Small intestinal ulceration secondary to carcinoid tumour arising in a Meckel's diverticulum

Epidemiology of Large Bowel Carcinoid Tumors in the USA: A Population-Based National Study

BACKGROUND AND AIMS

Prior studies have shown that about 90% of all carcinoid tumors occur in the GI tract. However, epidemiological studies of these tumors have been limited by small sample size. Our aim was to obtain a more robust epidemiologic survey of large bowel carcinoids (LBC), using population-based data in order to more accurately identify risk factors for these tumors.

METHODS

We used a commercial database (Explorys Inc, Cleveland, OH) which includes electronic health record data from 26 major integrated US healthcare systems. We identified all patients aged 18 and older who were diagnosed with LBC, excluding appendiceal carcinoids, between 1999 and 2018 based on Systematized Nomenclature Of Medicine-Clinical Terms (SNOMED-CT) and evaluated the prevalence of LBC. We also performed univariate analysis to describe age-, race-, and gender-based distributions and to identify potential risk factors.

RESULTS

Of the 62,817,650 individuals in the database, 4530 were identified to have LBC with an overall prevalence of 7.21/100,000. Individuals with LBC were more likely to be elderly (age > 65) [OR 2.17, CI 2.05-2.31, p < 0.0001], smokers [OR 3.25; 95% CI 3.00-3.53, p < 0.0001], have a history of alcohol use [OR 3.75; 95% CI 3.52-3.99, p < 0.0001], diabetes mellitus (DM) [OR 4.42; 95% CI 4.14-4.72, p < 0.0001], obesity [OR 1.58; 95% CI 1.43-1.74, p < 0.0001], family history of cancer [OR 8.06; 95% CI 7.47-8.71, p < 0.0001], and personal history of ulcerative colitis [OR 6.93; 95% CI 5.55-8.64, p < 0.0001] or Crohn's disease [OR 6.45; 95% CI 5.24-7.95, p < 0.0001]. The prevalence of LBC was less among Caucasians compared to African-Americans [OR 0.57; 95% CI 0.53-0.61, p < 0.0001]. There was no statistically significant gender-based difference; men versus women [OR 1.02; 95% CI 0.96-1.08, p = 0.47]. The most common presenting symptoms included flushing, diarrhea, nausea, weight loss, and abdominal pain, while the most common GI associations included perforation, obstruction, hemorrhage, intussusception, and volvulus.

CONCLUSION

This is the largest epidemiological study evaluating the prevalence of LBC. We estimated the prevalence rate of LBC to be 7.21/100,000. The presence of significant risk factors with the clinical picture suspicious for a LBC should warrant thorough evaluation as these tumors can lead to life-threatening complications. Further studies are needed to better understand the mechanism of association between these risk factors and LBC.

A Case of Carcinoid of Meckel's Diverticulum Associated with Gastric Adenocarcinoma

Meckel's diverticulum is an uncommon gastrointestinal congenital anomaly that occurs in 1-3% of the population. It is sometimes associated with complications related to the presence of ectopic tissue (obstruction, ulceration, hemmorhage, inflammation, perforation, fistula and tumors). Neoplastic degeneration of Meckel's diverticulum mucosa is rare, developing in only 1-5% of all diverticula, usually asymptomatic and occasionally discovered. Disease is metastatic, usually to the liver, in 25% of cases. We report a case of asymptomatic unsuspected carcinoid of Meckel's diverticulum with ileal, hepatic and mesenteric metastasis discovered during a gastrectomy performed for gastric adenocarcinoma. The patient underwent ileal and Meckel diverticulum resection, excision of mesenterial metastasis and liver bisegmentectomy. Furthermore, total gastrectomy with esophago-jejunal anastomosis was performed. After an 18-month follow-up period, the patient is alive and disease free. Owing to possible neoplastic degeneration, Meckel's diverticulum should be resected when occasionally discovered. In the presence of a carcinoid tumor, even if associated with metastatic disease, extended resection is recommended.

An intestinal neuroendocrine tumour associated with paroxysmal ventricular tachycardia and melaena in a 10-year-old boxer

A 10-year-old female neutered boxer was presented with a five-week history of episodic collapse and melaena. Twenty-four-hour electrocardiograph (Holter) analysis revealed the collapsing episodes to coincide with episodes of paroxysmal ventricular tachycardia. Investigation of the dog's melaena revealed a gastric ulcer which was treated medically and an ileocaecal mass which was surgically excised. Histopathological examination of the mass was consistent with a neuroendocrine (carcinoid) tumour. The patient's recovery after surgery was unremarkable. At six-week follow-up, there had been no further episodes of melaena or collapse and repeat Holter analysis did not show any significant abnormalities. In this dog the gastric ulceration and paroxysmal ventricular tachycardia could be attributed to a paraneoplastic syndrome as a result of circulating vasoactive substances released by the tumour; this is supported by the evidence that all clinical signs resolved after surgical excision of the mass and the dog was clinically well 18 months after surgery.