bluuebunny/crossref_metadata_2025_split huggingface dataset:
2532 Lynch Syndrome With Lung Adenocarcinoma and Their Response to Nivolumab
Authors: Tambe Ajay , Benjamin Sam , Badrinath Madhuri 
Published: October 2019

INTRODUCTION:
Lynch syndrome is caused by mutations in mismatch repair genes which cause microsatellite instability (MSI). Patients with Lynch syndrome are at high risk for developing synchronously and metasynchronously developing colorectal, uterine, ovarian, stomach, small bowel, pancreatic, kidney and brain cancers; however, the risk of lung cancer is same as that of general population. Programmed death-1 (PD-1) inhibitors such has nivolumab have shown good overall response rate in patients with mismatch repair-deficient non-colorectal cancers.

CASE DESCRIPTION/METHODS:
A 72-year-old female with 57-pack-year history of smoking was diagnosed with stage IV adenocarcinoma of the transverse colon in 2007. She underwent resection of the transverse colon followed by chemotherapy. In 2016, she was diagnosed with stage IV duodenal carcinoma with metastasis to the liver. A 14.4 mm right lower lobe nodule was also seen on computed tomography (CT) scan (Figure 1). This nodule was suspected to be metastatic from the duodenal carcinoma, however, biopsy of this nodule showed it to be poorly differentiated adenocarcinoma of the lung. Staining was positive for TTF-1 and CK7 confirming it to be a primary lung cancer. Since this was a stage 1 adenocarcinoma, testing for PD-L1 expression was not done. EGFR, ROS, ALK-1 and BRAF mutations were negative. The patient's mother had breast cancer, father had lung, stomach and liver cancer while her sister had lung cancer with metastases to the brain. Given this history, familial cancer syndrome was suspected and microsatellite instability was tested. Loss of MSH2 and MSH6 was detected via immunohistochemistry (IHC) in duodenal cancer, making it a high-frequency MSI (MSI-H) tumor. Immunotherapy with Nivolumab was started in April 2017 and CT scans 8 months later showed markedly decreased size of the duodenal mass and the hepatic metastases while the lung nodule was reduced to 9.7 mm (Figure 2).

DISCUSSION:
As per the results of CHECKMATE-142 trial, immunotherapy with Nivolumab has shown durable response and disease control in pre-treated patients with DNA mis-match repair deficient/MSI-H metastatic colorectal cancer. PD-L1 tends to be expressed at higher levels in MSI-H cancers than in microsatellite-stable cancers. Even though lung adenocarcinoma was not tested for PD-L1 expression, it was likely to be high given its response to Nivolumab. The findings of this case suggest that lung adenocarcinoma in patients with Lynch syndrome may be susceptible to immune check-point blockade.
2606 Primary Immunodeficiency Manifesting as Chronic Diarrhea
Authors: Kalantri Shreyas , Shrimanker Isha , Nair Sujit , Rathi Pravin 
Published: October 2019

INTRODUCTION:
Common variable immunodeficiency (CVID) is a primary immunodeficiency disease described by reduced concentrations of immunoglobulins, mainly IgG, IgA and/or IgM. CVID affects both humoral and cell-mediated immunity, resulting in a myriad of infections. Gastrointestinal infections form the second most prevalent infections.

CASE DESCRIPTION/METHODS:
A 24-year-old Asian male presented with chronic watery stools associated with borborygmi, fatigue, and weakness since 10–12 years. He complained of increased frequency of stools, 5–6 episodes during the day and around 1–2 episodes at night. The stools were large in volume, occasionally foul-smelling but without any mucus or blood. He denied any urgency, tenesmus, precipitancy or bloating. He had an unintentional weight loss of 15 kgs in the past five years but denies loss of appetite. On arrival, he had a pulse of 82 beats/minute blood pressure of 110/70 mm Hg. Physical exam was not significant for any abnormality. Laboratory investigations showed hemoglobin of 9.7 gm/dl, sodium of 140 mEq/l, potassium of 3.2 mEq/l, calcium of 7.6 mg/dl, phosphorous of 3.3 mg/dl, total protein of 4.6 g/dl with albumin of 3.1 g/dl, alkaline phosphatase of 241 U/L. Workup for viral markers was negative. Immunoglobulin levels were IgA < 6.67 mg/dl, IgM of 42 mg/dl and IgG of 788 mg/dl. Esophagogastroduodenoscopy revealed diffuse nodularity in D1 and D2 (Figure 1) regions along with mild antral gastritis. Biopsy of the duodenal nodule revealed acute on chronic duodenitis with marked lymphoid aggregates (Figure 2) and also antral biopsy was suggestive of moderate chronic antral gastritis with lymphoid aggregates with detection of Helicobacter pylori 1 +. Colonoscopy up till the terminal ileum did not reveal any abnormality. Computed tomography of the abdomen with enterography revealed redundant sigmoid colon resulting in displacement of small bowel loops in the right half of the abdomen along with mucosal thickening and irregularity in the distal pylorus. The patient was treated with multivitamins along with replenishment of fat-soluble vitamins. He had a resolution of symptoms and was followed up on an outpatient basis.

