bluuebunny/crossref_metadata_2025_split huggingface dataset:
1564 Hyper Progressive Disease (HPD) in a Colon Cancer Patient on Pembrolizumab
Authors: Lakkasani Saraswathi , Kollimuttathuillam Sudarsan , Dacosta Theodore , Guron Gunwant , Shaaban Hamid S. , Patel Kinjal 
Published: October 2019

INTRODUCTION:
Anti-programmed death one (PD1) and anti-programmed death ligand one (PDL1) has changed the prospective in the management of patients with advanced cancer. Where studies have shown significant response in some cases, a subset of patients might instead suffer from tumor flare. HPD is a term used to refer a drastic flare up of tumor with worsening clinical status in patients treated with PDL1 and PD1.

CASE DESCRIPTION/METHODS:
A 48-year African American female came with complaints of fatigue, abdominal pain and weight loss for four months. The CT scan of abdomen showed an extensive eccentric mass involving the terminal ileum and lymphadenopathy (LAP) along the portal caval space. She was diagnosed with stage IIIc adenocarcinoma colon with K-RAS wild type. A right hemicolectomy was performed. Patient received various regimen of adjuvant chemotherapy for 15 months. The disease gradually progressed to stage IV, with metastasis to liver, mesentery and retroperitoneal LAP. Meanwhile patient was diagnosed with Lynch syndrome with genetic testing positive for MSH-6 and EGFR/CEP7 2.47. She was started on pembrolizumab. The repeat CT scan of abdomen after five weeks of the first dose of pembrolizumab showed new and enlarging metastatic disease. Previous 51 × 48 mm metastatic lesion now measures 76 × 66 mm along with worsening of retroperitoneal and mesenteric LAP. As this could be pseudo progression, patient received two more doses. The CT scan of the abdomen revealed persistently enlarging liver metastasis along with enlarging mesenteric and retroperitoneal LAP. Further treatment was held. Unfortunately, patient deceased in few weeks after receiving the third dose of pembrolizumab due to HPD.

DISCUSSION:
Definition, incidence, pathogenesis and predictive factors of HPD are yet to be understood. Studies are available where parameters like tumor growth rate, tumor growth kinetic and time to treatment failure were used to define HPD, but no universally accepted definition exist. In the first study of HPD by Champiat in 2016, HPD was defined as a progression by RECIST criteria at first evaluation with a greater than or equal to two-fold increase in TGR from baseline (before treatment). Studies showed an association of HPD with age >65 years, MDM2/MDM4 amplification and EGFR alteration. Further knowledge about the pathogenesis and predictive factors of HPD may help to better understand the group of individuals that will likely benefit.
1565 Goblet Cell Carcinoid: An Unusual Presentation of Acute Abdominal Pain
Authors: Lakhani Komal , Bergagnini Isabella , Hogan Dan , Kesar Varun , Swaminath Arun 
Published: October 2019

INTRODUCTION:
Goblet Cell Carcinoid (GCC) is a rare neoplasm comprising 0.3-0.9% of appendectomy specimens and less than 14% of all malignant masses of the appendix. While abdominal pain is a common presenting complaint of GCC, rarely does it manifest as an acute perforated appendicitis, as depicted in the case below.

CASE DESCRIPTION/METHODS:
A 66 year old male with a medical history of hypertension, heart failure, endocarditis, chronic alcoholic pancreatitis presented with RLQ pain 3 days prior with associated fevers, chills, nausea, vomiting and maroon colored stools. His vitals were stable with exam notable for diffuse lower abdominal tenderness and no rebound tenderness. Labs demonstrated a mild leukocytosis of 11.7 and negative blood cultures. CT abdomen and pelvis revealed a small appendiceal abscess and acute appendicitis for which he was treated with intravenous fluids and antibiotics, then was discharged on day 3 with oral antibiotics. 7 days later, he was readmitted with intractable nausea and vomiting. Repeat CT revealed mild improvement in acute appendicitis with labs notable for a leukocytosis of 14 for which he was restarted on antibiotics. Six days later, he underwent a laparoscopic appendectomy as repeat CT was concerning for persistent appendicitis with necrosis (Figure 1). Intra-operatively, the appendix was found to be ruptured. Pathology of appendiceal specimen revealed GCC (Figure 2). His hospital course was also complicated by septic shock and respiratory failure requiring intubation, and acute tubular necrosis requiring hemodialysis. The patient eventually improved and underwent a staging right hemicolectomy which identified lymphovascular invasion and node positivity (Figure 3).

