EUS-guided reverse bevel fine-needle biopsy sampling and open tip fine-needle aspiration in solid pancreatic lesions - a prospective, comparative study.

OBJECTIVES: Different diagnostic entities can present as solid pancreatic lesions (SPL). This study aimed to explore the utility of endoscopic ultrasound-guided reverse bevel fine-needle biopsy sampling (EUS-FNB) in SPLs. MATERIAL AND METHODS: In 2012-2015, consecutive patients with SPLs were prospectively included in a tertiary center setting and subjected to dual needle sampling with a 22 gauge reverse bevel biopsy needle and a conventional 25 gauge open tip aspiration needle (EUS-FNA). The outcome measures were the diagnostic accuracy of sampling, calculated for each modality separately and for the modalities combined (EUS-FNA + FNB), and the adverse event rate related to sampling. RESULTS: In 68 unique study subjects, the most common diagnostic entities were pancreatic neuroendocrine tumor, PNET, (34%), pancreatic ductal adenocarcinoma, PDAC, (32%), pancreatitis (15%) and metastasis (6%). The overall diagnostic accuracy of EUS-FNB was not significantly different from that of EUS-FNA, (69% vs. 78%, p = .31). EUS-FNA + FNB, compared with EUS-FNA alone, had a higher sensitivity for tumors other than PDAC (89% vs. 69%, p = .02) but not for PDACs (95% vs. 85%, p = .5). No adverse event was recorded after the study dual-needle sampling procedures. CONCLUSIONS: Endoscopic ultrasound-guided tissue acquisition performed with a 22 gauge reverse bevel biopsy needle is safe but not superior to conventional fine-needle aspiration performed with a 25 gauge open tip needle in diagnosing solid pancreatic lesions. However, the performance of both these modalities may facilitate the diagnostic work-up in selected patients, such as cases suspicious for pancreatic neuroendocrine tumors and metastases. NCT02360839.

Mutational Signature and Transcriptomic Classification Analyses as the Decisive Diagnostic Tools for a Cancer of Unknown Primary.

PURPOSE: Cancer of unknown primary is a group of metastatic tumors in which the standard diagnostic workup fails to identify the site of origin of the tumor. The potential impact of precision oncology on this group of patients is large, because actionable driver mutations and a correct diagnosis could provide treatment options otherwise not available for patients with these fatal cancers. This study investigated if comprehensive genomic analyses could provide information on the origin of the tumor. PATIENTS AND METHODS: Here we describe a patient whose tumor was misdiagnosed at least three times. Next-generation sequencing, a patient-derived xenograft mouse model, and bioinformatics were used to identify an actionable mutation, predict resistance development to the targeted therapy, and correctly diagnose the origin of the tumor. Transcriptomic classification was benchmarked using The Cancer Genome Atlas (TCGA). RESULTS: Despite the lack of a known primary tumor site and the absence of diagnostic immunohistochemical markers, the origin of the patient's tumor was established using the novel bioinformatic workflow. This included a mutational signature analysis of the sequenced metastases and comparison of their transcriptomic profiles to a pan-cancer panel of tumors from TCGA. We further discuss the strengths and limitations of the latter approaches in the context of three potentially incorrectly diagnosed TCGA lung tumors. CONCLUSION: Comprehensive genomic analyses can provide information on the origin of tumors in patients with cancer of unknown primary.

High clinical impact and diagnostic accuracy of EUS-guided biopsy sampling of subepithelial lesions: a prospective, comparative study.

