FAP expression in alpha cells of Langherhans insulae-implications for FAPI radiopharmaceuticals' use.

PURPOSE: Radiopharmaceuticals targeting fibroblast activation protein (FAP) alpha are increasingly studied for diagnostic and therapeutic applications. We discovered FAP expression at immunohistochemistry (IHC) in the alpha cells of the Langerhans insulae of few patients. Therefore, we planned an investigation aimed at describing FAP expression in the pancreas and discussing the implications for radioligand applications. METHODS: We retrospectively included 40 patients from 2 institutions (20 pts each) according to the following inclusion/exclusion criteria: (i) pathology proven pancreatic ductal adenocarcinoma and neuroendocrine tumors (NET), 10 pts per each group at each center; (ii) and availability of paraffin-embedded tissue; and (iii) clinical-pathological records. We performed IHC analysis and applied a semiquantitative visual scoring system (0, negative staining; 1, present in less than 30%; 2, present in more than 30% of the area). FAP expression was assessed according to histology-NET (n = 20) vs ductal adenocarcinoma (n = 20)-and to previous treatments within the adenocarcinoma group. The local ethics committee approved the study (No. INT 21/16, 28 January 2016). RESULTS: The population consisted of 24 males and 16 females, with a median age of 68 and a range of 14-84 years; 8/20 adenocarcinoma patients received chemotherapy. In all the Langerhans insulae (40/40), pancreatic alpha cells were found to express FAP, with a score of 2. No difference was found among NET (20/20) and adenocarcinoma (20/20), nor according to neoadjuvant chemotherapy in the adenocarcinoma cohort (received or not received). CONCLUSION: Pancreatic Langerhans islet alpha cells normally express FAP. This is not expected to influence the diagnostic accuracy of FAP-targeting tracers. In the therapeutic setting, our results suggest the need to better elucidate FAPI radioligands' effects on the Langerhans insulae function.

Invasive IPMN relapse later and more often in lungs in comparison to pancreatic ductal adenocarcinoma.

BACKGROUND: The different oncological outcomes of invasive intraductal papillary mucinous neoplasm (I-IPMN) and pancreatic ductal adenocarcinoma (PDAC) are debated. This study aimed to compare disease recurrence patterns and histopathological characteristics in patients with resected I-IPMN and PDAC. METHODS: Consecutive patients undergoing surgical resection for stage I-III I-IPMN or PDAC between 2010 and 2016 were retrospectively analyzed. Patients treated with neoadjuvant therapy or resected for Tis neoplasia were excluded. All surgical specimens were re-staged according to AJCC-8th-edition. RESULTS: A total of 330 patients were included, of whom 43 had I-IPMN and 287 had PDAC. Median follow-up time was 26.7 (1.3-92.3) months and estimated median disease-free survival (DFS) was 60.3 months (47.2-73.4) for I-IPMN and 23.8 (19.3-28.2) months for PDAC (p < 0.001). During follow-up, 32.6% of I-IPMN and 67.9% of PDAC patients experienced recurrence (p < 0.001). The sites of first recurrence were the lungs (38.5% vs 13.1%, p = 0.027), liver (28.6% vs 45.0%, p = 0.180) and local (15.4% vs 36.6%, p = 0.101) for I-IPMN and PDAC, respectively. At multivariate analysis, I-IPMN histology remained an independent predictive factor for longer DFS (OR 0.528, CI 95% 0.278-1.000, p = 0.050), regardless of stage or adjuvant chemotherapy. I-IPMN and PDAC differed in rates of neuroinvasion (51.2% vs 97.2%) and positive lymph node status (N+) (46.5% vs 82.7%), especially in patients with lower T status. CONCLUSION: I-IPMN showed a different recurrence pattern compared to PDAC, with a higher lung tropism, and longer DFS. This different biological behavior is associated with lower rates of neuroinvasion and nodal involvement, especially in early-stage disease.

Digital Pathology During the COVID-19 Outbreak in Italy: Survey Study.