DISCUSSION:
GCC, a rare appendiceal malignancy of both neuroendocrine and glandular histological features, accounts for less than 5% of all primary tumors of the appendix. Presentation varies from no symptoms to overt gastrointestinal bleeding, with acute appendicitis as the most common initial manifestation. While GCC is of a more aggressive phenotype compared to its benign carcinoid tumor counterpart, prognosis is generally favorable. However in 15-30% of cases, metastasis to the ovaries, pelvis, abdominal cavity, ribs, vertebra and lymph nodes has been observed. Surgery is typically the treatment of choice with tumors <2 cm confined to the appendix requiring only an appendectomy. For larger tumors with nodal involvement, right hemicolectomy within 3 months after appendectomy followed by chemotherapy is warranted.
1570 A Less Recognized Cause of Checkpoint Inhibitor-Induced Diarrhea
Authors: Javed Saad , Al-Obaid Lolwa , Farwell Kristen 
Published: October 2019

INTRODUCTION:
Immune checkpoint inhibitors (ICPIs) are increasingly being used for the treatment of a number of malignancies. These immunomodulatory antibodieshave substantially improved the prognosis for patients with advanced cancers. ICPIs have been associated with immune-mediated colitis causing diarrhea and often hematochezia, with significant inflammation on endoscopic evaluation. We present an unexpected adverse event in a patient being treated with an ICPI.

CASE DESCRIPTION/METHODS:
A 58-year-old male with stage-4 lung adenocarcinoma, on pembrolizumab presented with abdominal pain, nausea and diarrhea. His symptoms had been ongoing for 6 months. He endorsed 10 lb weight loss over two months. He had completed his 22nd cycle of pembrolizumab 1 week prior to presentation. On examination, he was tachycardic and had mild tenderness in bilateral lower quadrants. Labs revealed Hgb of 19 g/dl, BUN 26, with a mild hyponatremia. He had mild leukocytosis and a CRP of 73.8 mg/L. Infectious work up was negative and the patient started loperamide. Colonoscopy revealed a normal appearing mucosa without evidence of mucosal inflammation or ulceration. Pembrolizumab was held and he was started on IV methylprednisolone with improvement in the frequency of his bowel movement. He was discharged home on an oral prednisone. Pathology from the random biopsies demonstrated surface epithelial damage with increased intraepithelial lymphocytes without significant crypt distortion, consistent with lymphocytic colitis. The patient was switched from prednisone to budesonide because of the lower rate of response associated with prednisone. He completed a taper with resolution of his symptoms.

DISCUSSION:
ICPIs are associated with a unique spectrum of side effects termed immune-related adverse events. Diarrhea is a common clinical complaint in patients this patient population, with immune-mediated colitis being a common cause. Typically endoscopic and histopathological features of immune checkpoint inhibitor-induced colitis are similar to inflammatory bowel disease (IBD) flare rather than microscopic colitis as seen in this case. The data on clinical, endoscopic, and histologic characteristics as well as management strategies for immune checkpoint induced microscopic colitis, is limited. Our case, suggests a unique form of gastrointestinal toxicity associated with pembrolizumab (PD-1 blocker) and highlights successful management with IV and oral corticosteroids, which permitted the patient to continue pembrolizumab without interruption.
1573 Ixekizumab-Induced Gastritis and Colitis in an Elderly Female With Plaque Psoriasis
Authors: Imam Zaid , Patwardhan Soumil , Qu Zhenhong , Ghaith Gehad 
Published: October 2019

INTRODUCTION:
Psoriasis and inflammatory bowel disease (IBD) share common pathogenesis pathways including cytokine mediated inflammation. Interleukin-17 (IL-17) monoclonal antibodies such as ixekizumab have demonstrated excellent results in moderate to severe plaque psoriasis and psoriatic arthritis. Antagonism of IL-17 has been demonstrated in animal models to induce or worsen existing inflammatory colitis. We hereby present a case of ixekizumab-induced gastritis and colitis in a 63-year old Caucasian female with severe plaque psoriasis successfully treated with prednisone.

