Fatal Diabetic Ketoacidosis Probably Precipitated by Suspected Sepsis from a Recurrent Lateral Cervical Cystic Lesion: An Autopsy Case Report

Diabetic ketoacidosis (DKA) is a life-threatening complication of diabetes mellitus (DM) that may be precipitated by infection. We report the forensic autopsy of a 32-year-old woman with previously undiagnosed and reportedly untreated DM who was found dead at home after approximately 10 days of decreased appetite and 7 days of inability to eat solid food, without seeking medical care. She had a history of recurrent lateral neck swelling and discharge since early adulthood. At autopsy, a subcutaneous cystic lesion with a cutaneous draining opening was present in the left lateral neck. Histopathologically, the lesion showed extensive suppurative inflammation, keratinous debris without an identifiable epithelial lining, and adjacent lymphoid tissue; the kidneys showed pyelonephritis with microabscesses. Postmortem biochemistry showed hemoglobin A1c 15.7%, cardiac blood glucose 1308 mg/dL, femoral serum beta-hydroxybutyrate 7440 μmol/L (7.44 mmol/L), and femoral serum acetone 0.543 mg/mL; ethanol and other drugs were not detected. Methicillin-susceptible Staphylococcus aureus (MSSA) was isolated from cardiac blood, cerebrospinal fluid, and the lesion contents. DKA was considered the cause of death. Systemic MSSA infection originating from the cervical lesion, with suspected but unproven sepsis, was considered the most likely precipitating factor, with possible contributions from pyelonephritis, reduced oral intake, and dehydration. The lesion was most likely an infected branchial cleft anomaly, although an infected epidermoid cyst could not be excluded. This case shows how investigative information and postmortem examinations can be integrated to reconstruct the most likely sequence leading to death while distinguishing demonstrated findings from inferred causal relationships.