An early Cambrian polyp reveals an anemone-like ancestor for medusozoan cnidarians

Extant cnidarians are a disparate phylum of non-bilaterians and their diploblastic body plan represents a key step in animal evolution. Anthozoans (anemones, corals) are benthic polyps, while adult medusozoans (jellyfishes) are dominantly pelagic medusae. A sessile polyp is present in both groups and is widely conceived as the ancestral form of their last common ancestor. However, the nature and anatomy of this ancestral polyp, particularly of medusozoans, are controversial, owing to the divergent body plans of both groups in the extant lineages and the rarity of medusozoan soft tissues in the fossil record. Here we redescribe the enigmatic Conicula striata Luo et Hu from the early Cambrian Chengjiang biota, south China, which has previously been interpreted as a polyp, lophophorate or deuterostome. We show that C. striata possessed features of both anthozoans and medusozoans. Its stalked polyp and fully encasing conical, annulated organic skeleton (periderm) are features of medusozoans. However, the gut is partitioned by ~28 mesenteries, and has a tubular pharynx, resembling anthozoans. Our phylogenetic analysis recovers C. striata as a stem medusozoan, indicating that the enormously diverse medusozoans were derived from an anemone-like ancestor, with the pharynx lost and number of mesenteries reduced prior to the origin of crown group Medusozoa.

A RARE CASE OF COLON CANCER IN A YOUNG PATIENT: A CASE REPORT AND LITERATURE REVIEW

Malignant neoplasms of the colon and rectum are often missed in patients younger than 45 years, the uncertainty of the diagnosis by the surgical team due to unavailability of clear screening guidelines in this population may be one of the reasons. The objective of this case report is to highlight the occurrence of colon cancer in a patient younger than 45 years to avoid the delay in management and the need for clear screening guidelines. Our patient, a 30 years old lady with an average risk of colon cancer demonstrated clinical symptoms and signs suggestive of partial bowel obstruction. After full radiological and laboratory investigations, she was initially diagnosed with inflammatory vs infectious cause of this obstruction. Colonoscopy showed a mass in the right hepatic flexure and sessile polyp in the transverse colon, Histopathology result showed moderately differentiated colon cancer. The patient was taken to the operation theater, right extended hemicolectomy was done, final histopathology result showed stage IIIc cancer, the patient was sent for oncology. In a conclusion, Colon cancer in patients younger than 45 years old requires a high index of suspicion by the surgeon and the managing team despite the unavailability of clear guidelines for screening at a young age.

Granular cell tumour of cecum mimicking a neuroendocrine tumor

Granular cell tumor (GCT) is a benign soft tissue neoplasm generally believed to be of nerve sheath origin. It is most frequently seen in skin, subcutaneous tissue and oral cavity. GCTs are uncommon in gastrointestinal tract (GIT), in which the majority are located in the esophagus. In this article, we report a case of GCT involving cecum in a 22 years lady. She had a sessile polyp in the cecum which was thought to be NET. Typical histomorphology and expression of S-100 on immunohistochemistry confirmed the diagnosis.We have reviewed, the GCTs of cecum reported previously with emphasis on the differential diagnosis. To best of our knowledge, this is only the 3 case of GCT of cecum reported in the Indian literature. Colonic GCTs are extremely uncommon. This is just the third case of GCT of colon in Indian literature. GCTs pose a diagnostic challenge due to lack of symptoms or nonspecific symptoms. Awareness of this entity helps in preventing misdiagnosis as happened in this case and avoiding further unnecessary treatment.

Gastric Neuroendocrine Tumor

Gastric neuroendocrine tumor (gNET) is a rare carcinoid of the stomach whose incidence is increasing due to widespread use of upper gastrointestinal endoscopy (UGIE). There are four types of gNETs with different management strategies and prognosis. Here, we present a patient who came with abdomen pain and intermittent melena. UGIE showed a sessile polyp in the stomach. The patient subsequently underwent polypectomy and was symptomatically relieved.

