Nomenclature Of Tumors Research Articles

PIT-1/SF-1 co-expression in pituitary neuroendocrine tumors (PitNETs) with comprehensive review of the literature: How should we best characterize these neoplasms?

The nomenclature and classification of neuroendocrine tumors of the anterior pituitary have undergone significant change over the last few years. Despite the updated classification system as devised by the World Health Organization, some tumors do not fit neatly into the currently defined categories. The most common tumor type not defined by the updated guidelines is a pituitary neuroendocrine tumor with co-expression of SF-1 and PIT-1. In this manuscript, we provide our institutional experience with such unusual cases and combine our findings with those in the available literature to provide the largest, most comprehensive dataset regarding clinical and pathologic information for these unique tumors. Based on our findings, we also propose a classification scheme for pituitary neuroendocrine tumors to integrate lineage, hormonal expression, and clinical function as we believe this constellation of information will best help the clinical teams treating these patients.

Revised Classification of Inner Ear Schwannomas.

Over the past two decades, there has been increasing interest in the diagnosis and management of schwannomas of the inner ear including hearing rehabilitation with cochlear implants. However, tumor nomenclature and classification within the literature have been variable and oftentimes cumbersome. The term "intralabyrinthine schwannoma" is in common use when describing these tumors but is a potential source of confusion given that people often use the term "labyrinth" or "labyrinthine" to refer to the vestibular component of the inner ear only (i.e., labyrinthectomy or the translabyrinthine approach).During the Ninth Quadrennial Conference on Vestibular Schwannoma and Other Cerebellopontine Angle Lesions in Bergen, Norway, in May 2023, a multidisciplinary group of conference participants met and discussed issues pertaining to current terminology and classifications to enhance clarity and to reflect recent advances in tumor management and hearing rehabilitation.Although a variety of terms have been previously used to describe inner ear schwannomas, consensus was achieved on the term "inner ear schwannoma (IES)" to describe eighth nerve schwannomas of the cochlea, vestibule, or semicircular canals. Subgroups under this term comprise intravestibular, intracochlear, or intravestibulocochlear inner ear schwannomas (low complexity tumors), inner ear schwannomas with transfundal extension into the internal auditory canal but without modiolar involvement (intermediate complexity tumors), and inner ear schwannomas with transfundal extension with modiolar involvement (high complexity tumors).The details of the recommendations for an updated and simplified tumor nomenclature centered around tumor control and hearing rehabilitation with cochlear implantation are presented.

Malignant Rhabdoid Tumor and Related Pediatric Tumors: Multimodality Imaging Review with Pathologic Correlation.

Malignant rhabdoid tumors (MRTs) are rare but lethal solid neoplasms that overwhelmingly affect infants and young children. While the central nervous system is the most common site of occurrence, tumors can develop at other sites, including the kidneys and soft tissues throughout the body. The anatomic site of involvement dictates tumor nomenclature and nosology. While the clinical and imaging manifestations of MRTs and other more common entities may overlap, there are some site-specific distinctive imaging characteristics. Irrespective of the site of occurrence, somatic and germline mutations in SMARCB1, and rarely in SMARCA4, underlie the entire spectrum of rhabdoid tumors. MRTs have a simple and remarkably stable genome but can demonstrate considerable molecular and biologic heterogeneity. Related neoplasms encompass an expanding category of phenotypically dissimilar (nonrhabdoid tumors driven by SMARC-related alterations) entities. US, CT, MRI, and fluorodeoxyglucose PET/CT or PET/MRI facilitate diagnosis, initial staging, and follow-up, thus informing therapeutic decision making. Multifocal synchronous or metachronous rhabdoid tumors occur predominantly in the context of underlying rhabdoid tumor predisposition syndromes (RTPSs). These autosomal dominant disorders are driven in most cases by pathogenic variants in SMARCB1 (RTPS type 1) and rarely by pathogenic variants in SMARCA4 (RTPS type 2). Genetic testing and counseling are imperative in RTPS. Guidelines for imaging surveillance in cases of RTPS are based on age at diagnosis. ©RSNA, 2024 Supplemental material is available for this article.

