The Proportional Odds Model for Assessing Rater Agreement with Multiple Modalities

In this paper, we develop a model for evaluating an ordinal rating systems where we assume that the true underlying disease state is continuous in nature. Our approach in motivated by a dataset with 35 microscopic slides with 35 representative duct lesions of the pancreas. Each of the slides was evaluated by eight raters using two novel rating systems (PanIN illustrations and PanIN nomenclature),where each rater used each systems to rate the slide with slide identity masked between evaluations. We find that the two methods perform equally well but that differentiation of higher grade lesions is more consistent across raters than differentiation across raters for lower grade lesions. A proportional odds model is assumed, which allows us to estimate rater-specific thresholds for comparing agreement. In this situation where we have two methods of rating, we can determine whether the two methods have the same thresholds and whether or not raters perform equivalently across methods. Unlike some other model-based approaches for measuring agreement, we focus on the interpretation of the model parameters and their scientific relevance. We compare posterior estimates of rater-specific parameters across raters to see if they are implementing the intended rating system in the same manner. Estimated standard deviation distributions are used to make inferences as to whether raters are consistent and whether there are differences in rating behaviors in the two rating systems under comparison

Colonic Endometriosis Mimicking Colon Cancer on a Virtual Colonoscopy Study: A Potential Pitfall in Diagnosis

Colonic endometriosis has been reported in the literature to mimic colon cancer. Patients can present with symptoms almost identical to colon cancer. We present an exemplary case of a woman who was found to have a mass on conventional colonoscopy. Virtual colonoscopy was instrumental in characterizing the obstructive sigmoid mass. A biopsy of the mass revealed sigmoid endometriosis

Surgical management of giant Brunner's gland hamartoma: case report and literature review

Brunner's gland hamartomas (BGH) are uncommon benign tumors of the duodenum forming mature Brunner's glands. We report here an unusual case of a giant BGH that was not amenable to endoscopic or surgical local resection thus requiring a pancreaticoduodenectomy for extirpation. The relevant literature is discussed

Glomus Tumor of the Stomach: Depiction by Multidetector CT and Three-Dimensional Volume Rendering Imaging

Glomus tumors are uncommon tumors which can occur anywhere within the gastrointestinal tract but have been shown to occur most commonly in the gastric antrum. On CT, these tumors demonstrate hyperenhancement which may help distinguish them from other gastric masses

Autoimmune Pancreatitis Accompanied by Cholecystitis, Periaortitis and Pseudotumors of the Liver

A variety of extrapancreatic lesions have been associated with autoimmune pancreatitis (AIP), and these lesions can be difficult to diagnose. We report a patient referred to Shizuoka Cancer Center with the diagnosis of a possible biliary carcinoma with liver metastasis who was shown to have AIP accompanied by pseudotumors of liver. Clinical imaging revealed diffuse enlargement of the head of the pancreas with irregular narrowing of the main pancreatic duct and inferior common bile duct, multiple liver masses, mediastinal lymphadenopathy, and thickening of the wall of the gallbladder and abdominal aorta. Cytology and biopsy from the pancreaticobiliary tract was negative for malignancy. Serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA19-9) levels were in the normal range, but soluble interleukin 2 receptor (sIL2R), IgG4 and antinuclear antibody were abnormally high (sIL2R: 2,550 U/ml; IgG4: 764 mg/dl). Corticosteroid therapy was effective and these abnormal findings all improved. This case demonstrates the clinical importance of AIP accompanied by other systemic disorders in the differential diagnosis of patients with a pancreatic mass lesion