BACKGROUND: Transition to digital pathology usually takes months or years to be completed. We were familiarizing ourselves with digital pathology solutions at the time when the COVID-19 outbreak forced us to embark on an abrupt transition to digital pathology. OBJECTIVE: The aim of this study was to quantitatively describe how the abrupt transition to digital pathology might affect the quality of diagnoses, model possible causes by probabilistic modeling, and qualitatively gauge the perception of this abrupt transition. METHODS: A total of 17 pathologists and residents participated in this study; these participants reviewed 25 additional test cases from the archives and completed a final psychologic survey. For each case, participants performed several different diagnostic tasks, and their results were recorded and compared with the original diagnoses performed using the gold standard method (ie, conventional microscopy). We performed Bayesian data analysis with probabilistic modeling. RESULTS: The overall analysis, comprising 1345 different items, resulted in a 9% (117/1345) error rate in using digital slides. The task of differentiating a neoplastic process from a nonneoplastic one accounted for an error rate of 10.7% (42/392), whereas the distinction of a malignant process from a benign one accounted for an error rate of 4.2% (11/258). Apart from residents, senior pathologists generated most discrepancies (7.9%, 13/164). Our model showed that these differences among career levels persisted even after adjusting for other factors. CONCLUSIONS: Our findings are in line with previous findings, emphasizing that the duration of transition (ie, lengthy or abrupt) might not influence the diagnostic performance. Moreover, our findings highlight that senior pathologists may be limited by a digital gap, which may negatively affect their performance with digital pathology. These results can guide the process of digital transition in the field of pathology.

Prospective Evaluation of Intrahepatic Microscopic Occult Tumor Foci in Patients with Numerous Colorectal Liver Metastases.

BACKGROUND: Patients with numerous colorectal liver metastases (CLM) have high risk of early recurrence after liver resection (LR). The presence of intrahepatic occult microscopic metastases missed by imaging has been hypothesized, but it has never been assessed by pathology analyses. METHODS: All patients with > 10 CLM who underwent LR between September 2015 and September 2016 were considered. A large sample of liver without evidence of disease ("healthy liver") was taken from the resected specimen and sent to the pathologist. One mm-thick sections were analyzed. Any metastasis, undetected by preoperative and intraoperative imaging, but identified by the pathologist was classified as occult microscopic metastasis. RESULTS: Ten patients were prospectively enrolled (median number of CLM n = 15). In a per-lesion analysis, the sensitivity of computed tomography and magnetic resonance imaging was 91 and 98% respectively. The pathology examination confirmed all the CLM. All patients had an adequate sample of "healthy liver" (median number of examined blocks per sample n = 14 [5-33]). No occult microscopic metastases were detected. After a median follow-up of 15 months, 5 patients were disease-free. Recurrence was hepatic and bilobar in all patients. CONCLUSIONS: Clinically relevant occult microscopic disease in patients with numerous CLM is excluded. These results support the indication to resection in such patients and exclude the need for de principe major hepatectomy to increase the completeness of surgery.

No detectable truncating mutations in large T antigen (LT-Ag) sequence of Merkel cell polyomavirus (MCPyV) DNA obtained from porocarcinomas.

Merkel cell polyomavirus (MCPyV) is associated with Merkel cell carcinoma (MCC). In tumor cells the MCPyV large T antigen (LT-Ag) is frequently found truncated and this is considered a major tumor-specific signature. The role of MCPyV in other, non-MCC tumours, is little known. Viral DNA and/or tumour-specific mutations have been sometimes detected in different tumours, but such data are not unequivocal and the involvement of the virus in the tumorigenesis is not clear. In a previous study, we demonstrated a significantly higher prevalence of MCPyV DNA in formalin fixed paraffin embedded (FFPE) porocarcinoma tissues compared to the normal skin. In the present study, we investigated the presence of truncating mutations in MCPyV LT-Ag coding region in porocarcinoma specimens. Using several overlapped PCR primer pairs, the complete LT-Ag sequence from two biopsies were obtained. No truncating mutations were detected. The lack of truncating mutations in LT-Ag sequence does not seem to support the role of MCPyV in porocarcinoma oncogenesis. However, an oncogenetic mechanism, different from that proposed for MCC and not associated with the LT-Ag mutations/deletions, cannot be excluded. Further studies of more sequences coding for LT-Ag would be needed to verify this hypothesis.

Exploring a novel composite method using non-contrast EUS enhanced microvascular imaging and cyst fluid analysis to differentiate pancreatic cystic lesions.