Does New WHO 2022 Nomenclature of Pituitary Neuroendocrine Tumors Offer an Extra Edge to the Neurosurgeons for Its Management? A Narrative Review.

The new World Health Organization nomenclature of pituitary tumors was introduced in the year 2022 after much deliberation. This nomenclature clearly demarcates the anterior lobe (adenohypophyseal), posterior lobe (neurohypophyseal), and hypothalamic tumors. There is also focus on other tumors arising in the sellar region. The nomenclature has also advocated the routine use of immunohistochemistry in describing the pituitary transcription factors that plays a fundamental role in distinguishing the cell lineage of these tumors. However, the nomenclature is complex in understanding due to inclusion of pathological correlates like transcription factors, hormones, biomarkers, and various controversies that have emerged regarding the renaming of pituitary adenomas (PA) as PiTNETs ("Pituitary Neuroendocrine tumors") because majority of the adenomas are benign and have rare metastatic behavior while classifying them as PiTNETs will create unnecessary misinterpretation of these as aggressive tumors that will lead to apprehension among the patients. The new classification gives deeper insight into the histological picture of the various pituitary tumors but other than contributing to the follow-up strategy and postsurgery management, this classification does not add anything new that could be advantageous for the neurosurgeons in clinical practice and decision making, especially in deciding the plan of action for surgery. Hence, there is need of a more comprehensive, integrated, neuroradiological-based classification with more emphasis on the invasiveness of these tumors that would assist the neurosurgeons in planning the treatment strategy and managing patients of pituitary tumors.

Molecular profiling across histologies in lung cancer: Time to change WHO nomenclature?

8532 Background: Biomarker testing is essential for optimal therapeutic management of Non-Small lung Cancer (NSCLC). However, a not negligible percentage of patients (pts) is not tested in clinical practice for all the relevant actionable biomarkers. Biomarker testing is recommended in lung adenocarcinoma (LUAD), while in tumors with other histologies it is reserved when clinical features indicate a higher probability of an oncogenic driver. Histopathology report and biomarker testing are usually performed sequentially, which is time consuming and delays patient care. Herein we determined the distribution of actionable biomarkers across NSCLC histotypes and other clinic-demographic characteristics. Methods: This is an observational retrospective analysis on histologically confirmed NSCLC cases tested between 2014-2022 using FoundationOne/FoundationOneCDx assay. Histopathologies of all cases were centrally reviewed and confirmed by Board Certified Anatomic Pathologists. Results: 82,328 NSCLC pts were included. Actionable genomic alterations (GA) were found in 35.1% of the cases (Table). LUAD and adenosquamous (ASC) were more commonly associated with actionable GA (45.8% and 40.9%, respectively) as compared with sarcomatoid (29.1%), not otherwise specified (NOS) (27.6%), large cell (LCC) (21.1%), and squamous cell (LUSC) (6.5%) histologies. Sarcomatoid histology had the highest METex14 skipping mutations (muts) frequency (9.9% vs. 2.4% in LUAD). Tumor mutational burden (TMB) ≥10 Mut/Mb was associated with histology (50.9% in LCC, 40.8% in NOS, 39.1% in LUSC, and 36.3% in sarcomatoid vs. 31.2% in LUAD and 29.2% in ASC). Pts with actionable GA usually had a low TMB (80.9%). A significant correlation (p<0.005) between age and actionable GA was reported for BRAF/ ERBB2 muts, ALK/RET/ROS1 rearrangements (RE), and MET amplification. EGFR actionable muts and KRASG12C were more commonly observed in females, whereas no significant correlation between sex and other GA was observed. Finally, genetic ancestry analyses revealed a strong correlation between EGFR actionable muts and South/East Asian and American ancestries, but not for other GA. Conclusions: This is the largest NSCLC dataset analyzed for biomarker distribution across histologies, age, sex and genetic ancestry. This dataset confirms sufficient enough biomarker prevalence across LUAD and ASC carcinoma to be included in WHO nomenclature for lung tumors, and provides reassurance that cases with NOS, LCC and sarcomatoid histologies must be considered for biomarker workup. [Table: see text]

Pediatric CNS tumors and 2021 WHO classification: what do oncologists need from pathologists?

The fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS), published in 2021, established new approaches to both CNS tumor nomenclature and grading, emphasizing the importance of integrated diagnoses and layered reports. This edition increased the role of molecular diagnostics in CNS tumor classification while still relying on other established approaches such as histology and immunohistochemistry. Moreover, it introduced new tumor types and subtypes based on novel diagnostic technologies such as DNA methylome profiling. Over the past decade, molecular techniques identified numerous key genetic alterations in CSN tumors, with important implications regarding the understanding of pathogenesis but also for prognosis and the development and application of effective molecularly targeted therapies. This review summarizes the major changes in the 2021 fifth edition classification of pediatric CNS tumors, highlighting for each entity the molecular alterations and other information that are relevant for diagnostic, prognostic, or therapeutic purposes and that patients' and oncologists' need from a pathology report.

Critical appraisal of the WHO 2022 classification of thyroid cancer

ABSTRACT The WHO Classification of Endocrine and Neuroendocrine Tumors, Fifth Edition, is a current publication that includes relevant revisions to the nomenclature, grading, and prognostication of endocrine tumors based on pathologic characteristics and molecular profile. Additional entities such as thyroid follicular nodular disease, follicular adenoma with papillary architecture, and oncocytic adenoma of the thyroid are included in the benign follicular cell-derived category. Fifth edition WHO has refined the spectrum of papillary thyroid carcinoma (PTC) by aligning invasive encapsulated follicular variant PTCs with follicular thyroid carcinomas. Follicular cell-derived differentiated thyroid carcinomas may also have high-grade features in the absence of morphologic dedifferentiation, and hence, differentiated thyroid carcinomas with high-grade features are now recognized as a distinct morphologic spectrum. The Ki-67 proliferation index reporting is required in all medullary thyroid carcinomas for grading.

Mesenchymal and Non-meningothelial Tumors Involving the Central Nervous System

In the World Health Organization Classification of Brain Tumors Fifth Edition, mesenchymal non-meningothelial tumors involving the central nervous system are divided into three major categories: soft tissue tumors, chondro-osseous tumors, and notochordal tumors. Soft tissue tumors are classified into four groups: fibroblastic and myofibroblastic tumors, vascular tumors, skeletal muscle tumors, and tumors of uncertain differentiation. This article will focus on solitary fibrous tumors(SFTs), which are frequently encountered clinically and continue to undergo classification revisions in the 5th edition, and outline the three newly added histological diagnoses. Although SFTs and hemangiopericytomas occur throughout the body, including the central nervous system, nomenclatures have been different between the classifications of "Tumours of Soft Tissue and Bone" and "Tumours of the Central Nervous System." The latest nomenclature is "SFT" in accordance with the nomenclature of bone and soft-tissue tumors. In addition, three new diagnoses, which are intracranial mesenchymal tumor FET-CREB fusion-positive, CIC-rearranged sarcoma, and primary intracranial sarcoma DICER1-mutant, have been defined based on genetic abnormalities in tumors of uncertain differentiation.

Acral BRAF‐mutated tubular adenoma should be distinguished from HPV42‐related digital papillary adenocarcinoma

Acral <i>BRAF</i>‐mutated tubular adenoma should be distinguished from <scp>HPV42</scp>‐related digital papillary adenocarcinoma

Posterior fossa tumors in children: An update and new concepts.

Posterior fossa tumors account for approximately half of the central nervous system tumors in children. Major technological advances, mainly in the fields of molecular biology and neuroimaging, have modified their classification, leading to a more detailed description of these entities. Into the classic taxonomy, used for many years, new concepts have been incorporated at times eliminating or modifying former ones. A literature search was conducted in PubMed using the medical subject headings involving the five most common pediatric posterior fossa tumors: diffuse midline glioma, medulloblastoma, ependymoma, atypical teratoid/rhabdoid tumor, and pilocytic astrocytoma. Only English published articles in the past 11 years that provided technological, neuroimaging, and molecular biology insight into posterior fossa tumors in children were considered. Substantial changes have been introduced in the nomenclature of pediatric posterior fossa tumors. Diffuse midline gliomas are named based on alterations in histone H3. Molecular rearrangements of medulloblastomas are more important in defining the prognosis than histological variants; therefore, these tumors are currently named based on their molecular subgroups. Posterior fossa ependymomas and atypical teratoid rhabdoid tumor classification have incorporated new groups based on different genetic profiles. Pilocytic astrocytoma has been placed in a new category that distinguishes circumscribed from diffuse entities. Advances in molecular biology and neuroimaging have substantially changed the way pediatric neoplasms are studied. The classical taxonomy has been modified leading to more accurate classifications that are based on the genetic alterations.