BACKGROUND: In a tertiary center setting we aimed to study the diagnostic accuracy and clinical impact of EUS-guided biopsy sampling (EUS-FNB) with a reverse bevel needle compared with that of fine needle aspiration (EUS-FNA) in the work-up of subepithelial lesions (SEL). METHODS: All patients presenting with SELs referred for EUS-guided sampling were prospectively included in 2012-2015. After randomization of the first pass modality, dual sampling with both EUS-FNB and EUS-FNA was performed in each lesion. Outcome measures in an intention-to-diagnose analysis were the diagnostic accuracy, technical failures, and adverse events. The clinical impact was measured as the performance of additional diagnostic procedures post-EUS and the rate of unwarranted resections compared with a reference cohort of SELs sampled in the same institution 2006-2011. RESULTS: In 70 dual sampling procedures of unique lesions (size: 6-220 mm) the diagnostic sensitivity for malignancy and the overall accuracy of EUS-FNB was superior to EUS-FNA compared head-to-head (90 vs 52%, and 83 vs 49%, both p < 0.001). The adverse event rate of EUS-FNB was low (1.2%). EUS-FNB in 2012-2015 had a positive clinical impact in comparison with the reference cohort demonstrated by less cases referred for an additional diagnostic procedure, 12/83 (14%) vs 39/73 (53%), p < 0.001, and fewer unwarranted resections in cases subjected to surgery, 3/48 (6%) vs 12/35 (34%), p = 0.001. CONCLUSIONS: EUS-FNB with a reverse bevel needle is safe and superior to EUS-FNA in providing a conclusive diagnosis of subepithelial lesions. This biopsy sampling approach facilitates a rational clinical management and accurate treatment.

Characterizing gastrointestinal stromal tumors and evaluating neoadjuvant imatinib by sequencing of endoscopic ultrasound-biopsies.

AIM: To evaluate endoscopic ultrasound (EUS)-guided biopsies for the pretreatment characterization of gastrointestinal stromal tumors (GIST) to personalize the management of patients. METHODS: All patients with lesions suspected to be GIST who were referred for EUS-sampling at a tertiary Swedish center were eligible for inclusion 2006-2015. During the observational study phase (2006-2011), routine fine-needle-aspiration (EUS-FNA) was performed. In 2012-2015, we converted to an interventional, randomized protocol with dual sampling EUS-FNA and fine-needle-biopsy-sampling (EUS-FNB) for all lesions. c-KIT- and DOG-1-immunostaining was attempted in all samples and a manual count of the Ki-67-index was performed. FNB-sampled tissue and the resected specimens were subjected to Sanger sequencing of the KIT and platelet-derived growth factor alpha (PDGFRA) genes. RESULTS: In all, 64 unique patients with GIST were included, and of these, 38 were subjected to pretreatment dual sampling. EUS-FNB had a higher diagnostic sensitivity when compared head-to-head with EUS-FNA (98% vs 58%, P < 0.001) and was more adequate for Ki-67-indexing (Ki-67EUS) (92% vs 40%, P < 0.001). Sequencing of EUS-biopsies was successful in 43/44 (98%) patients, and the mutation profiles (KIT-mutation 73%, PDGFRA-mutation 18%, wild-type 7%) were fully congruent with those detected in the corresponding resected specimens. In imatinib-naïve patients, the Ki-67EUS was comparable with the Ki-67-index in the corresponding surgical specimens (Ki-67SURG) (2.7% vs 2.9%, P = 0.68). In patients treated with neoadjuvant imatinib who also carried mutations indicating sensitivity, the Ki-67EUS was higher than the Ki-67SURG (2.5% vs 0.2%, P = 0.005), with a significant reduction in the Ki-67-index of -91.5% (95%CI: -82.4 to -96.0, P = 0.005). CONCLUSION: EUS-guided biopsy sampling is accurate for the pretreatment diagnosis and characterization of GISTs and allows the prediction and evaluation of tumor response to neoadjuvant imatinib therapy.

A case of large mucinous adenocarcinoma arising in a long-standing fistula-in-ano.

BACKGROUND: Chronic anal fistulas are not rare conditions, however, the development of a carcinoma in a long-standing fistula-in-ano is rare. METHODS: The case of a 77-year-old male with a large perianal mucinous adenocarcinoma arising in a long-standing fistula-in-ano is presented. RESULTS: Perianal biopsy revealed mucinous adenocarcinoma. Abdominal CT, double contrast barium examination and flexible sigmoidoscopy revealed no other tumoral lesion in the colon and rectum. CONCLUSION: The patient underwent abdominoperineal resection including wide tumor excision on the gluteal region. The final reconstruction was performed by bilateral gracilis musculocutaneous flaps. Due to clinical and histopathological evidence it was thought that a curative resection had been performed. To date he is clinically disease free.