Primary intestinal-type adenocarcinoma of the buccal mucosa: A case report and literature review

Primary intestinal-type adenocarcinoma: Report of a rare case involving a young patient

The aim of this report was to describe a rare example of sporadic intestinal-type adenocarcinoma of the major salivary glands and oral cavity. A 23-year-old female patient presented an asymptomatic, progressive-growing mass involving the floor of mouth and the left submandibular gland. Fine-needle aspiration cytology, imaging exams, and surgical specimen findings were consisted with the diagnosis of primary intestinal-type adenocarcinoma, despite its similar immunohistochemical results with colorectal adenocarcinoma. Adjuvant chemotherapy and radiotherapy were performed, but the patient developed multiple metastatic lesions after one year of initial the intervention and deceased following 13 months of follow-up, despite several therapeutic efforts. We verified that sporadic cases of primary intestinal-type adenocarcinoma still lack information regarding etiology and tumorigenesis, especially in young and females. A complete diagnostic workflow is indispensable to rule out the presence of primary colorectal adenocarcinoma.

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.

Salivary gland papillary adenocarcinoma with intestinal-like features: Clinicopathologic, immunohistochemical, and genetic study of six cases

BACKGROUND

Salivary gland tumors with papillary architecture and intestinal-like mucinous cytologic features are rare. Their clinicopathologic and genetic features are not fully understood, and whether they represent one separate entity remains unclear.

METHODS

Six salivary adenocarcinomas with papillary architecture and intestinal-like mucinous cytologic features were reported. Immunostaining was done for CK7, CK20, CDX2, SOX10, S100, MUC1, MUC2 and MUC5AC. Tumor DNA samples were extracted for Sanger sequencing. Previously reported morphology-analogous cases were reviewed.

RESULTS

Six cases involved the palate (2), retromolar region (1), submandibular region (1), tongue (1), and mandible (1). Five cases were followed up, with one case of recurrence one year after surgery, one death from cerebral infarction seven days after surgery, and three cases without signs of recurrence or metastasis over five years. All cases had abundant mucinous production and presented a typical immunophenotype common to salivary primaries, CK7 & MUC1 positive, CK20 & CDX-2 negative. Sanger sequencing demonstrated recurrent AKT1 E17K mutations in four cases (4/6, 66.7%). A review of reported salivary intestinal-like tumors revealed 3 out of 13 cases presented with papillary morphology and CDX-2 negative. Some salivary papillary neoplasms with mucinous cytologic features termed as intraductal papillary neoplasms or mucinous adenocarcinomas were also reported with AKT1 E17K mutations.

CONCLUSION

We describe 6 cases of salivary gland papillary adenocarcinoma with intestinal-like mucinous cytologic features, which are different from conventional intestinal-type adenocarcinoma, presenting a consistent immunophenotype of CK7 & MUC1 positive, CK20 & CDX-2 negative and exhibiting recurrent AKT1 E17K mutations.