BACKGROUND AND AIMS: Differentiating pancreatic cystic lesions (PCLs) remains a diagnostic challenge. The use of high-definition imaging modalities which detect tumor microvasculature have been described in solid lesions. We aim to evaluate the usefulness of cystic microvasculature when used in combination with cyst fluid biochemistry to differentiate PCLs. METHODS: We retrospectively analyzed 110 consecutive patients with PCLs from 2 Italian Hospitals who underwent EUS with H-Flow and EUS fine needle aspiration to obtain cystic fluid. The accuracy of fluid biomarkers was evaluated against morphological features on radiology and EUS. Gold standard for diagnosis was surgical resection. A clinical and radiological follow up was applied in those patients who were not resected because not surgical indication and no signs of malignancy were shown. RESULTS: Of 110 patients, 65 were diagnosed with a mucinous cyst, 41 with a non-mucinous cyst, and 4 with an undetermined cyst. Fluid analysis alone yielded 76.7% sensitivity, 56.7% specificity, 77.8 positive predictive value (PPV), 55.3 negative predictive value (NPV) and 56% accuracy in diagnosing pancreatic cysts alone. Our composite method yielded 97.3% sensitivity, 77.1% specificity, 90.1% PPV, 93.1% NPV, 73.2% accuracy. CONCLUSIONS: This new composite could be applied to the holistic approach of combining cyst morphology, vascularity, and fluid analysis alongside endoscopist expertise.

Histological Scores in Patients with Inflammatory Bowel Diseases: The State of the Art.

The histological assessment has been advocated as a detailed and accurate measure of disease activity in inflammatory bowel diseases (IBD). In ulcerative colitis (UC), histological activity has been demonstrated to be associated with higher rates of relapse, prolonged corticosteroid use and long-term complications, even when endoscopic remission is achieved. Therefore, histological healing may represent a potential treatment target. Several histological scores have been developed and are available today. The Robarts histopathology index (RHI) and the Nancy index (NI) are the only two recommended by the European Crohn's and Colitis Organization (ECCO) for use in patients with UC. Conversely, in Crohn's disease (CD), the discontinuous nature of lesions has limited standardized histological assessment. Most of the available histological scoring systems in CD are complex and not validated. The aim of this review is to comprehensively summarize the latest evidence regarding histological scoring systems in IBD. We guide the reader through understanding the importance of an accurate microscopic evaluation using validated scoring systems, highlighting the strengths and pitfalls of each score. The priorities of future research needs are also addressed.

Pancreatic ductal adenocarcinoma and invasive intraductal papillary mucinous tumor: Different prognostic factors for different overall survival.

BACKGROUND: It is unclear whether invasive intraductal papillary mucinous neoplasm (IPMN) has different clinical and prognostic characteristics, beyond histological factors, when compared to pancreatic ductal adenocarcinoma (PDAC). AIMS: compare prognostic features of resected PDAC and invasive IPMN METHODS: A retrospective study of patients resected for PDAC or invasive IPMN realized at Humanitas Cancer Center's Pancreatic Surgery Unit, Milan, Italy, between 2010 and 2016. Data recorded included patient demographics, onset symptoms, preoperative health status, tumor features, histology and surgical characteristics. Overall survival was estimated using Kaplan-Meier and prognostic factors for survival were assessed by multivariate Cox regression. RESULTS: A total of 332 patients were included (PDAC, n = 289; invasive IPMN, n = 43). Patients with invasive IPMN had better overall survival than PDAC patients (median: 76.6 versus 25.6 months; 5-year OS rate: 65.4% vs. 14.2%; p < 0.001). PDAC histology was associated with a significantly higher risk of death than IPMN (hazard ratio 1.815, 95% CI: 1.02, 3.24; p = 0.044). Survival was also worse with PDAC in early-stage disease (IA-IB-IIA, N0). In multivariate analysis, independent predictors of worse survival included perineural invasion, preoperative ASA physical status ≥3 and pain at diagnosis. CONCLUSIONS: Patients with IPMN had a better prognosis than PDAC patients, regardless of disease stage.

Clinical Application of a Real-Time Telepathology System for Frozen Section Diagnosis in Comparison With Optical Microscope.

