Sandbox: DDx 2

DDX 1

Differential Diagnosis	Key Symptoms	Characteristic Lab Findings	CT Scan	Characteristic Histopathological Features
Insulinoma	Diaphoresis Tremor Palpitations Seizures Coma	Hypoglycemia Hyperinsulinemia Elevated C-peptide level Elevated Pro-insulin level	Calcification and hyperattenuation of the mass	Solid or gyriform cellular patterns Amyloid deposition Nesidioblastosis may be present Absence of glands
VIPoma	Watery diarrhea Dehydration Lethargy Muscle weakness Flushing	Elevated (VIP) levels Elevated neurotensin levels Hypokalemia Hypomagnesaemia Hypercalcaemia Metabolic acidosis	Hypervascularity with diffuse multiple metastatic nodulation	Solid sheets Uniform cuboidal cells Centrally located nuclei Stippled chromatin Granular eosinophilic cytoplasm
Gastrinoma	Epigastric abdominal pain Diarrhea Heartburn Hematemesis	Elevated serum gastrin level Positive secretin stimulation test	Small hypoattenuating nodule ± calcification	Lobular-trabecular pattern Gastrin+ tumor cells Infiltration of Brunner glands

DDX 2

Characteristics	Insulinoma	Vipoma	Gastrinoma
Symptoms
Diaphoresis	Present	Absent	Absent
Watery diarrhea	Absent	Present	Absent
Heartburn	Absent	Absent	Present
Lab values
Hypoglycemia	Present	Absent	Absent
Hypokalemia	Absent	Present	Absent
Hypergastrinemia	Absent	Absent	Present
Imaging
CT Scan	Calcification and hyperattenuation of the mass	Hypervascularity with diffuse multiple metastatic nodulation	Small hypoattenuating nodule ± calcification
MRI	T2-weighted, increased-signal intensity mass	T1-weighted, decreased-signal-intensity masses	T1-weighted, decreased-signal intensity masses
Histopathology	Solid or gyriform cellular patterns with amyloid deposition, absence of glands, and nesidioblastosis	Solid sheets with uniform cuboidal cells, centrally located nuclei, and granular cytoplasm	Lobular-trabecular pattern of gastrin positive tumor cells with infiltration of Brunner glands