A glucagon-secreting pancreatic alpha islet cell tumor presenting as spinal cord compression

We describe a patient with a pancreatic islet carcinoma presenting with spinal cord compression owing to vertebral metastases. Subsequent studies demonstrated a typical islet cell carcinoma by light microscopy. By electron microscopy, the neurosecretory granules were morphologically suggestive of glucagon production. Radioimmunoassay studies revealed markedly elevated levels of serum glucagon. Notably, the patient did not exhibit the characteristic glucagonoma syndrome. This case exemplifies clearly that elevated levels of immunoreactive neuropeptide hormones are not necessarily associated with overt hormonal syndromes. Possible mechanisms for explaining this apparent discrepancy include the production of immunoreactive molecules with weak or absent systemic biological activity. Nevertheless, the determination of immunoreactive hormone levels in neuroendocrine neoplasms is an extremely effective adjunct method for their diagnosis and monitoring.