin. One additional dedicated pass was collected fresh and centrifuged. The resulting cell pellet was added to formalin for cell block (CB) processing. DNA and RNA were extracted from concentrated SN for targeted testing using the Oncomine Precision Assay (Thermo Scientific, Waltham, MA). NGS results from the corresponding CB samples were used as "controls" for comparison. RESULTS: Thirty-one mutations were detected in SN (Table 1). The most frequently mutated genes were TP53 (35%), EGFR (23%), KRAS (13%), CTNNB1 (6%), and ERBB2 (6%). There was 100% concordance between the mutations detected in SN and corresponding CBs with comparable variant allele frequencies. Turnaround time of NGS results was 1 day for SN compared to 4-10 days for CB. CONCLUSIONS: We were able to demonstrate the usefulness of SN for reliable rapid molecular results. We successfully incorporated the workflow for tissue handling and processing among our clinical, cytopathology, and molecular teams. Molecular results were available at the same time as the cytologic diagnosis, allowing for timely reporting of a comprehensive diagnosis. This approach is particularly useful in patients with advanced disease requiring urgent management.