Mammary tumors of the dog and the cat: modern approaches to classification and diagnosis (review)

The study of oncopathology of the mammary gland of cats and dogs is a very relevant problem. This is evidenced by the presence of numerous scientific works and experimental research data of scientists from many countries. For a long time, there were no systematic approaches to the nomenclature and classification of canine and feline mammary gland tumors. That is why different countries of the world had their own national approaches to defining these pathologies. Long-term incomplete analysis of clinical cases, gaps in histopathology and interpretation of the obtained results were reflected in contradictory results, inaccuracies in terminology, definition of diagnosis and interpretations. This also inhibited clinical and experimental research, development and testing of effective drugs. Accumulation of clinical data, consolidated work of morphologists became the basis of lively discussions, which in turn was reflected in decisions to create unified classifications. Histological classification became the basis for the division of tumors of the mammary gland of cats and dogs. When conducting a scientific review, modern data from information resources and information from numerous international symposia and conferences were used. The authors also highlighted the key mechanisms of immune regulation of the oncogenic process. The role of immune cells, mediators of immune protection, in the development of oncopathology of the mammary gland is emphasized. Certain immunological tumor markers have been characterized, which are of great importance in the early stages of diagnosis. Special instrumental methods used by veterinary medicine doctors in routine diagnostics are also described. Prospects for the use of cell therapy with the use of modern immunological technologies were also made. The publication has a review and analytical nature and aims to attract the attention of scientists, diagnosticians and clinicians of various profiles to this issue, which will certainly become a continuation in the study of oncopathology. The unified classification will definitely be useful to scientists and practicing doctors, will enrich their knowledge about the mechanisms of tumor growth. We believe that a unified classification will allow researchers to use informative methods of diagnosis – both as a powerful tool in making an accurate diagnosis, and for effective approaches to differentiation and treatment strategies for patients.

Well-differentiated Sertoli-Leydig Cell Tumors (SLCTs) Are Not Associated With DICER1 Pathogenic Variants and Represent a Different Tumor Type to Moderately and Poorly Differentiated SLCTs.

Sertoli-Leydig cell tumors (SLCTs) are uncommon ovarian sex cord-stromal neoplasms which are currently classified into well, moderately, and poorly differentiated and retiform types. Well-differentiated SLCT is the least common and typically occurs in pure form, whereas moderately and poorly differentiated and retiform types often comprise a morphologic spectrum with an admixture of all 3. DICER1 pathogenic variants are very common in SLCTs but, as far as we are aware, have not been reported in well-differentiated neoplasms, although the number of cases studied is small due to the rarity of this neoplasm. We undertook DICER1 molecular testing in a cohort of 18 well-differentiated SLCTs and show all these to be DICER1 wild-type. None of the cases harbored the p. FOXL2 C134W hotspot mutation. Based upon the DICER1 molecular results, together with morphologic observations, we propose that well-differentiated SLCT is an unrelated neoplasm to the more common moderately/poorly differentiated and retiform SLCTs and is a fundamentally distinct and unrelated tumor type within the ovarian sex cord-stromal tumor family. The implications for tumor nomenclature and recommendations for future tumor classification are discussed within the context of tumors collectively known as SLCTs.

