[Recurrent hypoglycemia and a large intraabdominal tumor in a 61-year-old woman].

HISTORY AND ADMISSION FINDINGS: A 61-year-old woman was found unconscious by her husband. The emergency doctor detected hypoglycemia (blood glucose 1.7 mmol/l). This was the first such event, the patient had not been known to have diabetes mellitus. At admission the physical examination and the laboratory findings revealed no abnormalities.

INVESTIGATIONS: A fasting test was aborted shortly after the start because of the onset of neurological symptoms. An insulinoma was excluded by detecting suppressed levels of insulin and C-peptide. Computed tomography of the abdomen revealed a mesenteric tumour of 9 cm in diameter, which was identified immunhistologically as a grade 1 follicular lymphoma (FL).  After exclusion of endocrinological causes the recurrent hypoglycaemia was diagnozed as part of a paraneoplastic syndrome associated with a non-islet cell tumour hypoglycaemia (NICTH) with a newly diagnosed FL.

TREATMENT AND COURSE: Specific medication with the CD20 antibody rituximab (375 mg/m2, once per week for a total of four cycles) was initiated. There were no further episodes of hypoglycaemia. After one year the patient remains free of any symptoms.

CONCLUSIONS: After exclusion of any endocrinological reasons for hypoglycemia, differential diagnosis should include NICTH as paraneoplastic syndrome. In rare cases a hematological malignancy may be the underlying disease. The specific treatment of this disease likewise represents the causal treatment of NICTH.