Clinical progression of B cell chronic lymphocytic leukemia (B-CLL) reflects the clone’s antigen receptor (BCR) and involves stroma-dependent B-CLL growth within lymphoid tissue. Uniformly elevated expression of Toll-like receptor 9 (TLR-9), occasional MYD88 mutations, and BCR specificity for DNA or antigens physically linked to DNA together suggest that TLR-9 signaling is important in driving B-CLL growth in patients. Nevertheless, reports of apoptosis following B-CLL exposure to CpG oligodeoxynucleotide (ODN) raised questions about a central role for TLR-9. Because normal memory B cells proliferate vigorously to ODN + interleukin-15 (IL-15), a cytokine found in stromal cells of bone marrow, lymph nodes, and spleen, we examined whether this was true for B-CLL cells. Through a CFSE-based assay for quantitatively monitoring in-vitro clonal proliferation/survival, we show that IL-15 precludes TLR-9-induced apoptosis and permits significant B-CLL clonal expansion regardless of the clone’s BCR mutation status. A robust response to ODN+IL-15 was positively linked to presence of chromosomal anomalies (trisomy-12 or ataxia telangiectasia mutated (ATM) anomaly + del13q14), and negatively linked to a very high proportion of CD38+ cells within the blood-derived B-CLL population. Furthermore, a clone’s intrinsic potential for in-vitro growth correlated directly with doubling time in blood, in the case of B-CLL with IGHV-unmutated BCR and <30% CD38+ cells in blood. Finally, in-vitro high-proliferator status was statistically linked to diminished patient survival. The above findings, together with immunohistochemical evidence of apoptotic cells and IL-15-producing cells proximal to B-CLL pseudofollicles in patient spleens, suggest that collaborative ODN and IL-15 signaling may promote in-vivo B-CLL growth.

Background and Aims Liver injury due to COVID-19 is being increasingly recognized. Abnormal liver chemistry tests of varying severities occur in a majority of patients. However, there is a dearth of accompanying liver histologic studies in these patients. Methods: The current report details the clinical courses of two patients having severe COVID-19 hepatitis. Liver biopsies were analyzed under light microscopy, portions of liver tissue were hybridized with a target probe to the SARS-CoV-2 S gene, and small sections from formalin-fixed paraffin embedded liver tissue were processed for electron microscopy. Results The liver histology of both cases showed a mixed inflammatory infiltrate with prominent bile duct damage, endotheliitis and many apoptotic bodies. In-situ hybridization and electron microscopy suggest the intrahepatic presence of the severe acute respiratory syndrome corona virus-2 (SARS-CoV-2), the findings of which may indicate the possibility of direct cell injury. Conclusions Based on the abundant apoptosis and severe cholangiocyte injury, these histopathological changes suggest a direct cytopathic injury. Furthermore, some of the histopathological changes may resemble acute cellular rejection occurring after liver transplantation. These two cases demonstrate that severe COVID-19 hepatitis can occur even in the absence of significant involvement of other organs.

Although the overall five-year survival of patients with pancreatic ductal adenocarcinoma (PDAC) is dismal, there are survival differences between cases with clinically and pathologically indistinguishable characteristics, suggesting that there are uncharacterized properties that drive tumor progression. Recent mRNA sequencing studies reported gene-expression signatures that define PDAC molecular subtypes that correlate with differences in survival. We previously identified Keratin 17 (K17) as a negative prognostic biomarker in other cancer types. Here, we set out to determine if K17 is as accurate as molecular subtyping of PDAC to identify patients with the shortest survival. K17 mRNA was analyzed in two independent PDAC cohorts for discovery (n = 124) and validation (n = 145). Immunohistochemical localization and scoring of K17 immunohistochemistry (IHC) was performed in a third independent cohort (n = 74). Kaplan-Meier and Cox proportional-hazard regression models were analyzed to determine cancer specific survival differences in low vs. high mRNA K17 expressing cases. We established that K17 expression in PDACs defines the most aggressive form of the disease. By using Cox proportional hazard ratio, we found that increased expression of K17 at the IHC level is also associated with decreased survival of PDAC patients. Additionally, within PDACs of advanced stage and negative surgical margins, K17 at both mRNA and IHC level is sufficient to identify the subgroup with the shortest survival. These results identify K17 as a novel negative prognostic biomarker that could inform patient management decisions.