Sweat Gland Tumors – A Systematic Review on the Histopathology and Immunohistochemistry

Objective: The categorization of sweat gland tumors has been inconsistent over time. These tumors, having varying potential for malignancy, may behave as indolent neoplasms while others can be highly metastatic. The characteristics of most of these tumors are overlapping and the information of distinctive findings about these neoplasms is imperative. Traditionally, sweat gland tumors were classified as eccrine and apocrine only but recently, this has been found that several sweat gland tumors may exhibit eccrine and apocrine types both. Some tumors exhibit further complex features due to the existence of other differential appearances. This can be in the instance of apocrine neoplasms because of the close embryological link between apocrine glands, hair follicles and sebaceous glands and they can be classified as follicular and/or sebaceous tumors. Cutaneous adnexal neoplasms are a diagnostic challenge, especially for tumors with sweat gland differentiation, due to a huge number of uncommon entities, designation of different terms to the identical tumor following to disagreement about the taxonomy and nomenclature of such tumors. This review article provides updated information about various cancerous sweat gland neoplasms with emphasis on recent conclusions for the diagnosis and generalized therapy of such neoplasms.

Major Changes in 2021 World Health Organization Classification of Central Nervous System Tumors.

The World Health Organization (WHO) published the fifth edition of the WHO Classification of Tumors of the Central Nervous System (WHO CNS5) in 2021, as an update of the WHO central nervous system (CNS) classification system published in 2016. WHO CNS5 was drafted on the basis of recommendations from the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-NOW) and expounds the classification scheme of the previous edition, which emphasized the importance of genetic and molecular changes in the characteristics of CNS tumors. Multiple newly recognized tumor types, including those for which there is limited knowledge regarding neuroimaging features, are detailed in WHO CNS5. The authors describe the major changes introduced in WHO CNS5, including revisions to tumor nomenclature. For example, WHO grade IV tumors in the fourth edition are equivalent to CNS WHO grade 4 tumors in the fifth edition, and diffuse midline glioma, H3 K27M-mutant, is equivalent to midline glioma, H3 K27-altered. With regard to tumor typing, isocitrate dehydrogenase (IDH)-mutant glioblastoma has been modified to IDH-mutant astrocytoma. In tumor grading, IDH-mutant astrocytomas are now graded according to the presence or absence of homozygous CDKN2A/B deletion. Moreover, the molecular mechanisms of tumorigenesis, as well as the clinical characteristics and imaging features of the tumor types newly recognized in WHO CNS5, are summarized. Given that WHO CNS5 has become the foundation for daily practice, radiologists need to be familiar with this new edition of the WHO CNS tumor classification system. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. ©RSNA, 2022.

The 2021 WHO Classification of Tumors of the Central Nervous System: a summary.

The fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS), published in 2021, is the sixth version of the international standard for the classification of brain and spinal cord tumors. Building on the 2016 updated fourth edition and the work of the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy, the 2021 fifth edition introduces major changes that advance the role of molecular diagnostics in CNS tumor classification. At the same time, it remains wedded to other established approaches to tumor diagnosis such as histology and immunohistochemistry. In doing so, the fifth edition establishes some different approaches to both CNS tumor nomenclature and grading and it emphasizes the importance of integrated diagnoses and layered reports. New tumor types and subtypes are introduced, some based on novel diagnostic technologies such as DNA methylome profiling. The present review summarizes the major general changes in the 2021 fifth edition classification and the specific changes in each taxonomic category. It is hoped that this summary provides an overview to facilitate more in-depth exploration of the entire fifth edition of the WHO Classification of Tumors of the Central Nervous System.

Trends in parotidectomy over 30 years in an Australian tertiary care center.

Nomenclature, classification, and management of parotid tumors are constantly evolving; this study was performed to identify temporal trends in histology and facial nerve sacrifice in parotidectomy during a 30-year period (1987-2018). Retrospective analysis of patients treated in a single tertiary-care institution during this time period was performed with analysis of temporal trends. Two thousand eight hundred and fifty-seven parotidectomies were performed; pleomorphic adenoma was the most common histology (34.3%), followed by skin cancer metastases (32.3%). Significant trends noted were increasing age (P < .001), fewer parotidectomies for inflammatory lesions (P < .001), reduced incidence of mucoepidermoid carcinoma (P = .048), increasing incidence of parotidectomy for cutaneous malignancies (P < .001), and reduced facial nerve sacrifice (P = .034). In this contemporary series of parotid pathology, metastatic cutaneous malignancies accounted for a third of cases. Despite reducing facial nerve sacrifice in parotid disease, it is still required in approximately 15% of malignancy and needs to be discussed with all patients preoperatively.

