Abstract

Gastric carcinoid tumours are rare lesions but have been the focus of much scientific investigation. The incidence of gastric carcinoid appears to be increasing without a corresponding increase in survival, despite utilization of the latest available therapies. We present a case of 50 years old male who was diagnosed as gastric adenocarcinoma on endoscopic biopsy. Patient underwent palliative partial gastrectomy with transverse colectomy along with gastrojejunostomy and colostomy as tumour was invading transverse colon. Histopathology report of the specimen revealed malignant carcinoid of stomach extending into the serosa of transverse colon along with adenocarcinoma i.e. collision tumour. We discuss the presentation and treatment modalities of these tumours so that patients can be treated adequately.

Introduction

Gastric carcinoma compromise less than 1% of gastric neoplasms. They can be separated into three distinct groups based on both clinical and histologic characteristics:- type I: those associated with chronic atrophic gastritis type A (CAG-A), type II: those associated with Zollinger-Ellison (ZE) syndrome; and type III: sporadic gastric carcinoid tumour.¹

Interest in gastric carcinoid tumours has in recent time amplified considerably as the understanding of both their biological background and clinical significance has developed. The increase in identification associated with the widespread availability of upper gastrointestinal endoscopy has facilitated diagnosis.²

Adenocarcinoma is the most common malignant gastric neoplasm, whereas a gastric carcinoid is relatively uncommon, and the coexistence of adenocarcinoma and a typical carcinoid tumour is rare.³ We report a case of primary malignant gastric carcinoid with adenocarcinoma invading transverse colon.

Case Report

We present a case of 50 year old male who was referred to us from a rural hospital with history of pain in abdomen since 2 years and lump in abdomen since 6 months. On clinical examination a mobile lump in the epigastrium extending upto umbilicus was present. It was firm in consistency with nodular surface. Ultrasound suggested a gastric lump. His OGD scopy revealed an ulcer on the greater curvature. Biopsy taken from the ulcer revealed invasive adenocarcinoma. His Contrast enhanced CT scan revealed a malignant growth in the stomach arising from greater curvature with perigastric lymph nodes. Patient was posted for gastrectomy. Intra-operative findings revealed a gastric malignancy arising from greater curvature of stomach and invading transverse colon with omental thickening and peritoneal metastases. In view of disseminated disease palliative partial gastrectomy with transverse colectomy (Fig. 1) followed by gastrojejunostomy and colocolostomy was done. The histopathological examination of the resected tumour revealed the concurrent presence of moderately differentiated adenocarcinoma and a typical carcinoid tumour, which had a colliding pattern of tissue proliferation. There was no intermixing or transition area between the two components. The final pathologic diagnosis was collision tumour of the adenocarcinoma and carcinoid tumour and extending to the serosa of the transverse colon with mesenteric lymph nodes showing metastasis. Post-operative course was uneventful. Patient refused chemotherapy. His follow up of six months has shown him to be symptom free. This is a unique case of gastric carcinoid with gastric adenocarcinoma invading transverse colon.

Discussion

Gastric carcinoid (GC), which was a rare entity earlier, is seen more often nowadays due to aggressive endoscopic surviellance.1 It is of three types and we discuss here type III carcinoid. Gastric carcinoid in recent studies have been reported in a higher frequency, with these constituting 10-30% of all carcinoid tumours.4 Several Indian studies have shown an increase in diagnosis of GC, similar to reports from Western countries. The rise is in the proportion of GC associated with atrophic gastritis. Whether this reflects a higher frequency of detection due to more endoscopic biopsy sampling or due to some other reason needs investigation.4

Between 15-25% of gastric carcinoids are sporadic i.e. type III. In contrast to type I and type II carcinoids, these lesions develop in the absence of hypergastrinaemia, are usually greater than 1 cm in size, and tend to pursue aggressive clinical course.1 Sporadic carcinoid tumours have been associated with an atypical carcinoid syndrome, which is manifested primarily by flushing and is thought to be mediated by histamine. The majority of sporadic carcinoid tumours are metastatic at the time of presentation and death due to disease is frequent.1 In our case, there were no symptoms of carcinoid syndrome; however, it was metastatic at the time of presentation.1

Fig. 1 : Intra-operative figure showing specimen of stomach along with transverse colon marked with (+) and cut ends of the transverse colon marked with arrows.

The presentation in Type III is more of lump and pain than gastritis as in type I and II.1,5 Sometimes it is associated with pernicious anaemia, which presents with achlorhydria, hypergastrinaemia and haematemesis.6 In our case the patient presented with pain in abdomen and lump.