CASE DESCRIPTION/METHODS:
A 63-year old Caucasian female with history of severe plaque psoriasis and peptic strictures presented with severe bloody diarrhea, generalized abdominal pain, and tenesmus few weeks after receiving 3 doses of ixekizumab. She had no personal or family history of IBD. Her medications included 81-mg ASA, omeprazole, metoprolol, cetirizine and levothyroxine. She denied NSAID use. A colonscopy 2-years prior showed two tubular adenomas, and a gastroscopy 3 months prior to ixekizumab therapy was normal. Her diagnostic evaluation revealed (a) normal CBC, kidney function and liver chemistries, (b) negative stool cultures, microscopy and C. Difficile testing, (c) a gastroscopy demonstrating diffuse gastritis involving the body and antrum (d) a flexible sigmoidoscopy demonstrating a diffuse area of atrophic, eroded and friable mucosa with contact bleeding and thickened mucosal folds in the recto-sigmoid colon. Gastric and colonic biopsies demonstrated focal mucosal erosions with architectural distortion concerning for a drug induced gastritis and colitis. H. Pylori testing was negative. Ixekizumab was discontinued and treatment with IV steroids was started. Symptom resolution was noted by day five of therapy and she was converted to an oral steroid taper.

DISCUSSION:
The temporal association, the histology and the improvement with discontinuation of the medication strongly support the diagnosis of a drug induced colitis. This case is unique in the sense that it is the first in the literature to report ixekizumab-induced gastritis and colitis. Whether the patient will require long-term immunosuppression and will manifest later with IBD is to be observed. Despite the rarity of colitis associated with IL-17 inhibitors, counseling patients on this severe adverse effect is integral to the discussion between specialists and their patients prior to initiating therapy.
1574 An Unusual Finding of Non-Hodgkin's Lymphoma in the Gastrointestinal Tract
Authors: Gangireddy Mounika , Shrimanker Isha , Goel Siddharth , Vanjarapu Jagan , Charan Mohan , Nookala Vinod 
Published: October 2019

INTRODUCTION:
Primary gastrointestinal lymphomas include a small proportion of gastrointestinal cancers but rarely involve the ileocecal valve. Even though early detection and diagnosis is prudent in the care as it is associated with favorable therapeutic options, diagnosis with colonoscopy requires a high suspicion and precision. We report an unusual presentation of B-cell lymphoma at the ileocecal valve diagnosed on colonoscopy.

CASE DESCRIPTION/METHODS:
A 55-year-old female with no significant past medical history presented with a positive fecal occult blood test at her primary care office. Her brother was recently diagnosed with colon cancer at the age of 58. Physical examination was unremarkable and laboratory tests revealed mild iron-deficiency anemia with hemoglobin of 11 gm/dl. Colonoscopy revealed a tubular adenoma in the ascending colon. Colonoscopy is done after five years revealed a prominent ileocecal valve. Histopathological examination of the biopsy showed diffuse infiltration of mononuclear cells with large malignant cells along with pleomorphic vesicular nuclei and prominent nucleoli. A diagnosis of malignant follicular B type lymphoma was made and the patient is scheduled for treatment with an oncologist.

DISCUSSION:
Gastrointestinal non-Hodgkin's lymphomas are usually detected in the stomach and duodenum. As per our knowledge, this is the first case of B-cell lymphoma involving the ileocecal valve with no major derangement or deformity on the macroscopic exam. Clinicians must be wary of the clinical presentation and consider the possibility of a primary lymphoma at the ileocecal valve with minor changes in appearance, especially in patients with a family history of malignancy.
1582 A Case of Complicated Diverticulitis Masquerading as Crohn's Disease: A Diagnostic Dilemma
Authors: Bhardwaj Gaurav , Nawaz Waqas , Hertan Hilary 
Published: October 2019

INTRODUCTION:
Diverticular disease can have a complicated course in patients younger than 40 years of age and may mimic Crohn's disease (CD), thus presenting a diagnostic challenge. We report a case of a young adult presenting with complicated diverticulitis which was initially mistaken as CD.

