Publications by authors named "Michael S Landau"

Background: Some thyroid nodules cytologically presenting as follicular neoplasm, Hürthle cell (Oncocytic) type (FNHCT), are not oncocytic tumors and represent autonomously functioning thyroid nodules (AFTNs) with TSHR, GNAS, and EZH1 mutations or oncocytic metaplasia. A to be defined subset of FNHCT harbors genome haploidisation-type DNA copy number alterations (GH-CNA). Molecular profiling of FNHCT may distinguish oncocytic neoplasms from its mimics.

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Article Synopsis
  • Hürthle cell carcinoma (HCC) shows significant DNA copy number alterations (CNA) predominantly of genome haploidization type, with a notable occurrence in Hürthle cell adenomas (HCA), while being absent in Hürthle cell hyperplastic nodules (HCHN).* -
  • In a study analyzing FNA samples, 34% of nodules with CNA were found to be malignant, and the likelihood of cancer increased with the size of the nodules, especially in those with GH-type CNA.* -
  • Overall, the presence of CNA, combined with other genetic mutations and nodule size, provides valuable insights for predicting malignancy in thyroid nodules.*
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Background & Aims: The assessment of therapeutic response after neoadjuvant treatment and pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) has been an ongoing challenge. Several limitations have been encountered when employing current grading systems for residual tumor. Considering endoscopic ultrasound (EUS) represents a sensitive imaging technique for PDAC, differences in tumor size between preoperative EUS and postoperative pathology after neoadjuvant therapy were hypothesized to represent an improved marker of treatment response.

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Background: Acinic cell carcinoma (AcCC) is diagnostically challenging on fine-needle aspiration because it can mimic several other neoplasms or even normal acinar tissue. Immunopositivity for DOG1, especially circumferential membranous staining, can support the diagnosis of AcCC but is not entirely specific, and it is prone to technical and interpretive challenges on small specimens. NR4A3 (nuclear receptor subfamily 4 group A member 3) translocation and nuclear NR4A3 overexpression were recently described in the majority of AcCCs.

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Background: Molecular testing of thyroid nodules with indeterminate fine-needle aspiration (FNA) cytology is commonly used to guide patient management and is typically performed on freshly collected FNA samples. In this study, the authors evaluated the performance of the ThyroSeq test in cytology smear slides.

Methods: Air-dried Diff-Quik (DQ)-stained and alcohol-fixed Papanicolaou (Pap)-stained smears were used to determine required cellularity and sensitivity of mutation detection and to compare ThyroSeq v3 Genomic Classifier (GC) results obtained in cytology smears and fresh FNA samples from the same nodules.

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Mutations in RAS occur in 30-50% of metastatic colorectal carcinomas (mCRCs) and correlate with resistance to anti-EGFR therapy. Consequently, mCRC biomarker guidelines state RAS mutational testing should be performed when considering EGFR inhibitor treatment. However, a small subset of mCRCs are reported to harbor RAS amplification.

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Introduction: One of the key features of the Bethesda System for Reporting Thyroid Cytopathology is the risk of malignancy (ROM), which guides management for each diagnostic category. However, calculation of the ROM can be challenging for indeterminate diagnoses because only a portion of cases will be resected for cytologic-histologic correlation (CHC) analyses. In the present study, we used the probability of cancer information from ThyroSeq, version 3, reports to calculate the molecular-derived (MD) ROM for indeterminate categories.

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Introduction: At our institution, almost all thyroid fine-needle aspiration (FNA) procedures are performed by either Endocrinology or Radiology personnel. In this study, we compared the cytology and molecular adequacy rates of these 2 thyroid FNA practices, which differ on several aspects of specimen procurement.

Materials And Methods: All thyroid FNA specimens from Endocrinology and Radiology practices between September 2008 and December 2016 were included.

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Artificial intelligence (AI) has made impressive strides recently in interpreting complex images, thanks to improvements in deep learning techniques and increasing computational power. Researchers have started applying these advanced techniques to pathology images, although most efforts have been focused on histopathology. Cytopathology, however, remains the original field of pathology for which AI models for clinical use were successfully commercialized, to assist with automating Papanicolaou test screening.

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Background: The benign call rate (BCR) is the percentage of cytomorphologically indeterminate cases with subsequent benign or negative molecular results. For rule-out tests, the BCR is an important parameter because these molecular "negative" cases may be managed similarly to those with a benign cytology diagnosis. Although earlier versions of ThyroSeq molecular tests were less effective in excluding malignancy, the extensively expanded v3 version with a high negative predictive value is considered to represent a rule-out test.

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Background & Aims: It is important to identify superficial (T1) gastroesophageal adenocarcinomas (EAC) that are most or least likely to metastasize to lymph nodes, to select appropriate therapy. We aimed to develop a risk stratification model for metastasis of superficial EAC to lymph nodes using pathologic features of the primary tumor.

Methods: We collected pathology data from 210 patients with T1 EAC who underwent esophagectomy from 1996 through 2012 on factors associated with metastasis to lymph nodes (tumor size, grade, angiolymphatic invasion, and submucosal invasion).

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Reduced CDX2 and cytokeratin 20 (CK20) expression in colorectal carcinoma with BRAF mutation and high-level microsatellite instability (MSI-H) has been well documented. The immunophenotype of BRAF-mutated microsatellite stable (MSS) colorectal carcinoma has not been reported. We analyzed 205 colorectal carcinomas including 28 BRAF-mutated MSS, 53 BRAF-mutated MSI-H, and 124 BRAF wild-type MSS tumors for CDX2, cytokeratin 7 (CK7), and CK20 immunohistochemical expression.

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The treatment approach for superficial (stage T1) esophageal adenocarcinoma critically depends on the pre-operative assessment of metastatic risk. Part of that assessment involves evaluation of the primary tumor for pathologic characteristics known to predict nodal metastasis: depth of invasion (intramucosal vs submucosal), angiolymphatic invasion, tumor grade, and tumor size. Tumor budding is a histologic pattern that is associated with poor prognosis in early-stage colorectal adenocarcinoma and a predictor of nodal metastasis in T1 colorectal adenocarcinoma.

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Cells of the monocyte series respond to follicle stimulating hormone (FSH) by poorly characterized mechanisms. We studied FSH-receptors (FSH-R) and FSH response in nontransformed human monocytes and in osteoclasts differentiated from these cells. Western blot and PCR confirmed FSH-R expression on monocytes or osteoclasts, although at low levels relative to ovarian controls.

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