Background: The imbalance between the increasing demand of highly specialized service and the reduction of specialists able to release this service is a global challenge for Pathology. This situation applies also to the setting of intra-operatory diagnostic: here the broad presence of Surgical divisions contrasts with the contraction of Pathology departments, progressively concentrated in few hospitals. The use of e-pathology device, such as remote-control microscopes, offers a possible solution to this imbalance. Aim: To prove the non-inferiority of function of a remote-control, real-time microscope named Nano-Eye Device (NED) with the optical microscope (OM) for intra-operatory histological diagnosis. Methods: The study was designed into two phases: discovery and validation. During the discovery phase features influencing the process of adaptation to NED were investigated in detail, focusing on the turnaround time (TAT). Validation phase investigated the diagnostic concordance between NED and OM; as well as sensitivity, specificity, and accuracy of NED in intra-operatory histological diagnosis. Results: During the discovery phase 250 cases were examined. TAT of NED was longer than that of OM (112 ± 89.8 vs. 36 ± 37.9 s) and influenced by the difficulty of the specimen, age of pathologist and the type of the specimen. In the validation phase (185 cases) TAT of NED reduced significantly to 92 ± 86.3 s (p: 0.01). NED showed a concordance rate of 98% with OM; the sensitivity (95.65%), specificity (100%), and diagnostic accuracy (98.87%) of NED were equal to that of OM. NED failed to work in 6% during the discovery phase and 4% in the validation. Conclusions: Taken as a whole, the functionality of NED is comparable to OM. It can be the alternative choice for hospital lacking on-site pathology services and one of the tool of e-pathology.

Droplet digital PCR (ddPCR) vs quantitative real-time PCR (qPCR) approach for detection and quantification of Merkel cell polyomavirus (MCPyV) DNA in formalin fixed paraffin embedded (FFPE) cutaneous biopsies.

BACKGROUND: Merkel cell polyomavirus (MCPyV) is associated with Merkel cell carcinoma and high viral load in the skin was proposed as a risk factor for the occurrence of this tumour. MCPyV DNA was detected, with lower frequency, in different skin cancers but since the viral load was usually low, the real prevalence of viral DNA could be underestimated. OBJECTIVE: To evaluate the performance of two assays (qPCR and ddPCR) for MCPyV detection and quantification in formalin fixed paraffin embedded (FFPE) tissue samples. METHODS: Both assays were designed to simultaneous detection and quantification of both MCPyV as well as house-keeping DNA in clinical samples. The performance of MCPyV quantification was investigated using serial dilutions of cloned target DNA. We also evaluated the applicability of both tests for the analysis of 76 FFPE cutaneous biopsies. RESULTS: The two approaches resulted equivalent with regard to the reproducibility and repeatability and showed a high degree of linearity in the dynamic range tested in the present study. Moreover, qPCR was able to quantify ≥105 copies per reaction, while the upper limit of ddPCR was 104 copies. There was not significant difference between viral load measured by the two methods The detection limit of both tests was 0,15 copies per reaction, however, the number of positive samples obtained by ddPCR was higher than that obtained by qPCR (45% and 37% respectively). CONCLUSIONS: The ddPCR represents a better method for detection of MCPyV in FFPE biopsies, mostly these containing low copies number of viral genome.

Detection of Merkel cell polyomavirus and human papillomavirus DNA in porocarcinoma.

BACKGROUND: Increasing evidences support the role of Merkel cell polyomavirus (MCPyV) and human papillomavirus (HPV) in non-cutaneous and cutaneous tumours. Porocarcinoma is a rare malignant neoplasm that arises from the intraepidermal ductal portion of the eccrine sweat glands. The aetiology of porocarcinoma is largely unknown and no systematic studies have been done to investigate the implication of infectious agents in the pathogenesis of this tumour. OBJECTIVES: To investigate the possible association between MCPyV and/or HPV infection and porocarcinoma. STUDY DESIGN: Forty-four formalin-fixed paraffin-embedded (FFPE) porocarcinomas (40 primary and 4 metastatic) and 10 healthy skin specimens (controls), were analysed for the presence of MCPyV and HPV DNA using molecular detection methods. RESULTS: MCPyV DNA was found in 27/40 (68%) primary porocarcinomas and in 3/10 (30%) controls (Fisher exact test: p<0.04). No significant difference in viral load was observed between tumours and healthy skin. Moreover, 2/40 primary porocarcinomas tested positive for high-risk HPV16. Cutaneous beta-HPV infection was detected in 16/40 (40%) porocarcinomas and in 6/10 (60%) controls. No particular beta-HPV types were significantly associated with tumour or with healthy skin. Two out of 4 metastatic biopsies were MCPyV DNA positive. All metastatic samples had mixed infections with cutaneous HPV types. CONCLUSIONS: This study demonstrated a significantly high prevalence of MCPyV and the presence of a broad spectrum of HPV types in porocarcinoma and provided the first available data about viral infections in this tumour. To understand the role, if any, of viral infections in the pathogenesis of porocarcinoma further studies are needed.