bluuebunny/crossref_metadata_2025_split huggingface dataset:
1543 Melanoma Coli: A Rare Case of Diffuse Metastatic Melanoma to the Colon Presenting as Diarrhea
Authors: Zhang Daniel S. , Shen Steven , Mathur Neha 
Published: October 2019

INTRODUCTION:
An 84-year-old male with history of melanoma of his left ear removed six years ago with clear margins presented to the hospital with a one year history of worsening diarrhea and weight loss, but denied rectal bleeding. Labs showed anemia of chronic disease, elevated inflammatory markers, with infectious and chronic diarrhea workup negative. Upper endoscopy was unremarkable, however colonoscopy showed a large 3 cm fungating, ulcerated, infiltrative mass within the cecum with multiple masses throughout the colon (Figure 1a,b). Biopsies were taken from the multiple masses, which all showed colonic mucosa with infiltrating epithelioid and plasmacytoid cells with frequent mitotic figures (Figure 2c,d). Immunohistochemical staining was positive for melanocytic markers S100, HMB45 and Sox10 consistent with malignant melanoma (Figure 3e–g). Further molecular testing showed positive BRAF and NRAS mutations, which are reported in 13-25% of malignant melanomas.

CASE DESCRIPTION/METHODS:
Metastatic melanoma to the colon is rare due to the absence of melanocytes in the colon apart from the ano-rectal region. More than 95% are diagnosed post-mortem, which is. The average interval between diagnosis of primary melanoma and discovery of colonic involvement is between 5-7 years. The overall incidence of large bowel metastasis is 0.3% with a mean age at diagnosis of 57.8. Hematochezia is the most common symptom, followed by anemia, obstruction and perforation. Primary therapy is based on chemotherapy and immunotherapy, unless surgical intervention is required for obstructive symptoms or perforation. Overall prognosis remains poor with an average survival of 7 months and a 5-year overall survival of 25%.

DISCUSSION:
Here we present a rare case of metastatic melanoma to the colon as a cause of diarrhea and anemia. This should always be considered in any patient with a remote history of melanoma.
1546 Idiopathic Myointimal Hyperplasia of Mesenteric Veins: A Rare Cause of Treatment Refractory Colitis
Authors: Oruganti Poornima , Awan Rehmat Ullah , Sugimoto Matthew , Tey Kai Rou , Nunez-Herrero Laura , Ding Xianzhong , Ma Yihong , Abegunde Ayokunle T. 
Published: October 2019

INTRODUCTION:
Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare disease which mimics inflammatory bowel disease (IBD) clinically and endoscopically while showing ischemic changes without classic features of IBD on pathology. Delay in diagnosis is common; definitive diagnosis is usually only feasible after surgical resection.

CASE DESCRIPTION/METHODS:
A 62-year-old male with a past medical history of hypertension and hyperlipidemia presented with a 1-year history of recurrent abdominal pain, bloody diarrhea, and rectal pain. He was initially evaluated at another hospital and diagnosed with pneumatosis intestinalis and left-sided colitis. Left colon biopsies were suggestive of ischemia but computerized tomography angiogram (CTA) revealed patent mesenteric arteries. Extensive workup for thrombophilia, infectious, inflammatory, and autoimmune etiologies were negative. His symptoms did not respond to antibiotics and oral steroids. He presented to our institution for a second opinion. At presentation, he was diaphoretic, afebrile and in distress. Physical exam was significant for lower abdominal tenderness without peritoneal signs. Laboratory investigations revealed elevated inflammatory markers (Table 1). Repeat CTA showed patent mesenteric arteries. Colonoscopy revealed severe inflammation and congestion extending from the mid-transverse colon to the rectum. The terminal ileum and ascending colon were normal. Biopsies from inflamed mucosa revealed ischemic colitis with fibrinoid microvascular wall necrosis and fibrin thrombi (Figure 1). He was started on IV Methylprednisolone 40 mg daily but symptoms progressed despite IV steroids. He underwent total colectomy with end ileostomy which was curative. Histopathological analysis of the resected colon confirmed IMHMV.

