Thymus-like phenotype in benign lymphoepithelial neoplasms of salivary glands: clinicopathological and molecular characterization and reappraisal of relationship to non-sebaceous lymphadenoma.

Benign lymphoepithelial tumors of salivary glands had been restricted to sebaceous and non-sebaceous (NSLA) lymphadenomas. However, salivary neoplasms recapitulating carcinoma showing thymus-like elements (CASTLE) have been the subject of recent case reports. We reviewed clinicopathological, immunohistochemical, and molecular findings in 20 salivary gland tumors with thymus-like phenotype (18 histologically benign and two with malignant component).

Biphasic Myoepithelial Carcinoma With 5p/5q Loss: Morphomolecular Characterization and Provisional Designation of a Proposed Novel Salivary Tumor Entity.

Salivary gland tumors are diagnostically challenging due to major diversity of benign and malignant tumors with enormous intra-tumorous and inter-tumorous heterogeneity and, hence, frequently overlapping histologic features. DNA methylation has greatly enhanced tumor classification in several organs and led to the identification of previously unrecognized entities. In a recent study on DNA methylation of salivary gland tumors, we had identified a group of unclassifiable tumors.

Unveiling the molecular landscape and clinically relevant molecular heterogeneity of mucosal melanoma of the head and neck region.

Aims: Mucosal melanoma of the head and neck (MM-H&N) is an aggressive disease known for its frequent residual tumours/relapses (RT/R) at the surgical site, as well as eventual metastases. Our understanding of the MM-H&N mutational landscape, together with the correlation of specific mutations with clinical-pathological features, is significantly less comprehensive compared to that of cutaneous melanoma. Additionally, the mutational status of consecutive samples collected from single patients has not been investigated, which limits our ability to characterise the prognosis and treatment options for this patient subset.

Sinonasal adenoid cystic carcinomas accompanied by seromucinous hamartoma and/or atypical sinonasal glands arising from seromucinous hamartoma: insight into their histogenesis.

The pathology of reactive, dysplastic, and neoplastic sinonasal seromucinous glands is complex, and their contribution to tumorigenesis of sinonasal carcinomas remains controversial. In our practice, we have observed the presence of respiratory epithelial adenomatoid hamartomas (REAH) and seromucinous hamartomas (SH) associated with adenoid cystic carcinomas (AdCC) in a subset of cases. In many of these cases, genuine atypical features and dysplastic characteristics of the glands were noted at the interface of SH and AdCC.

TFE3 -rearranged Head and Neck Neoplasms : Twenty-two Cases Spanning the Morphologic Continuum Between Alveolar Soft Part Sarcoma and PEComa and Highlighting Genotypic Diversity.

TFE3 rearrangements characterize histogenetically, topographically, and biologically diverse neoplasms. Besides being a universal defining feature in alveolar soft part sarcoma (ASPS) and clear cell stromal tumor of the lung, TFE3 fusions have been reported in subsets of renal cell carcinoma, perivascular epithelioid cell tumor (PEComa), epithelioid hemangioendothelioma and ossifying fibromyxoid tumors. TFE3 -related neoplasms are rare in the head and neck and may pose diagnostic challenges.

S2k guideline basal cell carcinoma of the skin (update 2023).

Basal cell carcinoma is the most common malignant tumor in the fair-skinned population and its incidence continues to rise. An update of the S2k guideline with the participation of all specialist societies familiar with the clinical picture and previous literature research is of great importance for the quality of care for affected patients. In addition to epidemiology, diagnostics and histology are discussed.

Sclerosing mucoepidermoid carcinoma of salivary glands.

Sclerosing mucoepidermoid carcinoma (SMEC) of the salivary glands is a rare variant of low-grade mucoepidermoid carcinoma with scanty cellular atypia characterized by marked fibrosis/sclerosis and a rich inflammatory infiltrate. Herein, we report 25 unpublished cases of SMEC, two of them with prominent eosinophilia (2/25; 8%) and three with abundant IgG4-positive plasma cells (3/25; 12%). In our series of salivary SMEC, molecular analysis using fluorescence in situ hybridization (FISH) and/or next-generation sequencing (NGS) provided evidence of MAML2 gene rearrangement in 18 cases of the 21 analyzable cases tested (86%), while this gene locus was intact in 3 cases (14%).

