EWSR1 translocation in primary hyalinising clear cell carcinoma of the thymus.

Aims: In thymic carcinomas, focal clear cell change is a frequent finding. In addition to a prominent, diffuse clear cell morphology, some of these carcinomas show an exuberant hyalinised extracellular matrix, and therefore probably represent a separate entity. However, a characteristic genomic alteration remains elusive.

Interobserver Variability in the Histopathologic Assessment of Extrathyroidal Extension of Well Differentiated Thyroid Carcinoma Supports the New American Joint Committee on Cancer Eighth Edition Criteria for Tumor Staging.

Extrathyroidal extension (ETE) by papillary and follicular thyroid carcinoma can be associated with increased risk of tumor recurrence and mortality. In the seventh edition of its Cancer Staging Manual, the American Joint Committee on Cancer (AJCC) defined minimal ETE as the involvement of skeletal muscle (i.e.

Solid Papillary Breast Carcinomas Resembling the Tall Cell Variant of Papillary Thyroid Neoplasms: A Unique Invasive Tumor With Indolent Behavior.

Thirteen cases of invasive solid papillary breast carcinomas resembling the tall cell variant of papillary thyroid neoplasms (BPTC) are reported here. Some cases had long-term follow-up. BPTC is a special type of primary breast neoplasm showing a triple-negative profile but low aggressive potential.

Distinctive Histogenesis and Immunological Microenvironment Based on Transcriptional Profiles of Follicular Dendritic Cell Sarcomas.

Follicular dendritic cell (FDC) sarcomas are rare mesenchymal tumors with variable clinical, morphologic, and phenotypic characteristics. Transcriptome analysis was performed on multiple FDC sarcomas and compared with other mesenchymal tumors, microdissected Castleman FDCs, and normal fibroblasts. Using unsupervised analysis, FDC sarcomas clustered with microdissected FDCs, distinct from other mesenchymal tumors and fibroblasts.

Primary Cerebellar Neuroendocrine Tumors: Chimeras or Real Entities? A Case Report with a 6-Year Follow-Up.

We report the case of a 38-year-old patient who was diagnosed with a cerebellar well-differentiated neuroendocrine tumor (WDNET) in 2009. At first glance, we believed that it was a metastasis from an unrecognized WDNET arising outside the cerebellum. However, despite a prolonged follow-up of 6 years, an extracranial WDNET has never been found.

Inter-Observer Variation in the Pathologic Identification of Extranodal Extension in Nodal Metastasis from Papillary Thyroid Carcinoma.

Background: Extranodal extension (ENE) in lymph node metastases has been shown to worsen the prognosis of papillary thyroid cancer (PTC). Despite the clinical significance of ENE, there are no stringent criteria for its microscopic diagnosis, and its identification is subject to inter-observer variability. The objective of this study was to determine the level of agreement among expert pathologists in the identification of ENE in PTC cases.

Inter-Observer Variation in the Pathologic Identification of Minimal Extrathyroidal Extension in Papillary Thyroid Carcinoma.

Background: Extrathyroidal extension (ETE) is a significant prognostic factor in papillary thyroid carcinoma (PTC). Minimal extrathyroidal extension (mETE) is characterized by involvement of the sternothyroid muscle or perithyroid soft tissue, and is generally identified by light microscope examination. Patients with mETE, identified pathologically, are automatically upstaged to pT3.

Uniform Labeling of Blocks and Slides in Surgical Pathology: Guideline From the College of American Pathologists Pathology and Laboratory Quality Center and the National Society for Histotechnology.

Context: The labeling of paraffin blocks and microscopic glass slides in the practice of surgical pathology varies from institution to institution and introduces potential risk of preanalytic error. Currently there are no evidence-based guidelines regarding the uniform labeling of these materials.

Objective: To develop recommendations that will address the need for adequate patient identification and provide a consistent method of identifying slides originating from a particular block.

Desmoplastic small round cell tumor 20 years after its discovery.

Desmoplastic small round cell tumor (DSRCT) was proposed as a distinct disease entity by William L Gerald and Juan Rosai in 1991. Over 850 patients have been reported in the medical literature. A specific translocation, t(11;22)(p13;q12), is seen in almost all cases, juxtaposing the EWS gene to the WT1 tumor suppressor gene.

Machine learning from concept to clinic: reliable detection of BRAF V600E DNA mutations in thyroid nodules using high-dimensional RNA expression data.

The promise of personalized medicine will require rigorously validated molecular diagnostics developed on minimally invasive, clinically relevant samples. Measurement of DNA mutations is increasingly common in clinical settings but only higher-prevalence mutations are cost-effective. Patients with rare variants are at best ignored or, at worst, misdiagnosed.

Multifocal fibrosing thyroiditis: report of 55 cases of a poorly recognized entity.

