16 February 2026
: Case report 
Insulin Autoimmune Syndrome Associated With Hashimoto Thyroiditis and Nodular Thyroid Disease: Clinical Management With Flash Glucose Monitoring and Prednisolone Therapy
Rare disease
Andrzej Nowak
ABDEF 1, Karolina Morawiec-Sławek ABDE 2, Marcin Motyka BCD 1, Małgorzata Trofimiuk-Müldner ACDEF 2*, Alicja Hubalewska-Dydejczyk ADF 2
DOI: 10.12659/AJCR.951425
Am J Case Rep 2026; 27:e951425
Table 1 Comparative characteristics of insulin autoimmune syndrome, insulinoma, advanced dumping syndrome, and factitious hypoglycemia.
| Feature | Insulin autoimmune syndrome | Insulinoma | Advanced dumping syndrome | Factitious hypoglycemia (eg, Munchhausen syndrome caused by insulin use) |
|---|---|---|---|---|
| Etiology | Autoimmune reaction with high insulin autoantibodies, no exogenous insulin | Pancreatic beta-cell neuroendocrine tumor | Post-gastric surgery complication | Surreptitious insulin administration |
| Typical patient’s history | No insulin therapy; often linked to drug exposure (eg, methimazole, alpha-lipoic acid) | No exogenous insulin use; symptoms for months/years | History of gastric surgery | Psychiatric history; healthcare background |
| Timing of hypoglycemia | Postprandial and nocturnal | Fasting hypoglycemia | Postprandial | Random |
| Insulin concentrations | Very high | High | Moderately elevated | High |
| C-peptide concentrations | Normal or high | High | Normal | Low |
| Insulin autoantibodies | Positive | Negative | Negative | Negative |
| Imaging findings | Negative | Often positive on imaging (MRI/CT/EUS/functional imaging) | Negative | Negative |
| Treatment | Often remits spontaneously; responds to steroids | Surgical removal as first-line treatment | Dietary modification effective | Psychiatric intervention needed |