S3 guideline "actinic keratosis and cutaneous squamous cell carcinoma" - update 2023, part 2: epidemiology and etiology, diagnostics, surgical and systemic treatment of cutaneous squamous cell carcinoma (cSCC), surveillance and prevention.

Actinic keratosis (AK) are common lesions in light-skinned individuals that can potentially progress to cutaneous squamous cell carcinoma (cSCC). Both conditions may be associated with significant morbidity and constitute a major disease burden, especially among the elderly. To establish an evidence-based framework for clinical decision making, the guideline "actinic keratosis and cutaneous squamous cell carcinoma" was updated and expanded by the topics cutaneous squamous cell carcinoma in situ (Bowen's disease) and actinic cheilitis.

[Why is the histomorphological diagnosis of small salivary gland tumours so much more difficult?].

There is a widespread impression among clinicians and pathologists that the histomorphological diagnosis of minor salivary gland tumours is more difficult and more frequently misdiagnosed than that of major glands. This is based on subjective clinical impression; scientific proof of and potential reasons for this difference are lacking. We identified 14 putative clinical, histopathological and combined clinical-histological reasons and four consequences, which together could explain the perceived greater difficulty of diagnosing minor gland tumours.

New entity of microsecretory adenocarcinoma of salivary glands: first case with recurrence and metastases - proof of malignancy.

Microsecretory adenocarcinoma (MSA) of the salivary glands is a recently described entity. Due to lack of reported metastases, in 30 cases described until now, the designation as low-grade cancer was so far solely based on demonstration of local tumor invasion and in a single case with perineural invasion. We herein describe the first documented case with local recurrence and hematogenous metastases.

HMGA2-WIF1 Rearrangements Characterize a Distinctive Subset of Salivary Pleomorphic Adenomas With Prominent Trabecular (Canalicular Adenoma-like) Morphology.

Most of salivary gland neoplasms (benign and malignant) are characterized by recurrent gene fusions. Pleomorphic adenoma (PA), the most frequent salivary gland tumor, is driven by chromosomal rearrangements involving PLAG1 mapped to 8q12 and HMGA2 mapped to 12q13-15 in most cases. Multiple fusion partners have been identified including CTNNB1, FGFR1, LIFR, CHCHD7 and TCEA for PLAG1 fusions and NFIB, WIF1 and FHIT for HMGA2 fusions.

Why is the histomorphological diagnosis of tumours of minor salivary glands much more difficult?

Aims: There is a widespread perception among clinicians and pathologists that the histomorphological assessment of minor salivary gland (MinSG) tumours is more difficult and hampered by more misdiagnoses than that of major salivary gland tumours. This is based on a vague, subjective clinical impression, lacking scientific proof. The aim of the present study was to identify and statistically verify potential reasons that could explain this difference.

Microsecretory Adenocarcinoma of Salivary Glands: An Expanded Series of 24 Cases.

Microsecretory adenocarcinoma (MSA) is a recently described salivary gland tumor with a characteristic histologic and immunophenotypic profile and recurrent MEF2C-SS18 fusions. Because only six cases of MSA have been published, its complete clinicopathologic spectrum is unclear, and its biologic behavior has not been documented. Here, we present an updated and expanded experience of 24 MSA cases.

ALK Rearrangements Characterize 2 Distinct Types of Salivary Gland Carcinomas: Clinicopathologic and Molecular Analysis of 4 Cases and Literature Review.

The majority of salivary gland carcinomas are characterized by recurrent gene fusions that proved highly valuable diagnostically, but only rarely of therapeutic impact. Most of these fusion-positive carcinomas belong to the low-grade or intermediate-grade biological category. To date, only 5 cases of salivary gland carcinomas carrying an oncogenic ALK fusion have been reported in 4 recent studies, but their phenotypic spectrum and their nosological classification remain uncharacterized.

[Is there a new salivary gland? - Rather not!].

In October 2020, the lay press, but also some medical journals and websites reported the putative discovery of a new salivary gland in the nasopharynx based on prostate-specific membrane antigen positron emission tomography computed tomography (PSMA-PET/CT) examinations. As an interdisciplinary group from the fields of anatomy, pathology, nuclear medicine and otorhinolaryngology, we come to the view that an accumulation of minor salivary glands has been described here. Minor salivary glands in the nasopharynx and in the peritubar region have been described at least since 1866.