Pancreatic cancer (PC) is a deadly disease with a dismal 5-year survival rate of <6%. The currently limited treatment options for PC underscore the need for novel chemopreventive and therapeutic agents. Accumulating evidence indicates that aspirin use is associated with a decreased risk of PC. However, the anticancer properties of aspirin are restricted by its gastrointestinal toxicity and its limited efficacy. Therefore, we developed phospho-aspirin (PA; MDC-22), a novel derivative of aspirin, and evaluated its chemopreventive efficacy in preclinical models of PC. PA inhibited the growth of human PC cell lines 8–12 fold more potently than aspirin; based on the 24-h IC50 values. In a Panc-1 xenograft model, PA, at a dose of 100 mg/kg/d ×5/wk for 30 days, reduced tumor growth by 78% (p<0.01 vs vehicle control). Furthermore, PA prevented pancreatitis-accelerated acinar-to-ductal metaplasia in mice with activated Kras. In p48-Cre;KrasG12D mice, cerulein treatment (6 hourly injections 2×/wk × 3 wks) led to a significant increase in ductal metaplasia, replacing the majority of the exocrine compartment. Administration of PA 100 mg/kg/d ×5/wk for 21 days (starting on the first day of cerulein injection) inhibited the acinar-to-ductal metaplasia, reducing it by 87% (p<0.01, vs cerulein-treated control). PA appeared to be safe, with the animals showing no signs of toxicity during treatment. Mechanistically, PA inhibited EGFR activation in PC, an effect consistently observed in PC cells, primary acinar explants and in vivo. In conclusion, our findings indicate that PA has strong anticancer efficacy in preclinical models of PC, warranting its further evaluation.

Acinar cystic transformation (ACT), also known as “acinar cell cystadenoma,” is a rare and newly recognized benign pancreatic cystic neoplasm. However, its true malignant potential remains unknown. Here, we report a case of ACT with 15-year follow-up. A 10-year-old female initially presented with abdominal pain and was found to have a cystic lesion in the region of pancreatic head on computed tomography scan. She underwent an exploratory laparotomy, and the intraoperative biopsy of the cyst wall showed a true pancreatic cyst without malignancy. Her symptoms subsequently resolved, and she was placed under close ultrasound surveillance. For the next fifteen years, the patient was asymptomatic without any complications and had a successful pregnancy. Surveillance showed the tumor grew in size from 4.2 cm to 6.2 cm in diameter. In the latest five months, she noted occasional abdominal pain. A pylorus-preserving pancreaticoduodenectomy was performed. The resected cystic lesion was multilocular and lined by a single layer of bland epithelium ranging from nondescript flat/cuboidal epithelium to apparent acinar cells which were strongly positive for trypsin, so the final diagnosis was confirmed to be ACT. The prior biopsy was retrospectively reviewed to reveal similar epithelial lining. To the best of our knowledge, this is the longest period of follow-up for ACT to date. Our findings suggest that ACT is a slow-growing neoplasm without malignant transformation after fifteen years. Therefore, we recommend biopsy for histologic diagnosis followed by close ultrasound surveillance without surgical intervention in asymptomatic or young ACT patients.

Mixed neuroendocrine-nonneuroendocrine neoplasms (MiNENs) are a group of rare tumors previously known as mixed adenoneuroendocrine carcinomas (MANECs). The neuroendocrine component is high-grade and may consist of small-cell carcinoma or large-cell neuroendocrine carcinoma. The nonneuroendocrine component may consist of adenocarcinoma or squamous cell carcinoma. We report a unique case of a MiNEN with trilineage differentiation: large-cell neuroendocrine carcinoma, squamous cell carcinoma, and adenocarcinoma. The reported patient presented with symptoms of an upper gastrointestinal bleed and was ultimately diagnosed with a MiNEN with trilineage differentiation. This is the first report of this exceedingly rare tumor type to include next-generation sequencing of the 3 separate tumor entities. In addition, we review the current literature and discuss the role of next-generation sequencing in classifying and treating MiNEN tumors.

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Tumor budding at the invasive tumor front (peritumoral budding) is an established prognostic factor in colorectal cancer. However, the significance of intratumoral budding (ITB) in pretreatment biopsies is still uncertain. Our study aims to investigate the association of ITB and tumor microenvironment in pretreatment rectal cancer biopsies with pathologic response to neoadjuvant chemoradiotherapy. Pretreatment biopsies of low-grade rectal cancer from 37 patients who underwent resection after neoadjuvant chemoradiotherapy were retrospectively reviewed to evaluate ITB, type of tumor stroma, and intraepithelial lymphocytes. ITB was counted on a single hotspot in 1 HPF upon pan-keratin immunohistochemical staining. Intraepithelial lymphocytes was graded semiquantitatively as "absent" ( ≤ 2/HPF) or "present" ( > 2/ HPF). The tumor stroma was classified as either immature type or maturing type. In pretreatment biopsies, ITB was observed in 34/37 patients (92%). High-grade ITB was significantly associated with a poor pathologic response to neoadjuvant chemoradiotherapy (tumor regression score 2 to 3, P < 0.001; and higher posttreatment T stage, P = 0.002). Immature type of stroma was significantly associated with both high-grade ITB in biopsies (P = 0.02) and a poor pathologic response to neoadjuvant chemoradiotherapy (tumor regression score 2 to 3, P = 0.005). In multivariate analysis, ITB and the type of stroma remained the significant parameters for prediction of response to neoadjuvant treatment. Our study indicates that ITB and tumor microenvironment in pretreatment biopsies are strong predictors of response to neoadjuvant chemoradiotherapy, which may assist risk stratification and clinical management in rectal cancer patients.