DISCUSSION:
Patients with CVID have greater susceptibility to develop gastrointestinal malignancies and infectious and inflammatory conditions. Physicians should thus remain vigilant regarding chronic diarrhea and think of broad differential diagnosis including primary immunodeficiencies.
2612 Gastrointestinal Stromal Tumor Causing Obscure Gastrointestinal Bleeding: An Uncommon Way of Diagnosing an Uncommon Disease
Authors: Dziadkowiec Karolina N. , Satiya Jinendra , Katz Aviv 
Published: October 2019

INTRODUCTION:
Gastrointestinal stromal tumors (GISTs) are neoplasms which arise from the tissue of the gastrointestinal tract or, rarely, from other intra-abdominal tissues. CT angiography can be utilized as an alternative imaging study when endoscopic and colonoscopy results are non-diagnostic. We report a case of a 59 year-old-female who presented with recurrent episodes of obscure overt gastrointestinal bleeding and was found to have a GIST.

CASE DESCRIPTION/METHODS:
A 59-year old woman with history of gastro-esophageal reflux disease presented to the emergency room with bright red blood per rectum and lower abdominal pain for one month. She reported one episode of melenic stool. Physical examination was unremarkable. Laboratory findings revealed a hemoglobin of 9.4 g/dL and a positive fecal occult blood test. Esophagogastroduodenoscopy (EGD) was non-diagnostic. Colonoscopy revealed fresh blood with clots at the terminal ileum, but no evident source of bleeding was identified. As the source of bleeding could not be accurately diagnosed with routine colonoscopy and EGD, an abdominal computed tomography angiography (CTA) was obtained. Abdominal CTA revealed a large exophytic, necrotic mass with hypervascularity to the right of the uterine fundus along with extensive vessels within the bowel wall. The mass, distal portion of the distal jejunum, portion of the terminal ileum were resected. Postoperative pathological examination revealed gastrointestinal stromal tumor (high grade, spindle cell variant). The patient is doing well at a four-month follow-up.

DISCUSSION:
Patients with GISTs can often be asymptomatic leading to a missed initial diagnosis. When symptomatic, patients often present with bleeding, anemia, mucosal ulceration or mass effect, depending on location. Occasionally they are discovered as incidental findings in radiologic imaging or as incidental findings during surgery or autopsy. Bleeding is the most common presenting symptom and is attributed to the erosion of the gastrointestinal tract lumen with tumor invasion, resulting in hematemesis, melena or anemia. This case offers a unique perspective of GIST diagnosis. In cases where a colonoscopy and EGD along with abdominal series is undiagnostic and capsule endoscopy/balloon enteroscopy are not available - CT angiography can be considered an alternative imaging procedure for the management of GIST tumors. In our case, CT angiography provided exact tumor location preoperatively allowing for appropriate surgical resection.
2638 Intestinal Pseudo-Obstruction Associated With Seropositive Myasthenia Gravis, Thymoma, and Positive CV-2 Antibodies
Authors: Gonzalez Adalberto , Castillo Michael , Rajagopalan Rajaganesh , Castaneda Daniel , Castro Fernando 
Published: October 2019

INTRODUCTION:
Intestinal pseudo-obstruction (IPO) is a rare condition characterized by signs and symptoms of bowel obstruction without an identifiable mechanical cause. Antibody-mediated paraneoplastic syndromes and autoimmune diseases have been reported as two potential etiologies. We report a unique case of IPO presenting with thymoma, myasthenia gravis (MG), and positive CV-2 antibodies.