Numerous diagnostic and therapeutic modalities including endoscopic ultrasound, somatostatin receptor scintigraphy, long-standing octreotide, hepatic artery embolization, endoscopic mucosal resection and surgical resection have been the focus of recent investigations.7 In our case Ultrasound revealed gastric lump, upper GI endoscopy showed an ulcer over greater curvature. Biopsy of the ulcer confirmed adenocarcinoma of stomach. CT scan showed gastric growth with perigastric lymph node.

As the understanding of biologic basis of gastric carcinoid tumours increase, the treatments will likely be a multimodal approach tailored to individual tumour biology and will incorporate a variety of diagnostic and therapeutic modalities. There are few cases of sporadic gastric carcinoid tumour successfully treated by LADG (laparoscopy assisted distal gastrectomy). LADG may be useful for the treatment of patients with sporadic gastric carcinoid tumour and possible lymph node metastasis.8 However, in India, majority of patients present with large growth are not amenable to this modality of treatment as they present late.

Treatment of GC includes total gastrectomy, distal gastrectomy, tumour excision and endoscopic polypectomy and vitamin B12 supplementation with surviellance.4

A palliative distal gastrectomy with a partial resection of transverse colon was performed because of peritoneal dissemination found in the mesocolon and as the tumour was involving the transverse colon serosa it was wise to do a resection of transverse colon along with gastrectomy. Histopathology of the resected specimen showed concurrent presence of moderately differentiated adenocarcinoma and a typical carcinoid tumour, which had a colliding pattern of tissue proliferation. The final pathologic diagnosis was collision tumour of the adenocarcinoma and carcinoid tumour and extending to the serosa of the transverse colon with mesenteric lymph nodes showing metastasis. Before the operation, there was no evidence that the lesion was a collision tumour. Had the biopsy specimen revealed the carcinoid component, the course of treatment and surgery might have been different. Chemotherapy should be given as it was adenocarcinoma with gastric carcinoid so bleomycin with cisplatin should be given in 6 cycles. Our patient refused chemotherapy.

Composite tumour can occur in the setting of atrophic gastritis. However, in our case there was no atrophic gastritis. The findings in this patient reinforce the concept that the epithelial and neuroendocrine cells of the gastrointestinal tract both result from multidirectional differentiation of a primitive cell.9

References

1. Management of localized disease: Carcinoid tumour DANA FARBER cancer institute, Harvard Medical School, Boston. Gastric Cancer Journal 2003; 6 (4) : 62-6.
2. Modlin IM, Lye KD, Kidd M. Carcinoid tumours of the stomach. Gastrointestinal Surgical Path biology Research group, Yale University, school of medicine, New Haven, CT 06250-8062, USA. Am J Gastroenterol 1997; 92 (8) : 1378-80.
3. Yukie Morishita, et al. Collision tumour of the stomach: A rare case of an adenocarcinoma and carcinoid tumour; archives of Pathology and Laboratory Medicine: Vol. 129, No. 3, pp. 407-9.
4. Hegde V, Mohandas KM, Ramadwar M, Shukla P, Mehta S. Gastric carcinoids: a changing trend. Surg Oncol 2003; 12 (2) : 153-72.
5. Guillem P. Gastric carcinoid tumours. Is there a place for antrectomy? Curr Opin Oncol 2005; 17 (1) : 1-6.
6. Kadikoylu G, Yavasoglu I, Yukselen V, Ozkara E, Bolaman Z. Treatment of gastric carcinoid tumour by endoscopic polypectomy in a patient with pernicious anaemia. World J Gastroenterol 2006; 12 (26) : 4267-9.
   
7. Mulkeen A, Cha C. Gastric Carcinoid. Indian J Gastroenterol 2003; 22 (6) : 209-11.
   
8. Ishikawa K, Etoh T, Shiromizu A, Inmata M, Shiraishi N, Kashima K, Kitano S. A case of sporadic gastric carcinoid tumour treated successfully by laparoscopy-assisted distal gastrectomy; Dept. of Surgery I, Oita University, faculty of medicine, 1-1idaigaoka, Hasama - Machi, Oita 879-5593, Japan, Dec. 2005.
   
9. Debasis Adhikari, Charles Conte, David Eskries, Carlos Urmacher, Elen Kahn. Combined Adenocarcinoma and carcinoid tumour in atrophic gastritis, Annals of Clinical and Laboratory Science 2002; 32 : 422-7.