Duodenal-Type Follicular Lymphoma: A Newly Recognized Entity in the 2016 World Health Organization Classification Update

Introduction/Objective Most cases of primary follicular lymphoma (FL) in the gastrointestinal tract occur in the second part of the duodenum, presenting with multiple small polyps. Duodenal type follicular lymphoma (D-FL) is a newly recognized entity in the 2016 WHO classification update. Methods Upper endoscopy in a 72 year old female with iron deficiency anemia revealed a single 8 mm sessile polyp with no bleeding in the duodenal bulb. Histology revealed dense infiltrate of small mature lymphocytes with a nodular growth pattern. Follicles, composed predominantly of centrocytes with scattered centroblasts, diffusely expressed CD20, CD10 and BCL-2. Results This immunoprofile characterizes follicular lymphoma. Real-time polymerase chain restriction assay detected BCL-2 MBR/JH DNA fusion sequence, usually resulting from t(14;18)(q32;q21) translocation and confirming D-FL. D- FL is often asymptomatic, discovered incidentally at endoscopy. It is usually low grade (grade 1–2), presenting at low stage, with immunophenotype and t(14;18)(q32;q21) similar to other FLs. However, in comparison to nodal FL, D-FL has higher selective use of V4 and V5 immunoglobulin heavy chain gene rearrangements, which has been linked to antigen dependent mechanisms in lymphoma development; this feature is shared with Mucosa-Associated Lymphoid Tissue (MALT) lymphoma. Conclusion D-FL often remains localized to the small bowel and has a good outcome even with local small bowel recurrences. It has a long term survival of >12 years. There is a low (<10%) risk of progression to nodal disease and given the indolent clinical course, a watch-and-wait approach is reasonable for most patients.

Colonic lipoma presenting with intussusception

Colonic lipomas are rare benign tumours, although they constitute the most common non-epithelial neoplasm of the gastrointestinal tract. They mostly remain asymptomatic and rarely present with intussusception. A 62-year-old male presented with acute intestinal obstruction. On laparotomy, intussusception of the descending colon was detected, with a single sessile polyp measuring 3 cm×3 cm as the lead point. A left hemicolectomy was performed, and histopathological examination revealed a lipoma of the colon.

Duodenal gangliocytic paraganglioma: a rare case report

Background Gangliocytic paraganglioma (GP) is quite rare, and origin and entity remain to be elucidated. Case presentation A 51-year-old male presented with a sessile polyp with smooth surface measured about 1cm in diameter in the descending portion of duodenum. Pathological examination displayed a neoplasm located in submucosa, infiltrating into lamina propria. The tumor consisted of epithelioid, ganglion-like and spindle cells admixing in a haphazard way. The epithelioid cells resembled paraganglioma in cytological and architectural features, the ganglion-like cells was scattered, and the spindle cells resembled neurofibroma. Syn, MAP-2 and CgA were positive in the epithelioid and ganglion-like cells in variety and NF highlighted the ganglion-like cells. S-100 and SOX-10 were positive in the sustentacular cells around the epithelioid cells and spindle cell proliferation. PR was also positive. Conclusions Origin of GP is presumed to be related with pancreas islet. GP is supposed to be distinguished with NET G1 and designated as paraganglioma-ganglioneuroma, a kind of composite paraganglioma.

Glomus Tumor of the Colon: A Rare Case Report and Review of Literature

Glomus tumor is a rare mesenchymal neoplasm originating from the modified smooth muscle cells of the glomus body. Primary colonic glomus tumor is extremely rare with only 5 cases published in the English literature. In this article, we report the sixth case of primary colonic glomus tumor in a 50-year-old female with no significant past medical history who presented with routine screening colonoscopy. The entire colon was endoscopically unremarkable except an incidental 6-mm sessile polyp located in the descending colon. Biopsy showed a densely cellular neoplasm composed of small, bland, slightly spindled to predominantly epithelioid cells with clear to eosinophilic cytoplasm arranged in nests and sheets. The tumor cells were interspersed with slit-like thin-walled vessels and scattered short nerve bundles. Immunohistochemically, the tumor cells were positive for smooth muscle actin, h-caldesmon, and CD34 (focal), but completely negative for HMB45, S100, EMA, desmin, DOG-1, and CD117. The histologic features and immunohistochemical profile supported a diagnosis of primary colonic glomus tumor. The patient was asymptomatic and disease free after the procedure.