CASE DESCRIPTION/METHODS:
A 31 year old man was admitted for left flank pain for 6 months and a flank mass for a week associated with weight loss, fever and fatigue. Exam showed a tender palpable mass in the left flank. Initial laboratory data showed leukocytosis of 13.7 k/uL with elevated ESR and CRP. Inflammatory bowel disease (IBD) serology was consistent with CD. Abdominal CT showed mural thickening of the descending and sigmoid colon with multiple fistulae extending into the left flank muscles and a diagnosis of CD was suggested by radiology. Colonoscopy showed erythematous mucosa in the descending colon with normal terminal ileum and biopsy showing stromal fibrosis with lymphoid aggregates. CT guided incision and drainage (I&D) was performed and patient was treated with antibiotics. Within 4 weeks of his discharge he had a similar presentation requiring repeat I&D. The clinical presentation, patient's young age, positive serology and radiological findings led to a presumptive diagnosis of CD. Infliximab was started but he continued to have hospitalizations for recurrent retroperitoneal abscesses. Finally, a left hemicolectomy was done. Pathology showed acute and chronic diverticulitis with mural scarring and abscess formation without any evidence of granulomas, ulcerations and crypt abscesses to suggest IBD.

DISCUSSION:
Diverticular disease has been described as not only rare but virulent in young patients. 25% of patients with diverticulitis develop complications including perforation, fistulae, obstruction or a stricture which can mimic CD. Although a common site of involvement in diverticulitis, the sigmoid colon is also involved in 70% of cases in Crohn's colitis. Radiologic findings can mimic the features of CD in complicated diverticulitis. IBD serology can be misleading due to its low specificity. Histologically, granulomas are only seen in 30% of cases in CD. No response to CD therapy can sometimes be the only clue to review the diagnosis. Differential may also include segmental colitis associated with diverticulosis that can develop into CD. This case highlights the virulent course of diverticulitis in young patients and serves as a reminder to have a high index of suspicion in this population.
1583 Atypical Presentation of Calcified Fecalith
Authors: Hoskere Dhanush , Ramasamy Kovil , Dedousis John 
Published: October 2019

INTRODUCTION:
Fecaliths are generally classified by the degree of calcification and presence of solid material in the stool. Fecaliths can cause complications such as hemorrhage, perforation, intussusception, and bowel obstruction. However, no documented cases of solid fecaliths associated with diarrhea exist.

CASE DESCRIPTION/METHODS:
63-year-old male with past medical history of hypertension, diabetes mellitus type II, gastroparesis, chronic kidney disease, and hyperlipidemia presented to the hospital with subjective fever, dull epigastric pain, belching, episodes of non-bloody and non-bilious vomiting, and non-bloody diarrhea for 2 weeks. He denied any recent travel history, new food consumption, or alcohol use. On exam, patient had diffuse tenderness of the abdomen but did not have any guarding, rebound, or distension. Lipase and liver function tests were within normal limits. Abdominal CT revealed no evidence of bowel incarceration or obstruction. Colonoscopy was performed for further evaluation which showed a large polyp covered with stool prolapsing into the cecum. Stool was removed with irrigation, which exposed a solid egg-shell like calcification. The calcification was cold-snared to expose the normal colonic mucosa underneath and was subsequently removed. This egg-shell like calcification likely represented fecalith which had calcified around a mucosal fold in the cecum. After the endoscopy, patient's symptoms improved, and he was discharged from the hospital.

DISCUSSION:
Fecaliths are common in clinical practice. The hardness of a fecalith is usually classified by the degree of calcification and presence of solid materials. Usually, fecaliths are managed conservatively with digital disimpaction, low residue diet, and administration of enemas and laxatives. Fecaliths can be broken down with colonoscopic methods such as a water jet or mechanical lithotripsy prior to removal. In this case, water jet only cleaned the liquid stool off of the calcified fecalith. This is one of the first cases reported using cold snare to break and dislodge calcified fecalith. It is also one of the first cases where fecalith was shaped around mucosa forming an egg-shell like calcification. In addition, fecaliths have been known to cause constipation through bowel obstruction; however, this case shows that there may also be an association with diarrhea as fecaliths may cause irritation of the mucosa leading to increased colonic transit. Further research will have to be done to assess for the validity of this theory.
1585 Chronic Constipation With Massive Acquired Megacolon in a 19-Year-Old Man
Authors: Abadir Alexander P. , Rombaoa Christopher , Park Sunhee 
Published: October 2019

INTRODUCTION:
Acquired megacolon is a rarely diagnosed condition that may be a source of significant distress in the acutely hospitalized patient. It presents in either gender at any age. Symptoms, when present, are typically abdominal pain with distention, gas distress, and constipation. Reported cases are typically less than 10 cm on diagnostic imaging. Pathology findings vary greatly and include muscularis hypertrophy or degeneration of the smooth muscle, damaged or reduced ganglia, melanosis coli, or chronic inflammation.

