Contrast-enhanced endoscopic ultrasonography features of a mucoepidermoid carcinoma of the pancreas

Rapidly Progressing Anaplastic Carcinoma of the Pancreas with Mucoepidermoid Carcinoma: An Autopsy Case Report

A 75-year-old man visited our hospital for the examination of a tumor in the pancreas. Computed tomography showed an 85×85-mm low-density tumor in the pancreas. The tumor was pathologically diagnosed as poorly differentiated carcinoma by endoscopic ultrasound-guided fine-needle aspiration. Although we started chemotherapy, the patient died 84 days after the diagnosis. An autopsy demonstrated a ruptured anaplastic carcinoma with mucoepidermoid carcinoma of the pancreas. Anaplastic carcinoma with mucoepidermoid carcinoma is a very rare histologic subtype of pancreatic carcinoma, so pathological findings are important for predicting the patient's prognosis. Physicians should be aware of this rare but fatal disease.

Targeted-Gene Sequencing and Bioinformatics Analysis of Patients with Pancreatic Mucoepidermoid Carcinoma: A Case Report and Literature Review

Background

Primary pancreatic mucoepidermoid carcinoma (MEC) is an extremely rare malignant tumor with unclear etiology and pathogenesis. There are only eleven reported cases in English papers published from 1959 to 2020. MEC generally occurs in the salivary gland, but cases in the pancreas have also been reported. Although being considered as a low-grade indolent carcinoma, pancreatic MEC always invades the surrounding lymph node and metastasizes. The prognosis of pancreatic MEC is unsatisfactory. To date, the genetic alterations, mechanistic relationships among mutated genes and signaling pathways of pancreatic MEC are unclear.

Patient and Methods

This paper presents a case of rare primary pancreatic MEC in a 56-year-old male patient with liver metastasis. Radical surgery of distal pancreatectomy and radiofrequency ablation (RFA) of two liver metastatic lesions is conducted. Targeted-gene sequencing and bioinformatics analysis tools, including STRING, DAVID, cBioPortal, DGidb and Human Protein Atlas database (HPA), are used to clarify the biological functions and features of mutated genes in pancreatic MEC.

Results

Eight gene mutations (TP53, KRAS, ATR, FLI1, FLT4, MAGI2, RBM10, and TNFAIP3) were observed, and a tumor mutation burden (TMB) of 5.6 muts/Mb was calculated in the pancreatic MEC using targeted-gene sequencing. The patient subsequently underwent adjuvant chemotherapy and died three months after surgery. Gene–gene interaction network was constructed, which showed the significant interactions among eight mutated genes. In terms of the functions and pathways of eight gene mutations based on GO and KEGG, 20 tumor-related results are presented in this paper, Furthermore, the biological functions and features of pancreatic MEC are further compared with pancreatic ductal adenocarcinoma.

Conclusion

Pancreatic MEC requires early and effective treatment, and lymph node metastases and multiple organ metastases were unfavorable prognostic factors. Pancreatic MEC can be compared with other pancreatic cancers that have characteristic clinical phenotype, molecular alterations, functional information and enrichment pathway.