DISCUSSION:
Current opinion suggests that IMHMV is caused by non-inflammatory, non-thrombotic obliteration of medium-to-large size mesenteric veins. IMHMV is a difficult diagnosis to make preoperatively. However, preoperative diagnosis is suggested by the presence of arterialized capillaries, subendothelial fibrin deposits and fibrin thrombi on endoscopic biopsies. IMHMV is typically refractory to steroids and biologics. Gastroenterologists and pathologists should have a high index of suspicion for IMHMV in patients with treatment refractory colitis, negative mesenteric angiography and colon biopsies showing ischemic changes without classic features of IBD. Colectomy is usually curative without recurrence of symptoms.
1547 Pseudomonas Aeruginosa: A Rare Cause of Community-Acquired Antibiotic-Associated Diarrhea in an Immunocompetent Adult
Authors: Hoff Ryan T. , Patel Ami , Shapiro Alan 
Published: October 2019

INTRODUCTION:
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic gram negative pathogen known to cause enterocolitis in children and nosocomial infections, including hospital acquired pneumonia (HAP) and catheter associated urinary tract infections (UTIs). Rarely, P. aeruginosa causes antibiotic-associated diarrhea in immunocompromised hosts, but this has not been reported in immunocompetent ambulatory hosts.

CASE DESCRIPTION/METHODS:
An 81 year old previously healthy woman presented to the emergency department (ED) with diarrhea for 2 days. A week prior to symptom onset, she completed a 17 day course of ciprofloxacin for a UTI, with resolution of dysuria. She described frequent, watery, nonbloody bowel movements with nausea and emesis. She was treated with intravenous saline and ondansetron, and discharged. The next day, she developed bloody bowel movements associated with weakness and mild lower abdominal pain. With ongoing diarrhea, she returned to the ED. Physical exam showed very mild left lower quadrant abdominal tenderness, without rebound or guarding. Laboratory studies showed white blood cell count 11,800 cells/mcL, potassium 3.3 meq/dL, and lipase 67 units/L. Electrolytes and liver enzymes were otherwise normal. Clostridium difficile (C difficile) stool toxin PCR was negative. CT abdomen and pelvis without contrast showed diverticulosis and mild inflammation surrounding the sigmoid colon (Figures 1 and 2). She was started empirically on ciprofloxacin and metronidazole, and admitted to the medical floor. Over the next 3 days, she gradually improved. Stool culture grew P. aeruginosa, with absence of normal fecal flora. Sensitivities showed resistance to ciprofloxacin and levofloxacin. Given her clinical improvement, antibiotics were discontinued after 7 days.

DISCUSSION:
We report a case of P. aeruginosa as a cause of bacterial colitis. Our patient's prior antibiotic therapy may have increased her susceptibility to this infection via loss of normal fecal microbiota, leading to a loss of competitive exclusion and diminished colonic barrier protection. To our knowledge, this is the first reported case of post-antibiotic diarrhea caused by P. aeruginosa in an immunocompetent ambulatory host. This may be an important diagnostic consideration in patients presenting with persistent diarrhea following antibiotics, with negative C. difficile stool testing. The role for antibiotic therapy in Pseudomonas associated diarrhea warrants further research.
1549 Intermittent Hematochezia Due to Colonic Endometriosis
Authors: Tielleman Thomas J. , Wachsmann Megan B. , Hammer Suntrea , Ahmed Tasneem F. 
Published: October 2019

INTRODUCTION:
Endometriosis is a disease defined by the presence of endometrial epithelium implanted outside of the uterus. The prevalence in reproductive age women is 10-15%, with the most common site being the ovaries. However, gastrointestinal involvement of endometriosis has been reported to occur in 3-37% of patients with endometriosis, with the rectosigmoid colon being the most common gastrointestinal site of involvement. The disease is usually diagnosed by imaging and surgical techniques whereas colonoscopy is not typically considered a mode of diagnosis for colonic endometriosis.

