Masato Takamatsu

Intraductal carcinoma with complex fusion of tubular glands without macroscopic mucus in main pancreatic duct: Dilemma in classification

An 84‐year‐old man, who was being followed up after lobectomy for lung carcinoma, was referred for evaluation of a dilated main pancreatic duct (MPD) from the body to the tail. Endoscopic ultrasonography demonstrated a low‐echo mass occupying the MPD from the body to the tail. Endoscopic retrograde pancreatography showed an occlusion of the MPD in the body, and brush cytology indicated malignant cells. Distal pancreatectomy was performed. Grossly, a white–yellow, irregular‐shaped solid mass without macroscopic mucus filled the lumen of the MPD. Histologically, the mass consisted of a complex fusion of tubular glands with atypical nuclei, which did not have intracellular mucus and oncocytic cytoplasm. The tumor mass showed abrupt transition to the normal epithelium. Immunohistochemically the tumor cells were partially positive for mucin 1 (MUC1) and MUC6, and negative for MUC2, MUC5AC, and lipase. Unfortunately the patient died of brain metastasis from lung carcinoma 15 months later. A review of reported cases of intraductal tubular tumors of the pancreas showed that the present case involved characteristics and immunohistochemical staining pattern similar to those of intraductal tubular carcinoma, although it might not be described as a typical intraductal tubular carcinoma under the existing Japanese rules.

Impact of changing our cannulation method on the incidence of post-endoscopic retrograde cholangiopancreatography pancreatitis after pancreatic guidewire placement

AIM To clarify whether the incidence of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) after pancreatic guidewire placement (PGW) can be reduced by using a different cannulation method. METHODS Between April 2001 and October 2009, PGW was performed in 142 patients with native papilla to overcome difficult biliary cannulation. Our cannulation method for ERCP was changed from contrast injection (CI) using a single-lumen catheter (April 2001-May 2008) to wire-guided cannulation (WGC) using a double-lumen catheter (June 2008-October 2009). The CI protocol was also changed during the study period: in the first period it was used for routine pancreatography for detecting small pancreatic cancer (April 2001-November 2002), whereas in the second period it was not (December 2002-May 2008). In PGW with CI using a single-lumen catheter, the contrast medium in the catheter lumen was injected into the pancreatic duct. The success rate of biliary cannulation, the incidence of PEP according to the cannulation method, and the impact of CI using a single-lumen catheter on PEP in comparison with WGC using a double-lumen catheter were investigated. RESULTS CI with routine pancreatography, CI without routine pancreatography, and WGC were performed in 27 patients, 77 patients and 38 patients, respectively. Routine pancreatography did not contribute to the early diagnosis of pancreatic cancer in our study period. In CI without routine pancreatography and WGC, diagnostic pancreatography was performed in 17 patients and no patients, respectively. The success rate of biliary cannulation by PGW alone was 69%, and the final success rate was increased to 80.3% by the addition of consecutive maneuvers or a second ERCP. PEP occurred in 22 patients (15.5%), and the severity was mild in all cases. When analyzed according to cannulation method, the incidence of PEP was 37.0% (10/27) in the patients who underwent CI with routine pancreatography, 14.3% (11/77) in those who underwent CI without routine pancreatography, and 2.6% (1/38) in those who underwent WGC. In all patients who underwent CI using a single-lumen catheter, the incidence of PEP was 20% (21/104), which was significantly higher than that in WGC using a double-lumen catheter. In univariate and multivariate analysis, CI using a single-lumen catheter showed a high, statistically significant, odds ratio for PEP after PGW. CONCLUSION The practice of a cannulation method involving the use of a double-lumen catheter minimizes the CI dose administered to the pancreatic duct and reduces the incidence of PEP after PGW.

Endoscopic ultrasound-guided antegrade stone removal in a patient with pancreatic stones and anastomotic stricture after end-to-side pancreaticojejunostomy

Pancreaticoenteric anastomotic stricture can occur as a late complication of pancreatic head resection and is difficult to manage. The surgically altered anatomies of patients that have undergone pancreatic head resection make it difficult to perform pancreatic duct drainage using conventional endoscopes, and it is especially difficult to endoscopically identify stenotic pancreaticojejunal anastomoses. A 40-year-old woman was referred to our department for the treatment of symptomatic multiple pancreatic stones and anastomotic stricture after end-to-side pancreaticojejunostomy. Endoscopic ultrasound-guided pancreaticogastrostomy was performed in an attempt to avoid re-surgery. At 18 days after the initial procedure, a guidewire was successfully placed in the jejunum through the anastomotic stricture. The anastomotic stricture was dilated using a dilation balloon, and all of the stones were pushed into the jejunum using a retrieval balloon. No complications were experienced during the procedure. At 22 months after the stone removal, the main pancreatic duct displayed a decreased diameter, and no stone recurrence was detected.

