In vivo characterization of pancreatic cystic lesions by needle-based confocal laser endomicroscopy (nCLE): proposition of a comprehensive nCLE classification confirmed by an external retrospective evaluation.

BACKGROUND AND AIMS: The differential diagnosis of solitary pancreatic cystic lesions is sometimes difficult. Needle-based confocal laser endomicroscopy (nCLE) performed during endoscopic ultrasound-fine-needle aspiration (EUS-FNA) enables real-time imaging of the internal structure of such cysts. Criteria have already been described for serous cystadenoma and intraductal papillary mucinous neoplasm (IPMN). The aims of the study were to determine new nCLE criteria for the diagnosis of pancreatic cystic lesions, to propose a comprehensive nCLE classification for the characterization of those lesions, and to carry out a first external retrospective validation . METHODS: Thirty-three patients with a lone pancreatic cystic lesion were included (CONTACT 1 study). EUS-FNA was combined with nCLE. Diagnosis was based on either pathology result (Group 1, n = 20) or an adjudication committee consensus (Group 2, n = 13). Six investigators, unblinded, studied cases from Group 1 and identified nCLE criteria for mucinous cystic neoplasm (MCN), pseudocyst (PC), and cystic neuroendocrine neoplasm (NEN). Four external reviewers assessed, blinded, the yield and interobserver agreement for the newly identified (MCN, PC) and previously described (IPMN, SC) criteria in a subset of 31 cases. RESULTS: New nCLE criteria were described for MCN (thick gray line), PC (field of bright particles), and cystic NEN (black neoplastic cells clusters with white fibrous areas). These criteria correlated with the histological features of the corresponding lesions. In the retrospective validation, a conclusive nCLE result was obtained for 74 % of the cases (87 % "true" and 13 % "false" with respect to the final diagnosis). On this limited case series, the nCLE criteria showed a trend for high diagnostic specificity (>90 % for mucinous cysts, 100 % for non-mucinous cysts). CONCLUSIONS: Based on this newly completed atlas of interpretation criteria, nCLE could facilitate the diagnosis of pancreatic cystic lesion types.

A novel approach to the diagnosis of pancreatic serous cystadenoma: needle-based confocal laser endomicroscopy.

BACKGROUND AND STUDY AIMS: The differential diagnosis of solitary pancreatic cystic lesions is frequently difficult. Needle-based confocal laser endomicroscopy (nCLE) performed during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a new technology enabling real-time imaging of the internal structure of such cysts. The aim of this pilot study was to identify and validate new diagnostic criteria on nCLE for pancreatic cystic lesions. PATIENTS AND METHODS: A total of 31 patients with a solitary pancreatic cystic lesion of unknown diagnosis were prospectively included at three centers. EUS-FNA was combined with nCLE. The final diagnosis was based on either a stringent gold standard (surgical specimen and/or positive cytopathology) or a committee consensus. Six nonblinded investigators reviewed nCLE sequences from patients with the most stringent final diagnosis, and identified a single feature that was only present in serous cystadenoma (SCA). The findings were correlated with the pathology of archived specimens. After a training session, four blinded independent observers reviewed a separate independent video set, and the yield and interobserver agreement for the criterion were assessed. RESULTS: A superficial vascular network pattern visualized on nCLE was identified as the criterion. It corresponded on pathological specimen to a dense and subepithelial capillary vascularization only seen in SCA. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of this sign for the diagnosis of SCA were 87 %, 69 %, 100 %, 100 %, and 82 %, respectively. Interobserver agreement was substantial (κ = 0.77). CONCLUSION: This new nCLE criterion seems highly specific for the diagnosis of SCA. The visualization of this criterion could have a direct impact on the management of patients by avoiding unnecessary surgery or follow-up.Clinicaltrials.gov NCT01563133.

[Basal-like breast cancer: a review]. / Le cancer du sein de phénotype basal.

Breast cancers of basal phenotype have been identified by molecular profiling and are associated with a poor prognosis. This review describes the morphological characteristics of these tumors and focuses on their profiling using immunohistochemistry: absence of detectable hormone receptors and HER2, expression of basal cytokeratins (CK5/6, CK14), myoepithelial markers (p63, smooth muscle actin) and HER1. This phenotype may be encountered in all histological types of breast cancer and is further divided into three subtypes according to prognosis and protein profiling. Pure basal and basal/myoepithelial subtypes have a poor prognosis in contrast to the myoepithelial subtype.