CASE DESCRIPTION/METHODS:
A 46 year old female with past medical history significant for OSA on CPAP, Secondary Polycythemia, HTN, HLD, Depression, and history of hysterectomy with tubal ligation 20 years prior presented as a referral for colonoscopy in the setting of intermittent rectal bleeding. She reported a ten month history of monthly episodic pelvic pain and mild rectal bleeding not associated with bowel movements. The timing of the bleeding was similar to her normal menstrual cycle. However, she denied vaginal bleeding and reports that she had a total abdominal hysterectomy 20 years prior due to a “cyst” on her uterus. In the 2 months prior to colonoscopy, the patient also developed some blood coating her stools intermittently during bowel movements as well. On presentation, patient's vital signs were within normal limits. Cardiac and pulmonary examination were normal. Abdomen was soft, non-tender, and non-distended with normal bowel sounds. On colonoscopy, the patient was found to have small non-bleeding external hemorrhoids, a 5 mm tubular adenoma in the transverse colon, and a 13 mm lesion in the recto-sigmoid colon that appeared to be arising from a depression in the mucosa. Initial attempt to lift lesion with 5 cc of Eleview injected into the submucosa was unsuccessful. Ultimately, the lesion was removed with hot snare. Pathology revealed endometriosis involving the mucosa and submucosa.

DISCUSSION:
Endometriosis is an uncommon cause of rectal bleeding. In young female patients of reproductive age, this should be on the differential. Moreover, it is important to keep this in mind in post-menopausal women as well.
1550 Overflow Diarrhea in the Setting of Urinary Retention
Authors: Van Jeremy , Abraham Rana 
Published: October 2019

INTRODUCTION:
Overflow or paradoxical diarrhea is the seepage of stool around an intestinal impaction. This is typically described in patients whom have chronic constipation. There have been cases described of bowel compression from malignancy or even urinary retention causing bowel obstruction. To our knowledge, there are no reports of overflow diarrhea in patients with urinary retention which resolved after starting clean intermittent catheterization (CIC) for urinary drainage.

CASE DESCRIPTION/METHODS:
A 43 year old male with past medical history of peptic ulcer disease s/p gastrectomy with Billroth II anastomosis, GERD, Barrett's Esophagus, and Schizoaffective disorder presented with a 2 month history of 15+ loose, watery stools and abdominal pain daily along with a 2 year history of urinary retention. To work up the patient's diarrhea, celiac serologies, c-reactive protein (CRP), stool culture, stool ova and parasite, fecal pancreatic elastase, and CT abdomen/pelvis w/o IV contrast were ordered. CRP and celiac disease serologies were unremarkable and he never completed his outpatient stool studies. CT displayed a severely distended bladder compressing the small and large bowel without distension of bowel loops. He subsequently visited a Urologist and was diagnosed with myogenic bladder failure. After starting CIC, the patient was down from 15+ loose stools to 2-3 semi-solid stools daily and his abdominal pain resolved.

DISCUSSION:
Commonly, there can be extrinsic compression of the bowel from entities such as malignancy and adhesions. Overflow diarrhea is typically seen in patients with constipation. In this patient, he likely experienced multiple loose stools daily from stool seepage past bowel compression created by a distended bladder. No antibiotics were taken prior to his diarrhea occurring and he had no changes in diet. Fecal elastase testing, stool culture, and stool ova and parasites weren't completed, but pancreatic insufficiency and infection were less likely given his improvement with CIC. In patient's whom are having both urinary retention and diarrhea, it is important to rule out overflow as an etiology for diarrhea. This case also highlights the bidirectional relationship between urinary retention and constipation.
1553 A Phantom of the Large Bowel!
Authors: Amarnath Shivantha , Fady Haddad , Deeb Liliane 
Published: October 2019

INTRODUCTION:
Giant colonic diverticulum (GCD), referred to as giant colon cyst or “phantom tumor,” is a diverticulum that commonly arises from sigmoid colon and is larger than 4 cm in diameter. This occurs mostly in individuals older than 60 years and its pathogenesis is not well understood. Two theories have been proposed that could co-exist: A one-way valve mechanism at the transition point between the bowel lumen and diverticulum permitting air entry and progressive increase in intraluminal pressure with subsequent enlargement of the diverticulum. Alternatively, gas forming bacteria encased within a cyst of the colon contributing to chronic inflammation and consequent gradual distention of a diverticulum. Patients are mostly asymptomatic, otherwise common clinical manifestations range from a soft palpable abdominal mass to lower abdominal pain, constipation or rectal bleeding. However, it is uncommon for GCD to present as acute diverticulitis, and to our knowledge, this is a rare case to be reported in the literature. Herein we report a case of an elderly male who presented with sepsis due to acute diverticulitis as an initial presentation of a GCD.