Obstructive jaundice caused by a portal cavernoma

A 69-year-old Japanese man was admitted to our hospital because of acute cholangitis with biliary obstruction. The cause of obstruction was either compression by a portal cavernoma or cavernous transformation. Multidetector row computed tomography (MDCT) and abdominal ultrasonography (US) revealed a portal cavernoma around the common bile duct. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiography (ERC) demonstrated characteristic short, smooth narrowing of the bile duct. Endoscopic US and intraductal US demonstrated collateral vessels around the bile duct and were helpful for ruling out a neoplastic lesion. Thus, a combination of imaging modalities was useful for diagnosing this hepatobiliary complication, portal biliopathy.

Mucinous cystadenoma of the pancreas with huge mural hematoma

A 60‐year‐old woman was referred for evaluation of a cystic mass in the pancreatic body that extended to the tail. Transabdominal ultrasonography demonstrated an oval cystic mass 24 cm in diameter, filled with debris. On the cyst wall there was a wide‐based, smooth‐surfaced, heterogeneous high‐echoic protrusion that was 5 cm in diameter. On CT the protrusion showed internal enhancement. Endoscopic pancreatography showed no intraductal mucin or communication with the cyst. A distal pancreatectomy was performed under the diagnosis of mucinous cystadenocarcinoma. Grossly there was a brownish, hemispherical protrusion into the thin monolocular cyst. The cut surface of the protrusion showed a peripheral yellow‐brownish area and an internal wine‐colored area. Histopathologically the cyst wall consisted of tall columnar cells without atypical nuclei, ovarian‐type stroma beneath the epithelium, and fibrotic tissue with abundant capillary vessels, suggestive of a mucinous cystadenoma. The protrusion was composed of peripheral organized hematoma without a covering epithelium, and internal hemorrhage and many capillary vessels, with no evidence of tumor cell necrosis. These histopathological findings appear to be similar to those of chronic expanding hematoma. The formation of a huge mural hematoma in a mucinous cystic neoplasm can occur as a repair process after the breaking of intrawall vessels.

A Case of Non-Alcoholic Pancreatitis Treated with Steroid Followed-up Using Intraductal Ultrasonography and Endoscopic Retrograde Pancreatography

A 42‐year‐old man with jaundice was found to have a pancreatic mass in the head by ultrasonography. Endoscopic retrograde cholangiopancreatography (ERCP) showed a segmental narrowing of the main pancreatic duct (MPD) with a mild upstream dilatation and an extrinsic stenosis of the inferior common bile duct (CBD). lntraductal ultrasonography (IDUS) showed a diffuse hypoechoic area with echogenic spots surrounding the narrowed MPD and the stenotic CBD. He was suspected of having autoimmune pancreatitis because of a characteristic pancreatogram, and 30 mg/day predniso‐lone was started. Two weeks later, the narrowing of the MPD and the stenosis of the CBD improved dramatically. But the hypoechoic area remained separate from the MPD with a fine reticular pattern on the inside. It completely disappeared in the eighth week. The diachronic changes in the IDUS were characteristic in that the hypoechoic area, which initially surrounded the MPD, disappeared near the MPD, followed by a distant area. This might explain the discrepancy between the images of ERCP and IDUS in the second week of steroid therapy.

ENDOSCOPIC NECROSECTOMY UNDER DIRECT VISION AFTER ENDOSCOPIC ULTRASOUND-GUIDED CYSTGASTROSTOMY FOR ORGANIZED PANCREATIC NECROSIS

A 56‐year‐old man was referred for an enlarging pancreatic pseudocyst that developed after severe acute pancreatitis with gallstones. Abdominal ultrasound showed a huge cystic lesion with a large amount of solid high echoic components. Arterial phase contrast‐enhanced computed tomography scan revealed arteries across the cystic cavity. Stents were placed after endoscopic ultrasound‐guided cystgastrostomy; however, the stents were obstructed by necrotic debris, and secondary infection of the pseudocyst occurred. Therefore, the cystgastrostomy was dilated by a dilation balloon, and a forward‐viewing endoscope was inserted into the cystic cavity. Many vessels and a large amount of necrotic debris existed in the cavity. Under direct vision, all necrotic debris was safely removed using a retrieval net and forceps. One year after this procedure, there was no recurrence. Our case indicates that peripancreatic fat necrosis can cause exposure of vessels across/along the cystic cavity, and blind necrosectomy should be avoided.