Multiple neuroendocrine tumor of the small bowel: a case report and a review of literature

Overview

Primary malignant tumors of small bowel constitute only about 1–2% of all gastrointestinal neoplasms. Although neuroendocrine tumors (NETs) are relatively rare, they still represent the second most common malignancy of the small bowel (after adenocarcinoma). Clinical manifestations include abdominal pain, bowel obstruction, diarrhea, weight loss and bleeding. The differential diagnosis of obscure gastrointestinal bleeding can sometimes be challenging for endoscopy as well as for radiology methods. We present the case of an 80-year-old man suffering from severe hypochromic anemia. Routine endoscopic methods did not show any appropriate pathology. Finally, a single ulcerative infiltration of the ileum was diagnosed by capsule endoscopy (CE). CT enterography did not reveal any other lesions. In accordance with a positive chromogranin A, endoscopic and radiologic methods, a suspicion of NET was expressed. During the surgery, 7 lesions were found and a resection of 120 cm of ileum was performed. The histology confirmed a diagnosis of NET grade 1, with a total number of 15 NET lesions in the specimen. The following octreotide scan did not show any residual infiltration. We present a patient with 15 NET lesions in the ileum diagnosed by CE and successfully cured by surgical resection of the ileum.

Key words:

capsule endoscopy – carcinoid syndrome – gastrointestinal carcinoids – neuroendocrine tumor – obscure gastrointestinal bleeding – small bowel – surgery

Introduction

Primary small bowel malignant tumours comprise only 1–2% of all gastrointestinal neoplasms. Neuroendocrine tumours (NETs) represent a relatively rare subgroup of malignant neoplasms. Despite this fact, NETs are the second most common malignant tumours of the small bowel [1–3]. NET can be often asymptomatic for a long time, sometimes can present with obscure gastrointestinal bleeding (OGIT) and the diagnostics can be challenging as for endoscopic as well as radiologic tools [4–7]. An increase of small bowel NETs incidence has been reported recently, not due to a real incidence rise but rather due to better diagnostic methods [6,8,9].

Case report

Our patient is an 80-year-old polymorbid man investigated for a severe anemia (hemoglobin level of 53 g/L). His case history includes chronic ischemic heart disease, heart attack, aortic valve replacement, cardiac rhythm disturbances, diabetes mellitus and prostatectomy for adenocarcinoma.

Esophagogastroduodenoscopy revealed just a mild erosive gastropathy. During colonoscopy, only diverticulosis of the sigmoid colon was diagnosed, and four small polyps were removed by endoscopic polypectomy (tubular adenomas).

Due to persistent anemia, the patient underwent enteroscopy, where no significant pathology was discovered. Subsequently, capsule endoscopy (CE) was performed, finding a 12 × 6 mm isolated ulceration in the ileum, with thickened edges giving the impression of an exulcerated submucosal formation of 2 cm in total (fig. 1a, 1b).

Due to the positive values of chromogranin A (207.3 µg/L, reference range < 50) and the findings of endoscopic and imaging methods – CT enterography (fig. 2a, 2b), we expressed a suspicion of a NET of the small intestine. During surgery (fig. 3), seven suspect rigid small intestine lesions were palpably detected, and a resection of 120 cm of the ileum was performed. According to definitive histology (fig. 4, 5, 6a, 6b), a total of 15 NET grade 1 lesions with the predominance of submucosa and muscularis propria (T3) were found. Metastases were present in 6 regional lymph nodes (total 12 examined lymph nodes). In the postoperative period, a following octreotide scan was performed without residual lesion finding. From an oncological point of view, only observation without subsequent adjuvant oncological treatment will be introduced.

Discussion

NETs located in the duodenum up to 1cm in size can be treated endoscopically and are mostly isolated lesions [10,11]. On the other hand, surgical treatment is recommended for NETs in the jejunoileum. They have a greater propensity to metastasize and NETs in this localization can even form more lesions [2,6,8]. Multiple lesions may be found in up to 40% of cases [8]. Small bowel NETs may initially behave asymptomatically, and even small tumors under 1 cm tend to form lymph node metastases relatively early (in 20–30% of cases). For NETs larger than 2 cm, the risk of metastatic involvement of regional lymph nodes increases to over 80%. With primary tumor size up to 2 cm, the incidence of liver meta­stases is reported in up to 20% of patients (for sizes greater than 2 cm in more than 40% of patients) [1,5]. The carcinoid syndrome, which occurs in 20–30% of patients with a NET of the small intestine, is almost always (around 95%) associated with the presence of liver meta­stases [4,6,8].

When diagnosing NETs, their tendency to extraluminal proliferation may be problematic. This was the case with our patient, most of whose lesions tended to infiltrate submucosa and muscularis propria. In the diagnosis of small intestine tumors, CE, double-ballon enteroscopy and CT enterography are usually compared. In comparative studies of these methods in the diagnosis of small intestine tumors, the yield appears to be similar (although in case of NETs, CE has slightly better results) [8,12–15].

On the other hand, a certain disadvantage of CE in the diagnosis of NETs may be their tendency toward extraluminal spreading [5]. The combination of these 3 methods in the diagnosis of OGIB and small intestine tumors [15–19] seems to be ideal. In our case, only one lesion was identically visible on CE and CT enterography. Other lesions were detected by palpation during surgery and from the definitive histology. The following octreotide scan did not reveal any other residual lesions. Therefore there is no indication of systemic treatment.

Even if in our patient one lesion of 2 cm in size and another 14 lesions occurred ranging in size from 0.5 cm to 2 cm, the carcinoide syndrome or liver metastasis were not present. Only positive regional lymph nodes metastases were evaluated in the specimen. There are no data for the adjuvant treatment.

5-year survival rate in patients with NET and the regional lymph node involvement reaches 70–90% after curative surgery with lymphadenectomy [1,4,20].

Conclusion

We present an 80-year-old man with OGIB. In our rare case, a patient with 15 lesions of NET in the ileum was diagnosed by CE and successfully cured by surgical resection of the ileum.

Supported by Ministry of Health, Czech Republic – conceptual development of research organization (FNBr, 65269705).

Petr Kysela, M.D., Ph.D.

kysela.petr@fnbrno.cz

Department of Surgery, University Hospital Brno Bohunice, Faculty of Medicine, Masaryk University

www.fnbrno.czwww.med.muni.cz