CASE DESCRIPTION/METHODS:
A 43 year old previously healthy female presented to the ED with abdominal pain, nausea and vomiting. This was her third visit to the ED in the past week for similar symptoms. On admission, laboratory studies were normal. A CT of the abdomen revealed marked gastric and small bowel distention, fecal impaction, and a mediastinal soft tissue density (Figure 1). She was initially managed medically with restriction of oral intake, intravenous fluids, and a nasogastric tube. Since she did not improve after several days, she was taken to the operating room for a diagnostic laparoscopy, which did not show evidence of mechanical obstruction. A CT chest with contrast done to investigate the mediastinal soft tissue density revealed an anterior mediastinal mass.A chest MRI had changes suggestive of a thymoma. This was subsequently confirmed by biopsy. Given the suspicion for a paraneoplastic process, multiple serologic markers were ordered. Acetylcholine receptor (AChR) antibodies and CV-2 antibodies were positive (Table 1). She was diagnosed with paraneoplastic intestinal pseudo-obstruction. The patient was treated with IV methylprednisolone and pyridostigmine with marked improvement in symptoms.

DISCUSSION:
The association of IPO as a paraneoplastic syndrome of thymoma and myasthenia gravis has been reported in only a few cases. The pathophysiology involves AChR antibodies targeting the neuronal nicotinic acetylcholine receptors present on autonomic ganglia. Our patient had positive AChR antibodies. She had no other symptoms of MG, indicating isolated autonomic dysfunction. IPO has also been associated with malignancies such as small cell lung cancer, which may be mediated by a variety of autoantibodies. Anti-Hu antibody has been most commonly implicated but was negative in this case. Anti-CV2 antibody was positive, which was reported in only one previously published case. In summary, patients with thymomas or MG should have testing for paraneoplastic antibodies; they tend to respond to treatment with immunosuppression and acetylcholinesterase inhibitors.
2647 A Case of Potentially Three Recurrences of Gallstone Ileus
Authors: Loudin Michael , Koprowski Steven T. 
Published: October 2019

INTRODUCTION:
Gallstone ileus is rare in the general population; however, the proportion is much higher in older populations and one third of the affected patients suffer from serious medical comorbidities. Literature on intervention strategies are limited to retrospective reports with optimal intervention remaining unclear. Recurrence of gallstone ileus reaches 5%, which provides a unique dilemma for treatment approaches in patients already at higher peri-operative risk.

CASE DESCRIPTION/METHODS:
A 68-year-old male with prior history of hypertension and GERD presented with abdominal pain, nausea, bilious emesis, reduced flatus over 4 days. He had experienced a similar episode a few weeks prior that spontaneously resolved. Exam showed sinus tachycardia, but other vitals were normal. The abdomen was distended, tympanic, and moderately tender in the epigastrium without evidence of peritonitis. Labs were pertinent for a mild acute kidney injury, but were otherwise within normal limits. A CT abdomen/pelvis showed findings of small bowel obstruction with pneumobilia (Figure 1a). He ultimately underwent enterolithotomy yielding a 4 cm gallstone at the site of intestinal obstruction. Six months later, he returned with a similar presentation and was found with recurrence of gallstone ileus, this time with a 3 cm gallstone in the same location. He then underwent bowel resection with side-to-side jejunal anastomosis. Within two weeks of his second procedure, his symptoms returned and repeat CT showed recurrence of gallstone ileus at the former anastomosis site with a 2.0 cm partially obstructing gallstone. Given the recent surgical intervention, conservative measures were trialed and he was discharged on a full liquid diet. He was admitted two months later for cholecysectomy and resection of prior jejuno-jejunal anastomosis. The post-operative course was complicated by subhepatic fluid collection that was drained. At his 1-year follow-up, he was symptom free.

DISCUSSION:
Recurrence of gallstone ileus is not common and it is important for the medical team to consider underlying comorbidities of this population before proceeding with a complicated/multi-step surgical procedure. After review of the literature, enterolithotomy alone is the most recommended strategy for initial intervention. If a patient has minimal pre-existing co-morbidities, a staged, elective cholecystectomy and resection of chole-enteric fistula can be effective in preventing/treating recurrence.
2651 Secrets of the Ampulla: A Rare Neuroendocrine Tumor
Authors: Bofill Aliana , Mirza Zeyn , Estremera Rodolfo , Martin Jose 
Published: October 2019

INTRODUCTION:
Neuroendocrine tumors (NETs) of the ampulla of Vater represent less than 0.3% of gastrointestinal NETs and less than 2% of all periampullary malignancies. There are approximately 139 cases in literature, making this rare condition a diagnostic challenge. Jaundice is the predominant symptom followed by abdominal pain. Acute pancreatitis as the initial presentation has seldom been reported. Herein we report a case of a patient who presented with acute pancreatitis and biliary obstruction secondary to an ampullary NET.