Genomic and Clinicopathologic Characteristics of PRKAR1A-inactivated Melanomas: Toward Genetic Distinctions of Animal-type Melanoma/Pigment Synthesizing Melanoma.

Melanocytic tumors with inactivation of protein kinase A regulatory subunit-α (PRKAR1A) have large oval nuclei and intense pigmentation. Historically, these tumors have been categorized under various names, including epithelioid blue nevus, pigmented epithelioid melanocytoma (PEM) and animal-type melanoma. Although a subset of PEM harbor BRAF activating mutations and biallelic inactivation of PRKAR1A, there are only a few reports of melanomas, or of tumors with genomic alterations beyond those of PEMs. Herein, we describe the clinicopathologic and genetic features of 8 melanomas and tumors that lack PRKAR1α expression by immunohistochemistry but do not fit with conventional PRKAR1A-inactivated melanocytomas. These tumors tended to affect younger patients than conventional melanomas (median age=38 y) and presented as dark brown/black papules and nodules. Histopathologically, they demonstrated nodularity, sometimes in a background of conventional melanoma, and large vesicular nuclei with prominent nucleoli. With the exception of 1 case, the mitotic index was not significantly elevated. Immunohistochemically, all cases showed loss of PRKAR1α and of p16 expression. Seven tumors underwent massively parallel short read (next-generation) sequencing of a panel of 480 cancer-associated genes. Five tumors demonstrated truncating mutations of PRKAR1A and the 2 in which such mutations were not identified demonstrated loss of heterozygosity of the PRKAR1A locus. Four of the tumors harbored BRAF V600E mutations, and 1 harbored a FAM39B-BRAF gene fusion. Another harbored a GNA11 activating mutation. A MAP kinase activating mutation was not identified in the remaining case. Four tumors displayed TERT promoter mutations and chromosomal copy number changes supporting the diagnosis of melanoma. Two cases without these alterations and were classified as "high-grade PRKAR1A-inactivated melanocytomas". The 1 case with widespread metastases demonstrated mutations in TP53 and RB1. Overall, we provide the first genetic characterization of PRKAR1A-inactivated melanomas, discuss the differential diagnosis of heavily pigmented epithelioid melanocytic neoplasms, and propose a new nomenclature for such tumors.

Ovarian Seromucinous Tumors: Pathogenesis, Morphologic Spectrum, and Clinical Issues.

Ovarian seromucinous tumors were introduced in the 2014 World Health Organization (WHO) classification as one of the seven types of ovarian epithelial tumors. They are characterized by frequent association with endometriosis and bilaterality, microscopic appearance of papillary architecture, and admixture of a variety of müllerian-type epithelium. They are considered to be endometriosis-related ovarian neoplasms, along with endometrioid and clear cell tumors; recent molecular studies suggest this particular tumor is a variant of endometrioid tumor. Discrepancies in nomenclature, definition, and morphology of seromucinous tumors appear to be a source of confusion, for both clinicians and general surgicalpathologists. This review summarizes the clinicopathological features of benign, borderline, and malignant seromucinous tumors, as well as controversies regarding these tumors.

Meta-terminology of Ameloblastoma.

One of the primary tasks of systematic biology is the development of our biological nomenclature and classifications. The key purpose for the development of a standard nomenclature for a disease is the need for a common language for the statement of diagnostic terms and for a means or system whereby diagnosis could be suitably recorded without chaos. Odontogenic tumor nomenclature and classification have confused physicians over the years. Ameloblastoma is one such entity among odontogenic tumors, which has continuously changed to be an evolution of the terms and taxonomy used in literature. In this review, we aim to provide a fundamental basis for the understanding of how the etymology and the position of ameloblastoma in odontogenic tumor classification have evolved over the years.

A Perspective on Standardized Tumor Staging, Tumor Nomenclature, and Surgical Pathology Reports

A Perspective on Standardized Tumor Staging, Tumor Nomenclature, and Surgical Pathology Reports