INTERNATIONAL JOURNAL OF CLINICAL AND MEDICAL CASES (ISSN:2517-7346)

Small intestinal neuroendocrine tumors are the most common type of neuroendocrine tumors and small bowel neoplasms. The clinical presentation varies from asymptomatic incidentally detected localized lesions to lethal metastatic disease with carcinoid syndrome.

A 50 year old lady presented with chief complaints of lump in upper abdomen associated with dull aching pain for 3 months. Cect scan was suggestive of a probable gastrointestinal stromal tumour for which patient underwent elective laparotomy. Postoperatively on the basis of histopathology a diagnosis of neuroendocrine tumor was made and confirmed by immunohistochemistry. Approximately 90% of duodenal NET’s are not associated with a clinical syndrome. It is a rare diagnosis with incidence of 0.5/100,000.

Patients with well differentiated tumours diagnosed in early stage have a good prognosis with an 85% overall 5year survival rate.

Neuroendocrine; Gastrointestinal ; Stromal; Duodenum 

Neuroendocrine tumors are a heterogeneous group of neoplasms arising from various anatomical sites with the majority originating from small intestine and pancreas.

They originate in the enterochromaffin cells of the aerodigestive tract.

The underlying pathogenic mechanisms have been poorly characterized due to relative rarity [1].

Small intestinal neuroendocrine tumors are the most common type of neuroendocrine tumors and small bowel neoplasms. The clinical presentation varies from asymptomatic incidentally detected localized lesions to lethal metastatic disease with carcinoid syndrome [2].

Functional neuroendocrine tumors are characterized by a clinical syndrome caused by excess hormonal secretion while non-functional neuroendocrine tumors are hormonally silent [3].

Intestinal neuroendocrine tumors have distinct features depending on their site of origin.

Neuroendocrine tumors originating in the duodenum are not well characterized. Many are discovered incidentally during endoscopy [4]. Unlike other midgut neuroendocrine tumors, they are not commonly associated with the typical carcinoid syndrome.

NET’s usually have an indolent clinical course, but tumor behavior varies widelydepending on 2017 WHO (World Health Organization) grading, based on Ki-67 proliferation index and mitotic count [5]. 

A 50 year old lady presented with chief complaints of lump in upper abdomen associated with dull aching pain since 3 months.

There were no associated complaints of pain, fever, vomiting, constipation, diarrhoea, passage of blood in urine or stools, breathlessness, loss of weight or appetite and no complaint of other swellings on the body. The Patient was not a known case of diabetes mellitus, hypertension, heart disease, asthma or any other major illnesses.

The Patient is not a known alcoholic, smoker or drug addict. There is history of attaining menopause 5 years ago. Presently the patient bears two children.

On physical examination, the patient was vitally stable. Per abdomen examination was soft to touch, non-tender with no guarding or rigidity felt. A lump of 15x8cm was felt in left hypochondriac and epigastric region, firm in consistency, immobile, non-tender with no local rise in temperature and with a smooth overlying surface. Per vaginal and per rectal examination had no abnormal findings.

Routine lab investigations were within normal limits

The Patient was referred with a contrast enhanced computed tomography scan of the abdomen and pelvis which was suggestive of

1. A large, well-defined solid heterogenously enhancing exophytic mass lesion of size 12x8cm containing non enhancing necrotic areas, arising from the third part of duodenum.

2. Two well defined nodular enhancing lesions of approximate size 2x1 cm and 3x1cm from the second part of duodenum.

Following above findings, CT was suggestive of a probable gastrointestinal stromal tumour with paraduodenal nodes (Figure 1,2).

An upper gastrointestinal endoscopy was performed which was within normal limits. USG guided biopsy or FNAC was not done due to the high vascularity of tumour.

Following investigations and anesthesia fitness, the patient was posted for an elective exploratory laparotomy.

1. There was evidence of a large 15x8x6cm exophytic growth from third and fourth part of duodenum, duodenojejunal flexure and proximal jejunal segment.

2. Another 4x2cm and 3x2cm growths were seen rising from the second part of duodenum.

Intraoperative decision was taken to perform Whipple’s procedure.

Resection of the large tumor with associated jejunal segment was done with primary closure of proximal and distal duodenum.

Cholecystectomy was done with resection of pylorus, duodenum and part of pancreas followed by sequential pancreaticojejunostomy, choledochojejunostomy, gastrojejunostomy and feeding jejunostomy (Figure 3 and 4).

Postoperatively the patient was managed aggressively and closely monitored. Multiple blood transfusions and parenteral nutrition were supplied consecutively. Feeding jejunostomy feeds were started on the fifth day postoperatively. Abdominal drain in subhepatic space was removed on the sixth day while the pelvic drain was removed on the tenth day postoperatively.

Histopathology report was as follows 

1. Grade 1 neuroendocrine tumour of duodenum with low mitotic activity and lack of necrosis.
2. Multiple neuroendocrine tumours of mesentery
3. Resected ends of duodenum and jejunum were free of tumour
4. Gall bladder, pancreas and pylorus were free of tumour 

The Further histopathology block was sent for Immunohistochemistry and KI 67 to enable exact grading that showed mitotic index less than 1, that was suggestive of a low grade, well differentiated tumour, following which patient was discharged on feeding jejunostomy and oral feeds and followed up after two and four weeks respectively (Figure 5-7).