Differential Diagnosis for a 40-year-old Female with New Onset Type 2 DM, Intermittent Pain, and Obstructive Jaundice

Single Most Likely Diagnosis

• Pancreatic Cancer: This is a leading consideration given the combination of new onset Type 2 diabetes mellitus (DM), intermittent pain, and obstructive jaundice. Pancreatic cancer can cause pain, obstructive jaundice due to bile duct obstruction, and new onset diabetes due to pancreatic islet cell destruction.

Other Likely Diagnoses

• Chronic Pancreatitis: This condition can cause intermittent abdominal pain, obstructive jaundice if there is significant pancreatic duct obstruction, and new onset diabetes due to pancreatic damage. The history of intermittent pain for 2 years supports this diagnosis.
• Choledocholithiasis (Gallstones in the Bile Duct): While more commonly associated with acute presentations, chronic or recurrent obstruction can lead to intermittent jaundice and pain. New onset diabetes is not directly related but can coexist.
• Ampullary or Periampullary Cancer: These tumors can cause obstructive jaundice and, less commonly, new onset diabetes. Pain may be a feature, especially if the tumor obstructs the pancreatic duct.

Do Not Miss Diagnoses

• Metastatic Cancer to the Pancreas or Bile Ducts: Although less common, metastases to the pancreas or bile ducts from other primary sites (e.g., breast, lung, colon) can mimic primary pancreatic or bile duct cancers and must be considered to avoid missing a potentially treatable condition.
• Primary Sclerosing Cholangitis (PSC): A chronic liver disease characterized by inflammation and scarring of the bile ducts inside and outside the liver. It can cause obstructive jaundice and, occasionally, abdominal pain. New onset diabetes is not a direct consequence but can coexist.

Rare Diagnoses

• Intraductal Papillary Mucinous Neoplasm (IPMN): A rare tumor that grows within the pancreatic ducts and can cause obstructive jaundice and pancreatitis. New onset diabetes can occur if there is significant pancreatic involvement.
• Autoimmune Pancreatitis: A rare form of pancreatitis characterized by an autoimmune inflammatory process. It can cause obstructive jaundice, abdominal pain, and, less commonly, new onset diabetes.
• Genetic Disorders (e.g., Hereditary Pancreatitis, Cystic Fibrosis): These conditions can lead to chronic pancreatitis and, consequently, new onset diabetes and obstructive jaundice, although they are more typically identified at a younger age.

Each of these diagnoses should be considered in the context of the patient's full clinical presentation, including any additional symptoms, physical examination findings, laboratory results, and imaging studies.