Screening for DNA copy number aberrations in mucinous adenocarcinoma arising from the minor salivary gland: two case reports

Adenosquamous Carcinomas and Mucinous Adenocarcinoma of the Minor Salivary Glands: Immunohistochemical and Molecular Insights

There is confusion about the diagnosis, histogenesis and taxonomical efforts regarding adenosquamous carcinomas (ASCs) and mucinous adenocarcinomas (MACs), especially with calls for reconsidering the nature of high-grade mucoepidermoid carcinoma (MEC). This study aims to compare the genetic profiles of ASCs and MACs that have been previously reported in the literature and investigate if either ASC or MAC is closer in genetic mutations to high-grade MEC. Systematic searches in the NCBI, Web of Science, and Scopus databases were performed between January 2000 and August 2022. The retrieved genetic mutations were processed and annotated. Protein–protein network analysis was conducted for each neoplasm. The results were viewed and discussed in terms of molecular oncogenesis of ASCs and MACs at different topographies. Molecular profile mapping was conducted by annotating all the retrieved genes for each neoplasm using genetic network analysis (Cystoscape software program). The genetic profile of each lesion was compared to that of high-grade MEC. To conclude, both genetic profiles do not tend to intersect specifically with high-grade MEC, except for the generic mutations commonly detected in all high-grade head and neck tumors. However, the availability of data on the molecular profile of each lesion limits the generalizability of the findings of this study.

Cytogenomic Abnormalities in 19 Cases of Salivary Gland Tumors of Parotid Gland Origin

Salivary gland tumors (SGTs) of parotid origin are a group of diverse neoplasms which are difficult to classify due to their rarity and similar morphologic patterns. Chromosome analysis can detect clonal abnormalities, and array comparative genomic hybridization (aCGH) analysis can define copy number alterations (CNAs) from tumor specimens. Of the 19 cases of various types of SGTs submitted for cytogenomic analyses, an abnormal clone was detected in nine cases (47%), and CNAs were detected in 14 cases (74%). Recurrent rearrangements involving the PLAG1 gene at 8q12, recurrent CNAs including deletions of 6q, 9p (CDKN2A), and 17p (TP53), loss of Y chromosome, and gain of chromosome 7 were defined from these cases. Combined karyotyping and aCGH analyses could improve diagnostic yield. Future study for more precisive correlation of SGT classification with cytogenomic abnormalities will facilitate better diagnosis and treatment.

Primary mucinous carcinoma of buccal mucosa: a rare case report

Minor salivary gland tumors of oral cavity are very rarely encountered in day-to-day practice. Mucinous adenocarcinoma is very rare, and is commonly seen in elderly males. Palate and buccal mucosa is the commonest site. Wide local excision is the treatment. Histology shows tumor cells floating in pools of mucin, compartmentalized by fibrous tissue. Metastasis is a close mimicker, however with an evidence of negative scan and minor salivary gland proliferation in adjacent tissue diagnosis can be made. Mucin stains and immunohistochemistry can be used to support the diagnosis in problematic cases. We are presenting a rare case of mucinous adenocarcinoma-cheek in a 54-year-old male who came with gradually progressive swelling in the left buccal mucosa since 3 months and after wide excision, no evidence of recurrence was noted in 1 year and 3 months of follow up period.

The lipid kinase PI4KIIIβ and the eEF1A2 oncogene co-operate to disrupt three-dimensional in vitro acinar morphogenesis

The study of in vitro morphogenesis is fundamental to understanding neoplasia since the dysregulation of morphogenic pathways that create multi-cellular organisms is a common hallmark of oncogenesis. The in vitro culture of human breast epithelial cells on reconstituted basement membranes recapitulate some features of in vivo breast development, including the formation of a three-dimensional structure termed an acinus. Importantly, the capacity to disrupt in vitro acinar morphogenesis is a common property of human breast oncogenes. In this report, we find that phosphatidylinositol 4-kinase IIIβ (PI4KIIIβ), a lipid kinase that phosphorylates phosphatidylinositol (PI) to PI(4)P, disrupts in vitro mammary acinar formation. The PI4KIIIβ protein localizes to the basal surface of acini created by human MCF10A cells and ectopic expression of PI4KIIIβ induces multi-acinar devlopment. Furthermore, expression of an oncogenic PI4KIIIβ activator, eEF1A2 (eukaryotic elongation factor 1 alpha 2), phenocopies the PI4KIIIβ multi-acinar phenotype. Ectopic expression of PI4KIIIβ or eEF1A2 alters the localization of PI(4)P and PI(4,5)P(2) within acini, indicating the importance of these lipids in acinar development. Our work shows that PI4KIIIβ, eEF1A2 and PI(4)P likely play an important role in mammary neoplasia and acinar development.