CASE DESCRIPTION/METHODS:
A 19-year-old Hispanic US-born man presented to the ER with severe, progressively worsening abdominal pain and distention for one month and inability to urinate. His last bowel movement (BM) was 3 weeks ago, small and liquid. He stated it was common for him to not have a BM for up to a month. This has occurred since he was six years old, when he began avoiding defecation due to pain he experienced when moving his bowels. Prior treatment with laxatives and enemas had been ineffective in inducing regular bowel movements. He has had difficulty gaining weight. Initial labs were significant for severe iron deficiency anemia with MCV 65, Ferritin 2, TIBC 301, Iron 11, and percent saturation of 4%. CT imaging showed a markedly distended colon and rectum measuring up to 17 cm in the sigmoid colon. There was severe stool burden in the rectum and the distended colon. The colon was causing mass effect and crowding of other organs, including a distended bladder. Initial inpatient management with enemas, disimpaction, and frequent laxatives failed to cause significant reduction in the colonic distention. Under anesthesia, rectal examination found normal rectal tone and required disimpaction and lavage. Full-thickness rectal biopsies were obtained which revealed mild erosion, indeterminate colitis, and hyperplasia of the muscularis mucosa. Calretinin was positive for nerve fibers, however no ganglia were seen. A diverting Brooke ileostomy was created without immediate complications. On 1 month follow up the patient reported significant weight gain, no further abdominal pain, and adequate ostomy output.

DISCUSSION:
This case demonstrates a severe example of acquired megacolon in a young man due to chronic constipation. Surgery is typically required for very distended cases, but surgical options vary considerably and have been poorly studied. In this patient, due to the extreme nature of his megacolon, surgical diversion was performed to allow eventual resection.
1586 A Classic Presentation of Cowden Syndrome
Authors: Hanna David , Pedroso Claire , Pluskota Christopher , McKee Jessica 
Published: October 2019

INTRODUCTION:
Cowden syndrome (CS) is a rare autosomal dominant hereditary multiple hamartoma syndrome characterized by benign and malignant tumors. CS is one of the four subtypes of phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS). The National Comprehensive Cancer Network utilizes consensus diagnostic criteria, where one must have ≥3 major criteria or 2 major plus 3 minor criteria. Major criteria include breast cancer, endometrial cancer, follicular thyroid cancer, GI hamartomas including ganglioneuromas, Lhermitte-Duclos disease, macrocephaly, macular pigmentation of the glans penis, and multiple mucocutaneous lesions. Minor criteria include autism, colon cancer, esophageal glycogenic acanthoses, lipomas, intellectual disability, renal cell carcinoma, testicular lipomatosis, papillary thyroid cancer, thyroid structural lesions, and vascular anomalies.

CASE DESCRIPTION/METHODS:
A 59-year-old male with macrocephaly presented for a screening colonoscopy. He was found to have 30 polyps ranging in size from 3-15 mm. Pathology revealed serrated adenomas, hyperplastic polyps and moderately differentiated invasive adenocarcinoma arising in a tubular adenoma. Subsequent PET/CT revealed marked enlargement and heterogeneity in the thyroid gland. He underwent a total colectomy with ileorectal anastomosis and ultimately a total thyroidectomy. The resected colon showed adenomatous polyps, multiple lipomas, and a ganglioneuroma. Pathology from the thyroid revealed a 2.5 cm nodule with follicular carcinoma and a 6 mm nodule with papillary micro-carcinoma, follicular variant. Our patient met 3 major criteria (macrocephaly, GI hamartomas including ganglioneuromas, follicular thyroid carcinoma) and 1 minor criterion (colon cancer). The clinical presentation prompted genetic testing.

DISCUSSION:
Early onset colorectal cancer has been reported in patients with CS due to malignant transformation of adenomatous and hamartomatous polyps. Management includes annual thyroid ultrasound, renal ultrasound at age 40 every 1-2 years, dermatologic assessment, and discussion regarding risk to relatives. Colonoscopy is recommended at age 35 and then at least every 5 years; more frequent in patients who are symptomatic, have family history of colon cancer, personal history of polyps or colon cancer. Recognition of pertinent medical history, family history and physical manifestations are critical for accurate diagnosis, risk assessment, genetic testing and medical management.