A105 ENDOSCOPIC MUCOSAL RESECTION (EMR) OF LARGE SESSILE POLYPS: DATA FROM A MULTI-CENTER HEALTH ZONE

Background EMR is the standard of care for management of large non-invasive colonic polyps. Current guidelines recommend repeat colonoscopy within 6 months after EMR of large sessile polyps to assess the EMR site for residual adenoma. We reviewed the outcomes and compliance to these guidelines in patients at the University of Alberta Hospital (UAH) and surrounding 7 hospitals. Aims The primary outcome was the proportion of patients who received a follow up colonoscopy within 180 days. Methods Retrospective data was collected on consecutive patients who had a large polyp resection (size >2cm as documented per endoscopy report) from January 1st, 2014 to January 1st, 2016. Information was collected on patients from UAH as well as seven surrounding hospitals within the Edmonton geographic zone. Data was extracted from electronic health records. Results Of 258 patients identified patients, 250 had complete data. Of these 250 patients, 151 (60.4 %) were male and median age was 67 (IQR 60 - 72). Eighty-two cases (32.8%) were performed at UAH, with 168 cases (67.2%) at other hospitals. Polyps were removed by gastroenterologists (n=215, 86.0%), surgeons (n=26, 10.4%), and others (n=9, 3.6%). Fifty-two patients (20.8%) had no formal follow up on electronic health records, while 198 patients (79.2%) had a repeat colonoscopy. 57 patients (29.1 %) had a repeat colonoscopy within 180 days. The median follow-up time was 224 days (IQR 172–365). Of the 82 cases performed at UAH, 74 (90.2%) had follow up. Out of the 168 cases at the other hospitals, 124 (73.8%) had follow up (p<0.01). Sixteen (21.9%) and 41 (33.3%) cases were followed up within 180days at UAH and other hospitals, respectively (p=0.09). Of the 74 cases with follow up at UAH, 12 (15.7%) had residual tissue confirmed by pathology. Of the 124 cases at other hospitals, 26 (21.0%) had follow up (p=0.41). Median polyp size was 2.5cm (IQR 2.0cm - 3.5cm) Conclusions Only 29.1% of patients with large sessile polyp removal in the Edmonton zone had a repeat colonoscopy within 180 days. Patients with large polypectomy performed at the academic hospital were more likely to be followed up compared to non-academic hospitals. Further validation studies with larger data sets are needed. These findings highlight the need for standardized pathways to appropriately manage and survey large polyps post-EMR. Funding Agencies None

A Preoperative Scoring System to Predict Carcinoma in Patients with Gallbladder Polyps

Introduction: A preoperative scoring system to predict carcinoma in patients with gallbladder polyps (GBPs). Methods: Preoperative parameters of patients with GBPs who underwent cholecystectomies were used to construct a scoring system to ascertain the risk of malignancy (reference group). The scoring system developed from this approach was applied to the validation group. Results: In the reference group, 11.5% of patients had carcinomas, in whom the median age was 68 years and the polyp size was 16.9 mm. According to the univariate analysis, the significant factors for carcinoma were age ≥65 years, the presence of gallstones, polyp size ≥13 mm, solitary polyp, and sessile polyp. Age ≥65 years and polyp size ≥13 mm were significant factors according to the multivariate analysis. From these results, we developed a preoperative scoring system to predict carcinoma. The patients were divided into 1 of 2 groups: low-risk and high-risk and their malignancy rates were 4.1 and 61.1% respectively (p < 0.001). In the validation group, the malignancy rate was higher for those in the high-risk group (p = 0.016). Conclusions: The proposed preoperative scoring system based on simple clinical variables appears to be useful for predicting malignancy in patients with GBPs.