CASE DESCRIPTION/METHODS:
Case of a 74-year-old male with hypertension who reported burning epigastric pain. Denied fever, vomits, weight loss, diarrhea, flushing or dyspnea. Physical examination with epigastric tenderness. Laboratories showed elevated alkaline phosphatase 398 U/L, total bilirubin 3.4 mg/L, lipase 594 U/L and amylase 216 U/L. Contrast abdominopelvic CT showed a duodenal periampullary mass with common bile duct measuring 1.1 cm and intrahepatic and extrahepatic dilatation. Endoscopic retrograde cholangiopancreatography (ERCP) revealed an irregular, ulcerated ampullary mass. Biopsy showed poorly differentiated carcinoma. Immunostains were positive for chromogranin, synaptophysin, CK7, weakly positive for CDX-2. Negative for TTF-1 and CK20. Octreotide scintigraphy with no uptake. Somatostatin, chromogranin, and 5-hydroxy-in-dole acetic acid were normal. Patient underwent surgical treatment with pancreaticoduodenectomy.

DISCUSSION:
The rarity of ampullary NETs and its proliferation under an intact mucosa makes it difficult to detect in biopsy. Most of the time the diagnosis is based on histology and preoperative diagnosis may be challenging since they clinically present like adenocarcinoma. The usual presentation of jaundice and abdominal pain places this diagnosis low on the differential. In our case, the unusual morphologic appearance likely facilitated obtaining an assertive pre-operative diagnosis. Our patient presented with obstructive jaundice and acute pancreatitis, which occurs in less than 6% of cases. The clinical picture of ampullary NETs is easily confounded given the associated symptoms and biopsy challenges. A high index of suspicion is paramount to ensure this rare diagnosed is not missed. Pancreaticoduodenectomy has been advocated as the treatment of choice regardless of size due to high risk of occult nodal metastases. Considering this diagnosis within the differential is important given the drastically different outcomes for patients if caught early.
2675 A Rare Case of Bleeding Isolated Gastric Varices in the Setting of Non-Cirrhotic Portal Hypertension
Authors: Gonzalez Hector H. , Ohanisian Levonti , Bank Michael , Sidhu Simran 
Published: October 2019

INTRODUCTION:
Non-cirrhotic portal hypertension (NCPH) is a rare manifestation of non-cirrhotic etiology, with gastric varices reported to occur in less than 10% of cases. Current literature hopes to identify cases in order to specify future diagnosis modalities and treatment. We present the second patient in the english literature to present with NCPH causing isolated Gastric Varices (IGV) in the absence of an identifiable etiology.

CASE DESCRIPTION/METHODS:
A 53 year old male with past medical history of diverticulitis presented to the emergency department with hematemesis and melena. He denied alcohol abuse or NSAID use. Physical exam showed BP 81/49 mmHg and non-radiating epigastric tenderness. Labs showed Hb10.4, platelet count 144,000, and BUN 39. Lipase, liver function and coagulation panel were normal. Ethanol, tylenol, and drug screen were negative. Viral hepatitis panel was negative. Patient was started on IV fluids, PPI, octreotide, and transfused two units PRBC. Emergent esophagogastroduodenoscopy (EGD) showed no bleeding source with adherent clot in fundus of stomach. Computed tomography (CT) of the abdomen with contrast showed a patent portal vein. Repeat EGD later showed moderate-sized IGV type I in fundus and GE junction ulceration. The varices were banded and ulceration clipped. Patient was treated with IV ceftriaxone, octreotide, and PPI. MRI of the abdomen showed 1.9 cm nodule in posterior hepatic dome, with portal hypertension. A nuclear scan of liver and spleen showed no colloid shift. Ultrasound of hepatic vessels showed no evidence of portal vein thrombosis with hepatopetal flow. Patient responded well to therapy, was initiated on beta blockers, and given appropriate outpatient follow up.

