EUS-guided FNA of pancreatic metastases: a multicenter experience

BACKGROUND: Metastatic lesions of the pancreas are a rare but important cause of focal pancreatic lesions. The purpose of this study is to describe the EUS features, cytologic diagnoses, and clinical impact of a cohort of patients with pancreatic metastases diagnosed by EUS-guided FNA (EUS-FNA). METHODS: Over a 6-year period, in a retrospective, multicenter study, patients had the diagnosis of pancreatic metastases confirmed with EUS-FNA. All examinations were performed by one of 5 experienced endosonographers. The EUS and the clinical findings of pancreatic metastases were compared with those of a cohort with primary pancreatic malignancy. RESULTS: Thirty-seven patients with possible metastases were identified, and 13 were excluded because of diagnostic uncertainty. The remaining 24 underwent EUS-FNA (mean passes 4.1) of a pancreatic mass without complications. Diagnoses included metastases from primary kidney (10), skin (6), lung (4), colon (2), liver (1), and stomach (1) cancer. In 4 (17%), 16 (67%), and 24 (100%) patients, EUS-FNA provided the initial diagnosis of malignancy, tumor recurrence, and pancreatic metastases, respectively. Four (17%) metastases initially were discovered by EUS after negative (n = 3) or inconclusive (n = 1) CT scans. Compared with primary cancer, pancreatic metastases were more likely to have well-defined margins (46% vs. 4%) compared with irregular (94% vs. 54%; p < 0.0001) margins. No statistically significant difference between the two populations was noted for tumor size, echogenicity, consistency, location, lesion number, or number of FNA passes performed. CONCLUSIONS: Pancreatic metastases are an important cause of focal pancreatic lesions and may occasionally be discovered during EUS examination after previously negative or inconclusive CT. Use of immunocytochemistry, when available, may help to confirm a suspected diagnosis. These lesions are more likely to have well-defined EUS margins compared with primary pancreatic cancer.     

Role of preoperative endoscopic ultrasound-guided fine-needle tattooing of a pancreatic head insulinoma

Although insulinomas are rare, they are the most com-mon pancreatic neuroendocrine tumor, with an inci-dence of four cases per million population. Insulinomas are generally benign indolent intrapancreatic tumors. Surgical resection remains the main option for treat-ment. However, up to 67% of a pancreatic head insu-linomas are nonpalpable, thus surgical resection of the nonplapable insulinoma in this area could become prob-lematic resulting in prolonged surgical time, increased risk of pancreatic duct injury and need for pancreati-coduodenectomy. Endoscopic ultrasound-guided fine- needle tattooing(EUS-FNT), has been shown to have a crucial role for localization of pancreatic body and tail lesions, facilitating laparoscopic distal pancreatectomyand helping surgeons identify the location of the tumor. EUS-FNT might have a role for preoperative localiza-tion of pancreatic head insulinomas which are likely to be nonpalpable. We report a case of preoperative EUS-FNT for localization of a nonplapable pancreatic head insulinoma. This report demonstrates that EUS-FNT of pancreatic head insulinomas may facilitate surgical resection, reduce operative time and decrease surgical complications.     

Prospective study of EUS-guided tissue acquisition with a 20G core biopsy needle with a forward bevel for solid pancreatic mass

There is a growing need for tissue collection for immunostaining and genetic testing. Recently, several fine-needle biopsy needles are commercially available for endoscopic ultrasound-guided tissue acquisition.This prospective historical controlled study evaluates a 20G core biopsy needle with a forward bevel for solid pancreatic masses larger than 15 mm in diameter. The primary endpoint was the accuracy of histological diagnosis. The secondary endpoints included technical success rate, sample adequacy for histology, cytological diagnostic accuracy, and adverse events.Seventy consecutive patients were enrolled between January and October 2017. We achieved technical success in all cases regardless of the puncture sites or the endosonographer''s experience. The final diagnoses were neoplasms in 67 patients (95.7%; pancreatic cancer in 65 patients, neuroendocrine neoplasm in 1, and malignant lymphoma in 1) and benign lesions in 3 patients (4.3%; autoimmune pancreatitis in 2 patients and mass-forming pancreatitis in 1). The obtained specimens were adequate for histological evaluation in all cases and the histological accuracy was 91.4% (95% confidence interval, 82.3–96.8%, P < .05) with the sensitivity and specificity of 91.0% and 100%, respectively. The cytological diagnostic accuracy was 95.7% and all patients were accurately diagnosed by combining cytological and histological examinations. As for adverse events, an asymptomatic needle fracture occurred in 1 case (1.4%).This 20G core biopsy needle with a forward bevel showed a high accuracy of histological diagnosis for solid pancreatic masses.     

Detection of pancreatic metastases by EUS-guided fine-needle aspiration

BACKGROUND: Metastases to the pancreas are usually found incidentally. Tissue diagnosis is imperative because imaging alone is incapable of differentiating them from primary pancreatic tumors. This study tested whether it is possible to differentiate metastases from other focal pancreatic lesions by using EUS-guided fine-needle aspiration (EUS-FNA) for cytodiagnosis. METHODS: One hundred fourteen consecutive patients (mean age 61 years) with focal pancreatic masses, detected on CT, underwent EUS-FNA by using a linear-array echoendoscope and 22-gauge needles. RESULTS: Adequate specimens were obtained from 112 lesions. Carcinomas were identified in 68 cases (60.7%), 56 (50%) of pancreatic origin and 12 (10.7%) from distant primary tumors. The metastases were all located in the head and body of the pancreas and measured 1.8 to 4.0 cm. The echo-texture was heterogeneous or hypoechoic in all cases and resembled that of primary tumors. Six of the 12 patients with metastatic disease had a prior diagnosis of cancer (breast, 3; renal cell, 2; salivary gland, 1), 4 of them with a recurrence and 2 with a second carcinoma metastasizing to the pancreas. Six patients without a prior diagnosis of cancer had metastases from renal cell, colonic, ovarian, and esophageal carcinomas; one metastasis was from an unknown primary and another was from a malignant lymphoma. These findings influenced the therapeutic strategy in 8 patients who underwent nonsurgical palliation. There were no complications. CONCLUSIONS: Pancreatic metastasis is an important cause of focal pancreatic lesions, but the EUS features are not diagnostic. Simultaneous EUS-FNA allows cytodiagnosis and can have a decisive influence on the selection of appropriate therapeutic strategies.