An miRNA Signature Predicts Grading of Pancreatic Neuroendocrine Neoplasms.

BACKGROUND/AIM: Grading pancreatic neuroendocrine neoplasms (PNENs) via mitotic rate and Ki-67 index score is complicated by interobserver variability. Differentially expressed miRNAs (DEMs) are useful for predicting tumour progression and may be useful for grading. PATIENTS AND METHODS: Twelve PNENs were selected. Four patients had grade (G) 1 pancreatic neuroendocrine tumours (PNETs); 4 had G2 PNETs; and 4 had G3 PNENs (2 PNETs and 2 pancreatic neuroendocrine carcinomas). Samples were profiled using the miRNA NanoString Assay. RESULTS: There were 6 statistically significant DEMs between different grades of PNENs. MiR1285-5p was the sole miRNA differentially expressed (p=0.03) between G1 and G2 PNETs. Six statistically significant DEMs (miR135a-5p, miR200a-3p, miR3151-5p, miR-345-5p, miR548d-5p and miR9-5p) (p<0.05) were identified between G1 PNETs and G3 PNENs. Finally, 5 DEMs (miR155-5p, miR15b-5p, miR222-3p, miR548d-5p and miR9-5p) (p<0.05) were identified between G2 PNETs and G3 PNENs. CONCLUSION: The identified miRNA candidates are concordant with their patterns of dysregulation in other tumour types. The reliability of these DEMs as discriminators of PNEN grades support further investigations using larger patient populations.

An Analysis of the Impact of COVID-19 Pandemic-related Lockdown Measures on a Large Gastrointestinal Pathology Service in the United States.

BACKGROUND/AIM: The coronavirus disease 2019 (COVID-19) pandemic prompted global recommendations to delay non-urgent endoscopic procedures to limit the spread of SARS-COV-2, but such delays had unprecedented impact on the delivery of healthcare. Being a large specialty GI Pathology service, we sought to analyze the effect of the pandemic on the frequency of GI malignancies in our department. PATIENTS AND METHODS: Based on the electronic search of departmental pathology records, we compared the total numbers of cancer diagnoses (primary and metastatic) from various GI biopsy sites during the 12-month pre- and post-pandemic periods. We summarized patient demographics and analyzed pertinent histopathologic data. RESULTS: For all GI biopsy sites, the number of intramucosal/invasive malignancies reported during the one-year pre-COVID-19 pandemic (pre-COVID) and post-COVID-19 pandemic national lockdown (post-COVID) observation periods were 146 and 218, respectively. Among these, 32 and 70 malignancies were reported for the first quarter (representing the earliest post-lockdown period), 29 and 53 for the second, 41 and 54 for the third, and 44 and 41 for the fourth quarter. During the first two quarters of the post-COVID observation period, the increase in malignant diagnoses was most profound, showing 119% post-COVID increase compared to the pre-COVID levels. Of the two main primary histologic types of large intestinal carcinomas [adenocarcinoma (ADC) and squamous cell carcinoma (SCC)], the most profound post-COVID increase was noted in SCCs (136% vs. 58% for ADCs). CONCLUSION: Compared to the pre-pandemic baseline, the COVID-19 pandemic caused a major increase in biopsy diagnoses of GI cancers in our department. The most plausible explanations for this trend include inevitable lockdowns to minimize the spread of SAR-COV2, which affected GI endoscopy procedure schedules/re-schedules as well as patient response and adaptation to emerging post-COVID GI healthcare patterns. The COVID-19 pandemic's long-term impact on the health of GI cancer patients will need to be determined through systematic analyses by multi-disciplinary teams.

Pancreatic-type Mixed Acinar-neuroendocrine Carcinoma of the Stomach: A Case Report and Literature Review.

Background: Pancreatic-type mixed acinar-neuroendocrine carcinoma (PMANEC) in the stomach is very rare. We report a case of PMANEC that was initially misdiagnosed as a gastric neuroendocrine tumor. Case Report: A 63-year-old female was found to have a gastric mass by histology and immunohistochemistry. The tumor had a heterogenous histology, with areas resembling pancreatic acinar cell carcinoma and other areas exhibiting neuroendocrine features. Only the neuroendocrine component was present in the initial biopsy, resulting in the erroneous diagnosis of gastric neuroendocrine tumor. Evaluation of the final resected tumor revealed cells expressing pancreatic exocrine markers, including trypsin and chymotrypsin and BCL10 immune signaling adaptor. Large areas of the tumor (>30%) were also positive for chromogranin A and synaptophysin. The final diagnosis was PMANEC. Conclusion: This type of gastric cancer is rare and may cause diagnostic difficulty, especially if only the neuroendocrine component of the tumor is sampled in a biopsy.