Diagnosis and Management of Cystic Lesions of the Pancreas

Pancreatic cysts are challenging lesions to diagnose and to treat. Determining which of the five most common diagnoses—pancreatic pseudocyst, serous cystic neoplasm (SCN), solid pseudopapillary neoplasm (SPN), mucinous cystic neoplasm (MCN), and intraductal mucinous papillary neoplasm (IPMN)—is likely the correct one requires the careful integration of many historical, radiographic, laboratory, and other factors, and management is markedly different depending on the type of cystic lesion of the pancreas. Pseudocysts are generally distinguishable based on historical, clinical and radiographic characteristics, and among the others, the most important differentiation is between the mucin-producing MCN and IPMN (high risk for cancer) versus the serous SCN and SPN (low risk for cancer). EUS with FNA and cyst-fluid analysis will continue to play an important role in diagnosis. Among mucinous lesions, those that require treatment (resection currently) are any MCN, any MD IPMN, and BD IPMN larger than 3 cm, symptomatic, or with an associated mass, with the understanding that SCN or pseudocysts may be removed inadvertently due to diagnostic inaccuracy, and that a certain proportion of SPN will indeed be malignant at the time of removal. The role of ethanol ablation is under investigation as an alternative to resection in selected patients

Adult Pancreatic Hemangioma: Case Report and Literature Review

We report an adult pancreatic hemangioma diagnosed on pathological specimen review following pylorus preserving pancreaticoduodenectomy for a symptomatic cystic mass in the head of the pancreas. Eight cases of adult pancreatic hemangioma have been reported in literature since 1939. Presenting symptoms, radiographic diagnosis, pathologic characteristics, and treatment of adult pancreatic hemagiomas are discussed following review of all published cases

Resected serous cystic neoplasms of the pancreas: Locally aggressive behavior as a predictor of malignant disease? A review of 158 patients with recommendations for treatment.

Background: Serous cystic neoplasms of the pancreas are regarded as a benign entity with rare malignant potential. Surgical resection is generally considered curative. Objective: To perform the largest single institution review of patients who underwent surgical resection for serous cystic neoplasms of the pancreas in the hopes of guiding future management. Methods: Between June 1988 and January 2005, 158 patients with serous cystic neoplasms of the pancreas underwent surgical resection. A retrospective analysis was performed. Univariate and multivariate models were used to determine factors influencing perioperative morbidity and mortality. Major complications were defined as pancreatic fistula or anastomotic leak, postoperative bleed, retained operative material, or death. Minor complications were defined as wound infection, postoperative obstruction/ileus requiring TPN, delayed gastric emptying, arrhythmia, or other infection. Results: The mean age of the patients was 62.1 years, with 75% being female. The majority of patients were symptomatic at presentation (63%), with abdominal pain as the most common symptom. Of the 158 patients, 75 underwent distal pancreatectomy, 65 underwent pancreaticoduodenectomy, 9 underwent central pancreatectomy, 5 underwent local resection or enucleation, and 4 underwent total pancreatectomy. Mean tumor diameter was 5.1 cm. Mean operative time was 277.5 minutes. Mean postoperative length of hospital stay was 11 days. One patient was diagnosed at presentation with serous cystadenocarcinoma. The remaining 157 patients were initially diagnosed with benign serous cystadenoma. One of three patients with locally aggressive benign disease later presented with metastatic disease. Resection margins for all 158 patients were negative for tumor, and only 1 (0.6%) showed lymph node involvement. There was one intraoperative death. The incidence of major perioperative complications was 18%, while the incidence of minor complications was 33%. Men were significantly more likely to experience minor perioperative complications (OR = 3.74, P = .008), while patients greater than 65 years showed a trend toward fewer major complications (OR = 0.36, P = .09). Conclusions: Serous cystic neoplasms of the pancreas which are surgically resected are typically seen in asymptomatic women, as 5 cm neoplasms which are predominantly benign. Most are resected via either a left or right sided pancreatectomy with low mortality risk, but with notable major or minor morbidity. Cystadenocarcinoma is a rare finding on initial resection of serous cystic neoplasms. However, initial pathology specimens exhibiting benign but locally aggressive neoplasia may indicate an increased likelihood of recurrence or metachronous metastasis