Introduction

Pancreatogenic diabetes mellitus, also known as type 3c diabetes mellitus (T3cDM), is a form of secondary diabetes resulting from diseases affecting the exocrine pancreas, including chronic pancreatitis, pancreatic neoplasia, cystic fibrosis, and pancreatic resection [1,2]. Chronic pancreatitis is among the most common etiologies, with progressive pancreatic inflammation leading to irreversible destruction of both endocrine and exocrine tissue [3-5]. Despite increasing recognition, T3cDM remains underdiagnosed and is frequently misclassified as type 2 diabetes mellitus because of overlapping clinical features [2,6].

The American Diabetes Association (ADA) recommends screening for diabetes within three to six months following an episode of acute pancreatitis and annually thereafter, as well as annual screening for patients with chronic pancreatitis [1]. The pathophysiology of T3cDM differs substantially from that of type 2 diabetes mellitus and is characterized by impaired insulin secretion secondary to pancreatic β-cell loss, often accompanied by exocrine pancreatic insufficiency and nutritional deficiencies [2,6]. In contrast to patients with type 2 diabetes mellitus, those with T3cDM frequently demonstrate low or inappropriately normal C-peptide levels, reflecting reduced endogenous insulin production [2].

Management of pancreatogenic diabetes presents unique clinical challenges. Patients often experience brittle glycemic control and are at increased risk for both hyperglycemia and hypoglycemia because of the concomitant loss of glucagon-producing α-cells [6,7]. Current recommendations emphasize early initiation of insulin therapy in many patients, whereas incretin-based therapies are generally avoided because of concerns regarding pancreatitis risk [1,2].

We present a case of a patient with chronic alcoholic pancreatitis status post partial pancreatectomy who developed severe refractory hyperglycemia consistent with pancreatogenic diabetes mellitus. Beyond illustrating the importance of recognizing T3cDM in patients with structural pancreatic disease, this case highlights the diagnostic and therapeutic challenges posed by medication nonadherence, persistent insulin refusal, and psychosocial instability, emphasizing the need for individualized, multidisciplinary management.