J Med Cases

Journal of Medical Cases, ISSN 1923-4155 print, 1923-4163 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Med Cases and Elmer Press Inc

Journal website https://www.journalmc.org

Case Report

Volume 12, Number 5, May 2021, pages 195-201

Pancreatic VIPoma as a Differential Diagnosis in Chronic Pediatric Diarrhea: A Case Report and Review of the Literature

Figure 3. (a) Octreotide scintigraphy showing hyperintense lesion pancreas. (b) Magnetic simple and proven abdomen showing focal lesions solid appearance adjacent to the posterior and superior aspect of the pancreas body (arrow).

**Table 1.** VIPoma Classification
2017 WHO panNEN Tumor Classification	Ki proliferation index (%)*	Mitotic index^†
*The Ki-67 proliferation index is based on the evaluation of ≥ 500 cell in areas of higher nuclear labeling (hot spot). ^†The mitotic index is based on the evaluation of mitoses in 50 high-power fields in areas of higher density, and is expressed as mitoses per 10 high-power fields (2.0 mm²). G1: grade 1; G2: grade 2; G3: grade 3; PanNEN: pancreatic neuroendocrine neoplasm; PanNEC: pancreatic neuroendocrine carcinoma; PanNET: pancreatic neuroendocrine tumor.
Well-differentiated panNET
G1	< 3	< 2
G2	3 - 20	2 - 20
G3	> 20	> 20
Poorly-differentiated panNEC
PanNEC G3	> 20	> 20
Small cell type
Large cell type
Mixed neuroendocrine-non-neuroendocrine neoplasm

Table 1. VIPoma Classification

2017 WHO panNEN Tumor Classification

Ki proliferation index (%)*

Mitotic index^†

*The Ki-67 proliferation index is based on the evaluation of ≥ 500 cell in areas of higher nuclear labeling (hot spot). ^†The mitotic index is based on the evaluation of mitoses in 50 high-power fields in areas of higher density, and is expressed as mitoses per 10 high-power fields (2.0 mm²). G1: grade 1; G2: grade 2; G3: grade 3; PanNEN: pancreatic neuroendocrine neoplasm; PanNEC: pancreatic neuroendocrine carcinoma; PanNET: pancreatic neuroendocrine tumor.

Well-differentiated panNET

< 3

< 2

3 - 20

2 - 20

> 20

Poorly-differentiated panNEC

PanNEC G3

> 20

Small cell type

Large cell type

Mixed neuroendocrine-non-neuroendocrine neoplasm

**Table 2.** VIPoma Clinical Characteristics in Pediatric Patients Across Published Case Reports
VIP: vasoactive intestinal peptide; MRI: magnetic resonance imaging; CT: computed tomography.
Age (years old)/gender (M/F)	7 months/M	11/F	12/M	15/F	2/F
Symptom	Diarrhea, dehydration	Secretory diarrhea	Dehydration, diarrhea, dizziness and flushing	Diarrhea, vomiting, fatigue and thirst	Diarrhea, failure to thrive, weight loss
Fecal spending	-	2 L/day	-	8 - 10 L/day	-
Serum potassium	3.3 mEq/L	2.9 mEq/L	-	1.7 mEq/L	< 2 mEq/L
VIP serum	166 pg/mL	-	134.5 pg/mL	2,150 pg/mL	2,030 pmol/L
Other markers	-	-	Gastrin (138 pg/mL)	Normal	-
Diagnostic method	Exploratory laparotomy	Abdominal MRI	Abdominal MRI	Endoscopic retrograde cholangiopancreatography	Triple-phase CT scan
Tumor location in pancreas	Tail	Body - tail	Tail	Body - tail	-
Tumor size	5.0 × 5.0 × 5.0 mm	4 × 5 cm	1.5 × 1.0 × 0.8 cm	6 × 5 cm	-
Metastasis	-	Yes	Yes	Yes	-
Metastasis location	-	Peripancreatic lymph nodes	Mesenteric lymph nodes, liver	Spleen, lymph nodes	-
Management	Pancreatectomy	Pancreatectomy + splenectomy	Distal pancreatectomy	Distal pancreatectomy (85%) + splenectomy	Exploratory laparotomy for tumor resection

Table 2. VIPoma Clinical Characteristics in Pediatric Patients Across Published Case Reports

VIP: vasoactive intestinal peptide; MRI: magnetic resonance imaging; CT: computed tomography.

Age (years old)/gender (M/F)

7 months/M

11/F

12/M

15/F

2/F

Symptom

Diarrhea, dehydration

Secretory diarrhea

Dehydration, diarrhea, dizziness and flushing

Diarrhea, vomiting, fatigue and thirst

Diarrhea, failure to thrive, weight loss

Fecal spending

2 L/day

8 - 10 L/day

Serum potassium

3.3 mEq/L

2.9 mEq/L

1.7 mEq/L

< 2 mEq/L

VIP serum

166 pg/mL

134.5 pg/mL

2,150 pg/mL

2,030 pmol/L

Other markers

Gastrin (138 pg/mL)

Normal

Diagnostic method

Exploratory laparotomy

Abdominal MRI

Endoscopic retrograde cholangiopancreatography

Triple-phase CT scan

Tumor location in pancreas

Tail

Body - tail

Tail

Body - tail

Tumor size

5.0 × 5.0 × 5.0 mm

4 × 5 cm

1.5 × 1.0 × 0.8 cm

6 × 5 cm

Metastasis

Yes

Metastasis location

Peripancreatic lymph nodes

Mesenteric lymph nodes, liver

Spleen, lymph nodes

Management

Pancreatectomy

Pancreatectomy + splenectomy

Distal pancreatectomy

Distal pancreatectomy (85%) + splenectomy

Exploratory laparotomy for tumor resection