Genetics, Diagnosis, and Management of Hürthle Cell Thyroid Neoplasms.

Hürthle cell lesions have been a diagnostic conundrum in pathology since they were first recognized over a century ago. Controversy as to the name of the cell, the origin of the cell, and even which cells in particular may be designated as such still challenge pathologists and confound those treating patients with a diagnosis of "Hürthle cell" anything within the diagnosis, especially if that anything is a sizable mass lesion. The diagnosis of Hürthle cell adenoma (HCA) or Hürthle cell carcinoma (HCC) has typically relied on a judgement call by pathologists as to the presence or absence of capsular and/or vascular invasion of the adjacent thyroid parenchyma, easy to note in widely invasive disease and a somewhat subjective diagnosis for minimally invasive or borderline invasive disease. Diagnostic specificity, which has incorporated a sharp increase in molecular genetic studies of thyroid tumor subtypes and the integration of molecular testing into preoperative management protocols, continues to be challenged by Hürthle cell neoplasia. Here, we provide the improving yet still murky state of what is known about Hürthle cell tumor genetics, clinical management, and based upon what we are learning about the genetics of other thyroid tumors, how to manage expectations, by pathologists, clinicians, and patients, for more actionable, precise classifications of Hürthle cell tumors of the thyroid.

Analysis of the risk of malignancy associated with the basaloid and oncocytic subtypes of the salivary gland neoplasm of unknown malignant potential (SUMP) category in the Milan system.

BACKGROUND: The salivary gland neoplasm of unknown malignant potential (SUMP) category reflects the cytomorphologic overlap and complexity of reporting salivary gland cytology in the Milan system. It includes neoplasms for which a diagnosis of a specific entity cannot be made and, more importantly, for which a carcinoma cannot be entirely excluded. For risk stratification, the subcategorization of SUMP based on the predominant cell type is recommended. This study was aimed at evaluating the risk of neoplasm (RON) and the risk of malignancy (ROM) of the basaloid and oncocytic subtypes of the SUMP category. METHODS: A retrospective analysis of 482 salivary gland fine-needle aspirations from 2012 to 2019 resulted in 48 SUMP cases. The cytology of these cases was reviewed and reclassified as the basaloid or oncocytic subtype. Surgical follow-up was available for 36 cases. The RON and ROM for each subtype were calculated. RESULTS: The RON and ROM were 100% and 23%, respectively, for monomorphic basaloid tumors and 88% and 58.8%, respectively, for monomorphic oncocytic tumors. The ROM for basaloid tumors was 8.3% without matrix/with minimal matrix and 60% with an nonfibrillary matrix. The ROM for oncocytic tumors was 50% without a cystic background and 60% with a cystic or mucinous background. The difference was not statistically significant for either of the subgroups. CONCLUSIONS: Even though statistically not significant in our study, the differential ROMs within the oncocytic and basaloid subgroups help in the risk stratification of SUMP cases. Further subcategorization based on the stroma and background helps in limiting the differential diagnosis but does not necessarily add to the value of the risk stratification.

Genomic and transcriptomic characterization of the mitochondrial-rich oncocytic phenotype on a thyroid carcinoma background.

We conducted the first systematic omics study of the oncocytic phenotype in 488 papillary thyroid carcinomas (PTC) from The Cancer Genome Atlas. Oncocytic phenotype is secondary to PTC, being unrelated to several pathologic scores. The nuclear genome had low impact on this phenotype (except in specific copy number variation), which was mostly driven by the significant accumulation of mitochondrial DNA non-synonymous and frameshift mutations at high heteroplasmy levels. Energy and mitochondrial-related pathways were significantly enriched in oncocytic tumors that also displayed increased levels of expression for genes involved in autophagy and fusion of mitochondria. Our in vitro tests confirmed that autophagy is increased and functional while mitophagy is decreased in these tumors.

Oncocytic meningiomas: Cases with benign histopathological features and a favorable clinical course.

OBJECT: Oncocytic meningioma has recently been recognized as a distinct morphological variant of intracranial meningothelial neoplasms, and only a few cases have been reported in the literature. The first description of this lesion, which was based on data in six cases, revealed a potentially aggressive nature with a tendency to infiltrate the brain and to recur. However, the true behavior of, and the long-term follow-up data for, such lesions must still be outlined. METHODS: The authors report on five cases of intracranial oncocytic meningiomas. On neuroimaging, the lesions showed the characteristic features of common meningiomas. All patients underwent gross-total removal of the mass together with the adjacent dura mater. No additional treatments were administered. Histologically, the tumors were composed of sheets, nests, and cords of large polygonal neoplastic cells with finely granular cytoplasm. Necrosis was absent in all cases. Mitosis was also absent or exceedingly rare, and no brain cortex infiltration was observed. The follow up ranged from 6 to 54 months (mean 32.4 months). At the last follow-up evaluation, all patients were asymptomatic and magnetic resonance imaging examinations demonstrated no evidence of tumor recurrence. CONCLUSIONS: Data in the presented cases did not confirm a previously described propensity to aggressiveness in this meningioma subtype. In fact, the histological features as well as the long-term favorable clinical course may suggest benign behavior of such neoplasms, as in the common forms of meningiomas.

Morphometrically observable aging changes in the human tongue.

Like the outside parts of the nose and the ear but unlike most other organs, the tongue continues to grow at advanced age. Therefore, internal morphological aging processes must also proceed in a specific way. We used sectioned specimens of the radix linguae from 111 humans. The specimens were fixed in 4% formalin solution, embedded in paraffin, then cut at a thickness of 5 microm and stained with hematoxylin-eosin. The structures of interest were measured with an automatic image analyzing system (SIS, Münster, Germany). The statistical analysis package SPSS was used for correlation and regression analysis and testing of the resulting coefficients. The mean cross-sectional area of the muscle fibers increases sharply during youth, but remains at a high level into old age. After the age of seventy, it increases again. With muscles of the locomotor apparatus, this same parameter decreases after the fifth decade. We have demonstrated the process of adipose tissue formation in muscles and serous glands. Gender differences in the aging process could be clearly shown. Numerous oncocytes were visible in ducts from elder persons.