CASE DESCRIPTION/METHODS:
A 63-year-old bed-bound male with a history of multiple sclerosis and major depression presented to our hospital with generalized abdominal pain of one-day duration. The patient was febrile at 101 F, and physical exam was remarkable for lower abdominal tenderness without guarding. He was septic with evidence of leukocytosis of 23,400/mm3, neutrophilia and lactate of 3 mmol/L (normal range: 0.5–2.2 mmol/L). A CT of the abdomen with contrast demonstrated an isolated 4.5 cm diverticulum at the sigmoid colon with evidence of acute diverticulitis. There was no evidence of a focal drainable abscess, free air or diverticulosis in other colon segments. He was considered high risk for surgery due to his sedentary status and was conservatively managed with parenteral antibiotics. His symptoms resolved and discharged three days later, without any further complications.

DISCUSSION:
GCD is a rare manifestation of diverticular disease and can present with a myriad of symptoms. Acute diverticulitis should be considered in those with evidence of sepsis and at risk of developing GCD. The gold standard treatment of en-bloc resection of the GCD with primary anastomosis is not always ideal for the management of this entity and a more conservative approach can be taken in high-risk surgical candidates as in our patient and may lead to a favorable outcome.
1558 Diffuse Primary Gastrointestinal Mantle Cell Lymphoma: A Rare Cause of Hematochezia
Authors: Singh Tamneet , Aggarwal Pankaj , Moreau Chris , Dominguez Cristian , Hughston Adam , Sayana Hari 
Published: October 2019

INTRODUCTION:
Mantle cell lymphoma (MCL) is non-Hodgkin lymphoma that classically does not involve the gastrointestinal (GI) tract. Although in some cases MCL has been shown to spread to the GI tract, primary gastrointestinal MCL is exceedingly rare and has only been described anecdotally. Often, the diagnosis of MCL is made once the disease is metastatic given its largely nonspecific symptom profile. We present a case of diffuse MCL of the GI tract presenting as hematochezia, in a patient with ulcerative colitis.

CASE DESCRIPTION/METHODS:
An 80-year-old male with history of newly diagnosed ulcerative colitis (UC) presented with four weeks of worsening diarrhea and hematochezia associated with a 30-pound weight loss over five months. He had been on mesalamine for UC, but had not experienced symptomatic relief. On admission, the patient was anemic to a hemoglobin of 9.3 g/dL, white blood cell count of 21.6 × 103/L with 13% bands and 48% atypical lymphocytes, and an albumin of 1.7 g/dL with normal platelets and INR. Abdominal imaging showed diffuse mesenteric lymphadenopathy concerning for a lymphoproliferative process and circumferential gastric, rectal and sigmoid wall thickening and edema. Clostridium Difficile (C. Diff) stool PCR was positive, and he was started on oral vancomycin therapy. Colonoscopy showed diffuse inflammation and edema of the colon with poor mucosal integrity and a hypertrophic mass in the ascending colon. Upper endoscopy showed diffuse, hypertrophied, thickened folds within the stomach and duodenum along with ulcerations. Endoscopic ultrasound was performed to biopsy para-aortic and celiac lymph nodes. Given high suspicion for lymphoma, a bone marrow biopsy was also obtained. Histopathology from the multiple biopsies were all consistent with Stage 4 pleomorphic Mantle Cell Lymphoma.

DISCUSSION:
This case describes a rare presentation of MCL, complicated by C. Diff colitis in addition to UC. There has been little data to show that these unique clinical entities are significantly correlated. Although hematochezia is a rare presentation of MCL, clinicians should maintain a high index of suspicion for malignancy and pursue additional imaging and/or procedures, even in a patient that has other reasons to present with hematochezia. This case of advanced stage MCL of the GI tract adds to a small body of literature regarding primary gastrointestinal MCL and warrants further research in to this rare gastrointestinal malignancy.
1562 Rare Intestinal Spirochetosis Masquerading as a Colonic Polyp
Authors: Pacha Faris , Skrove Jamie L. , Salhab Joseph , Pina Victor M. 
Published: October 2019

INTRODUCTION:
Spirochetosis in colonic mucosa is exceedingly rare in non-immunocompromised individuals. There have been less than 200 cases documented and more rare with the specific B. Pilosicoli genus. Spirochetosis is also seen in individuals who engage in high risk sexual encounters. This type of spirochetosis is found mosty in dogs, cats, pigs and chickens. Symptoms in humans include diarrhea, rectal bleeding, and abdominal cramps. Colonic spirochetosis is more common in third world countries. Even in immunocompromised state of health and with all other factors there is much unknown about colonic spirochetosis. Due to its infrequency the treatment is metronidazole and repeat colonoscopy and biopsy should symptoms persist.