DISCUSSION:
Isolated Gastric Varices (IGV) are typically associated with thrombosed splenic vein, and occur most commonly in patients with portal hypertension. There are two main subtype: IGV1 located in the fundus, and IGV2 located in pylorus, body, and cardia. It is important to consider all possible etiologies attributable to portal hypertension when evaluating gastric varices on EGD. Despite the fact that they occur more frequently than esophageal varices, IGV carry a higher likelihood of mortality. Current treatment modalities include: airway protection, hemodynamic stabilization, somatostatin analogues, prophylactic antibiotics, and early endoscopic intervention. Additional studies are needed to further advance the knowledge of IGV, and establish a consensus on appropriate treatment modalities.
2688 Blame It on the Migrating Stent: A Case Report
Authors: Phan Ethan , Patel Pratik , Gollol Raju Narasimha Swamy , Mudireddy Prashant 
Published: October 2019

INTRODUCTION:
Endoscopic implantation of plastic or metal stents is widely used to manage gastric and biliary disorders. However, complications from stent migration have also been well-documented. Biliary stents usually pass through the intestine without complications. In the case where invasive intervention is necessary, endoscopic retrieval is preferred to prevent surgical intervention. We report an acute abdominal pain case presumably from stent migration.

CASE DESCRIPTION/METHODS:
A 56 yo woman with past medical history of SMA chronic mesenteric ischemia status post revascularization and choledocholithiasis status post stent placement presented to the hospital for acute abdominal pain with nausea and vomiting. One month ago, she had a metal common bile duct stent placed for choledocholithiasis with biliary obstruction. Imaging showed showed the dislodged stent and mild mid-small bowel loop thickening with mid-small bowel stent. Initially, gastroenterology recommended watchful waiting and she was discharged home in stable condition. She returned to the hospital for persistent abdominal pain. Repeat imaging showed the dislodged common bile duct stent within the distal loop of small bowel, now appearing abnormally thickened and hyperemic but no evidence for bowel obstruction. After review with the surgery team, she was taken for combined mesenteric angiogram and exploratory laparotomy as the stent was inaccessible by endoscopy due to its location. On angiogram, all GI vasculature was patent, however a stricture was found adjacent to the stent. The strictured bowel was surgically resected and the stent was removed. The stricture was related to the ischemic changes that she previously suffered from prior revascularization. Abdominal pain improved and she was discharged home after tolerating a regular diet.

DISCUSSION:
This case illustrates that when abdominal pain is out of proportion to the physical exam, a broader differential would provide a different perspective. Initially, the diagnosis was homed in on the stent migration as the etiology of acute abdominal pain. Unfortunately, histories of previous abdominal surgeries and SMA revascularization were not explored until later. The stricture was only discovered after exploratory laparotomy. This case demonstrates premature diagnosis can be detrimental to patient care. It is imperative to understand the entirety of the patient’s history in order to make not only the correct diagnosis but to intervene in a timely manner to prevent morbidity and mortality.
2704 Urosepsis Is Difficult to Stomach!
Authors: Jarodiya Vijay , Kher Chirag , Singh Tejveer , Khan Zarak 
Published: October 2019

INTRODUCTION:
Gastric ischemia is a rare condition associated with poor prognosis typically presenting with abdominal pain, GI bleed and altered mentation and may be caused due to states of shock. We present a rare case of gastric ischemia due to urosepsis.

CASE DESCRIPTION/METHODS:
A 70 year-old male with past medical history of peripheral vascular disease, chronic Foley catheter and dementia presented with altered mentation, hypotension, tachycardia and decreased urine output. The Foley catheter was replaced revealing purulent urine. Initial labs revealed acute kidney injury, lactic acidosis, and leukocytosis. CT abdomen pelvis without contrast revealed gastric pneumatosis with adjacent left upper quadrant portal venous gas and branching portal venous gas throughout the liver. Esophagogastroduodenoscopy was performed which showed proximal gastric ischemia and necrosis from the midbody to the fundus; biopsies revealed acute hemorrhagic gastritis, and gastroenterology recommended resection. General surgery was consulted who recommended conservative management. Patient improved clinically while receiving antibiotic therapy, intermittent nasogastric tube suction, intravenous proton pump inhibitor therapy and parenteral nutrition. Repeat imaging showed resolution of portal gas and gastric pneumatosis and repeat EGD showed resolution of gastric ischemia.

DISCUSSION:
Gastric ischemia is a serious condition which is under-recognized clinically. Etiologies include systemic hypotension, vasculitis or disseminated thromboembolism. Gastric pneumatosis or portal venous gas on imaging suggest ischemia; EGD with biopsy is the diagnostic gold standard. Gastric ischemia is either managed surgically or medically with fluid resuscitation, nasogastric tube placement to prevent gastric distension and acid reduction along with antibiotics for patients with gastric pneumatosis.