Lessons to be learned: a case study approach--acute appendicitis masquerading as macroamylasaemia.

Macroamylasaemia is a condition in which serum amylase is elevated in the presence of a low to normal urinary amylase and normal renal function. It is rare but can masquerade as other clinical disorders. Discussed here is a case report of a patient who presented initially with abdominal pain (later recognized as being due to gangrenous appendicitis) and in whom there was a very high serum amylase level, leading to an erroneous initial diagnosis and management as acute pancreatitis. The CT scan of the abdomen was normal without any evidence of pancreatitis. Subsequently, the renal amylase:creatinine clearance ratio (C(am)/C(cr)) was found to be low, being characteristic and diagnostic of macroamylasaemia; the latter was, in turn, the cause for the elevated serum amylase level. The underlying macroamylasaemia had thus masqueraded as pancreatitis. The patient underwent appendicectomy and hence made an excellent recovery. It is vitally important to recognize this condition in order to avoid both an incorrect diagnosis and inappropriate treatment/management.