Expression of CD117, CK17, CK20, MUC4, villin and mismatch repair deficiency in pancreatic intraductal papillary mucinous neoplasm.

Among pancreatic intraductal papillary neoplasms, gastric, intestinal, and pancreatobiliary intraductal papillary mucinous neoplasm (IPMN), intraductal oncocytic papillary neoplasm (IOPN), and intraductal tubulopapillary neoplasm (ITPN) have been defined, differing regarding association with invasive carcinoma and prognosis. Immunohistochemistry (IHC) can help in the distinction of these neoplasms, but a proportion is unclassifiable using recommended markers. Hence, additional markers useful for the typing of pancreatic intraductal papillary neoplasms are needed. The reported frequencies of the different types of IPMNs in surgical series vary to some extent, and such data based on Danish patients are currently lacking. Besides, the role of mismatch repair (MMR) deficiency in these neoplasms has not been fully elucidated. We aimed to evaluate the frequency of different types of pancreatic intraductal papillary neoplasms in a Danish cohort. Furthermore, we aimed to examine the utility of CD117, CK17, CK20, MUC4, and villin as markers for their distinction, in addition to the recommended markers MUC1, MUC2, MUC5AC, MUC6 and CDX2, and to evaluate the frequency of MMR deficiency. We typed 40 consecutively resected pancreatic intraductal papillary neoplasms according to the WHO criteria from 2019. IHC for CD117, CDX2, CK17, CK20, MLH1, MSH2, MSH6, MUC1 (H23), MUC1 (Ma695), MUC2, MUC4, MUC5AC, MUC6, PMS2, and villin was performed and evaluated using a five-tiered semiquantitative scale. A subset of the tumours was examined with PCR for microsatellite instability (MSI). Most tumours were intestinal (40 %) and gastric (40 %) IPMNs, followed by pancreatobiliary (17 %) IPMNs and IOPN (3 %). All cases were MMR proficient. We found a higher expression of MUC4, CK20 and villin in intestinal compared to gastric IPMNs (p < 0.01, p < 0.001 and p < 0.001). MUC4 was more strongly expressed in intestinal compared to pancreatobiliary IPMNs, while the opposite was found for CK17 (p < 0.05 and p < 0.05). IOPN showed strong CD117 expression (score 4), while all gastric IPMNs were negative and 50 % and 29 % of intestinal and pancreatobiliary IPMNs only showed weak expression (score 1). Our data suggest that CK20, MUC4 and villin may aid in the identification of intestinal IPMNs, while CK17 and CD117 may aid in the identification of pancreatobiliary IPMNs and IOPN, in some cases. However, additional studies evaluating these markers in pancreatic intraductal papillary neoplasms are needed.

Mixed acinar-neuroendocrine carcinoma of the pancreas: a case report and a review.

A 62-year-old woman presented with abdominal discomfort. Imaging studies showed a tumor in the pancreatic tail. At contrast-enhanced CT and macroscopy, the tumor showed cystic, solid and hemorrhagic areas. Histologically, the tumor was well-circumscribed and entirely encapsulated. Some of the tumor cells in the cystic areas were reminiscent of acinar cells, and the majority was arranged in a solid growth pattern. Immunohistochemistry revealed >30% positivity for chymotrypsin, chromogranin A, synaptophysin, and CD56. The diagnosis of a mixed acinar-neuroendocrine carcinoma (MAEC) was made. Review of the English-language literature revealed 44 previously published cases of resected MAECs. We found that, compared to pure acinar cell carcinoma, patients with MAEC have a slightly higher age and are less frequently males, as the male / female ratio was almost equal. The histogenesis of MAEC is still controversial. Due to the small number of cases it is at present not possible to define an evidence-based optimal treatment strategy for these patients.

Incidental finding of multiple well-differentiated papillary mesotheliomas in peritoneum.

We present a case of multiple well-differentiated papillary mesotheliomas (WDPM) in the peritoneum found incidentally in a 63-year-old man with urothelial carcinoma of the bladder. When multiple tumors are seen, malignant mesothelioma should be excluded by histopathological examination as this may have a similar focal appearance to WDPM. True stromal invasion is by far the most reliable criterion of mesothelial malignancy. In doubtful cases, a conservative diagnostic approach has been recommended. Compared to malignant mesotheliomas, WDPMs are rare and have a relatively indolent clinical course with a good prognosis. Great care is needed when diagnosing mesothelial proliferations, given the crucial nature of a benign vs malignant diagnosis. No standardized treatment has yet been established.

Transcatheter arterial embolization is the first-line therapy of choice in peptic ulcer bleeding not responding to endoscopic therapy.

OBJECTIVE: In 5-10% of patients with peptic ulcer bleeding (PUB) it is impossible to achieve endoscopic hemostasis because of severe bleeding. These patients have traditionally been treated surgically. Transcatheter arterial embolization (TAE) may, however, be associated with a better outcome because of the less-invasive nature of the procedure. The aim of the present study was to identify the treatment of choice in endoscopy-refractory PUB. MATERIALS AND METHODS: A retrospective study. Consecutive patients treated with surgery or TAE for endoscopy-refractory PUB during a period of 16 years at a university hospital were included. Primary hemostasis, rebleeding rate, mortality, and complications were assessed. Mortality was compared between groups after adjustment for age, comorbidity, and anemia using logistic regression analyses. Comorbidity was quantified using the Charlson comorbidity index (CCI). RESULTS: One hundred and eighteen patients were included. Patients treated with TAE had a higher CCI (mean: 2.33 vs 1.42; p = .003), and more severe anemia (mean: 6.8 vs 7.9 g/dl; p = .007) compared with patients treated with surgery. Surgery was associated with a higher rate of primary hemostasis (100% vs 91%; p = .007), lower rate of rebleeding (15% vs 40%; p = .004) but also higher rate of complications (60% vs 38%; p = .02) than TAE. Surgery was associated with an increased mortality (Odds ratio: 3.05; p = .033) when adjusting for confounding factors and excluding patients (n = 3) who were not candidates for both interventions. CONCLUSIONS: We propose use of TAE as first-line therapy in these patients as it may be associated with lower mortality and lower rate of complications compared with surgery.