During the course of our consultation activity, we have recognized a peculiar form of thyroiditis in which multiple foci of fibrosis, most of which were associated with reactive atypia of the surrounding follicles, are present. We have referred to this condition, both in our consultation reports and in the third series of A.F.

Tall cell variant of papillary thyroid carcinoma in children: report of three cases with long-term follow-up from a single institution.

Papillary thyroid carcinoma (PTC), tall cell (TC) variant, is exceptional in children. In adults it represents about 20% of PTCs, featuring a high-risk neoplasm, with a 4-fold risk of relapse and a 20-fold relapse-related risk of death. Out of 42 cases of pediatric PTCs, we found 3 cases of PTC-TC (7%) with clinical data at onset and follow-up up to June 2014.

ITMIG consensus statement on the use of the WHO histological classification of thymoma and thymic carcinoma: refined definitions, histological criteria, and reporting.

Introduction: The 2004 version of the World Health Organization classification subdivides thymic epithelial tumors into A, AB, B1, B2, and B3 (and rare other) thymomas and thymic carcinomas (TC). Due to a morphological continuum between some thymoma subtypes and some morphological overlap between thymomas and TC, a variable proportion of cases may pose problems in classification, contributing to the poor interobserver reproducibility in some studies.

Methods: To overcome this problem, hematoxylin-eosin-stained and immunohistochemically processed sections of prototypic, "borderland," and "combined" thymomas and TC (n = 72) were studied by 18 pathologists at an international consensus slide workshop supported by the International Thymic Malignancy Interest Group.

Involvement of the testis and related structures by Rosai-Dorfman disease: report of 2 new cases and review of the literature.

This report describes 2 new cases of testicular involvement by Rosai-Dorfman disease, also known as sinus histiocytosis with massive lymphadenopathy, and reviews the clinical and pathologic features of the other cases documented in the literature (4 cases) or included in the sinus histiocytosis with massive lymphadenopathy registry (7 cases). Our patients were 42 and 68 years of age, respectively, reflecting the usual middle-age of all the previously reported cases in this location, except for 1, which occurred in a child. Five cases were bilateral, and other sites, such as lymph nodes, kidney, skin, and adrenal gland, were involved in 8 cases.

A prospective assessment defining the limitations of thyroid nodule pathologic evaluation.

Background: Clinical management of thyroid neoplasms is based on light microscopic diagnosis, but its accuracy and precision are poorly defined.

Objective: To assess inter- and intraobserver variability of preoperative cytopathologic and postoperative histopathologic thyroid diagnoses.

Design: Samples were collected in a prospective, multicenter trial validating a gene expression classifier between June 2009 and December 2010.

Does addition of BRAF V600E mutation testing modify sensitivity or specificity of the Afirma Gene Expression Classifier in cytologically indeterminate thyroid nodules?

Objective: The purpose of this study was to determine the frequency of BRAF mutation in cytologically indeterminate thyroid nodules and to investigate whether adding the BRAF test improves diagnostic accuracy of the Afirma Gene Expression Classifier (GEC).

Design: BRAF V600E mutational status was determined for DNA extracted from cytologically benign (n = 40), indeterminate (n = 208), and malignant (n = 48) fine-needle aspiration specimens previously categorized by GEC as molecularly Benign or Suspicious. Analytical performance of the BRAF assay was assessed to establish reproducibility and limits of detection.

Multifocal capillary hemangioma-like vascular proliferation of the kidney associated with clear cell renal cell carcinoma: a case report and review of the literature.

We report the case of a 69-year-old man who underwent a radical left nephrectomy for a renal mass. Microscopically, the features were those of a clear cell-type renal cell carcinoma associated with 2 foci of capillary hemangioma-like vascular proliferation in the adjacent renal parenchyma. The main differential diagnosis and the possible pathogenesis of this vascular lesion are discussed.

Papillary thyroid microcarcinoma with fatal outcome: evidence of tumor progression in lymph node metastases: report of 3 cases, with morphological and molecular analysis.

Papillary thyroid microcarcinoma generally carries an excellent prognosis, and fatal cases are becoming increasingly rare. Their pathologic and molecular features, however, remain largely unknown. We describe 3 cases of papillary thyroid microcarcinoma that, despite surgical and radioiodine treatment, recurred, metastasized, and eventually caused the death of the patients.

Clinicopathologic features and long-term outcomes of NUT midline carcinoma.

Purpose: NUT midline carcinoma (NMC) is a poorly differentiated squamous cancer characterized by rearrangement of the NUT gene. Research advances have provided opportunities for targeted therapy in NMC, yet the clinical features of this rare disease have not been systematically characterized. We report on a large population of such patients to identify the disease characteristics and treatments, correlate them with outcome, and to consider clinical recommendations.