CASE DESCRIPTION/METHODS:
Patient is a 62 year old male patient who presented as an outpatient consultation for screening colonoscopy. The patient complains of abdominal pain for several months that is localized in the right upper quadrant. The patient describes the pain as moderate to sharp and only last a few minutes after onset. Patient also reported post prandial fullness, abdominal bloating and distention. The patient denied rectal bleeding, melena, constipation, or pain on evacuation. The patient denies other symptoms. The patient has no medical history and only surgery was an elective laparoscopic cholecystectomy. The Decision was made to undergo screening colonoscopy. The patient had no history of immunocompromised state or HIV/AIDS. The patient denies anal sex. Colonoscopy revealed he had two polyps. One in the ascending colon and the other in the rectum. The specimens were sent for pathology for analysis. Ascending polyp was analyzed and it demonstrated colonic mucosa consistent with intestinal spirochetosis specifically Brachyspira pilosicoli. The rectal polyp was hyperplastic no adenomatous change.

DISCUSSION:
This case was chosen because only 200 known cases of colonic mucosa infected with spirochetosis have been documented. The patient is not immunocompromised, does not engage in anal sex, is not in a third world country, and does not have typical symptomatology of infection with Spirochetosis. In general colonic involvement with spirochetosis is very misunderstood due to its infrequency. The genus of B.pilosicoli. Is a spirochete genus that has limited data on how many cases have been documented. The presentation as a colonic polyp as a masquerade for actice spirochetosis infection prompts further study.
1566 Pylephlebitis and Intestinal Necrosis: An Unexpected Outcome of a Common Infection
Authors: Ilyas Suleman , Gonzalez Manuel O. 
Published: October 2019

INTRODUCTION:
Although rare, pylephlebitis should be included on the differential for any patient with CT imaging showing thrombosis in the portal vasculature, with a recent intraabdominal infection. Although there are not yet guidelines for management of this potential deadly complication, patients who received early antibiotics and anticoagulation have been associated with better outcomes.

CASE DESCRIPTION/METHODS:
A 59-year-old female presented with worsening abdominal pain two days after being discharged for uncomplicated diverticulitis, for which she was receiving a course of ciprofloxacin and metronidazole. Initial CBC was significant for a leukocytosis of 19.5 K/uL, and CT imaging revealed an inferior mesenteric vein (IMV) thrombosis extending up to her portal vein. She was continued on her antibiotics and started on unfractionated heparin for systemic anticoagulation. Despite these interventions, the patient continued to experience worsening abdominal pain, with physical exam revealing significant rebound tenderness. Interventional radiology (IR) guided aspiration on hospital day (HD) 6 as well as endoscopic aspiration on HD 9 were attempted. However, the location of the infectious process was prohibitively difficult to access. Repeat CT imaging done on HD 10 showed progressive septic thrombophlebitis with evidence of bowel ischemia. She underwent emergent washout with left colectomy and end colostomy. Throughout her admission, her course had been complicated by perforated diverticulitis and candida dubliniensis fungemia. The patient eventually improved and was discharged on HD 29. She was discharged to complete piperacillin-tazobactam (4 weeks of therapy), anidulafungin (6 weeks of therapy) and Coumadin (6 months of therapy).

DISCUSSION:
Pylephlebitis is a grave condition that can arise from common infections adjacent to the portal venous system. Diagnosis is now commonly made by imaging showing thrombosis in the portal vasculature. The mortality rate is significant, estimated to be 11-25%. Repeat imaging should be considered if there is lack of clinical improvement. Broad spectrum antibiotic therapy is a mainstay of treatment. Lower mortality rates and improved outcomes have been shown in those who were anticoagulated. Complications can be seen in up to 20% of patients, the most common of which are chronic thrombosis or extension of the thrombus, bowel ischemia and abscess formation. Surgery is not required for the initial management but can be used to obtain source control and manage complications.