Retrobulbar neuritis as the first sign of the glucagonoma syndrome

Pancreatic neuroendocrine paraneoplastic optic neuropathy: confirmation with antibody to optic nerve and hepatic metastasis

A 68-year-old woman presented with bilateral visual loss as the only clinical manifestation of an occult pancreatic nonsecretory neuroendocrine tumor (NET). The suspected diagnosis of paraneoplastic optic neuropathy was confirmed using immunofluorescence assays to demonstrate the presence of antibodies in the patient's serum that reacted with antigen(s) in the optic nerve and in the pancreatic NET hepatic metastasis. Treatment of the underlying cancer was followed by marked improvement in visual function.

A Rare Cystic Non-Functioning Neuroendocrine Pancreatic Tumor with An Unusual Presentation

This report describes a patient with a cystic non-functioning neuroendocrine glucagon cell pancreatic tumor presenting with demyelination of the optical nerve that had initially provoked marked monolateral reduced vision and had led to a suspected diagnosis of multiple sclerosis. Cystic degeneration is uncommon in endocrine pancreatic tumors due to their abundant vascular supply. Very few cases of cystic neuroendocrine non-functioning pancreatic tumors have been reported in the international literature. The presence of atypical neurological symptoms, such as sudden visual impairment, should be taken into account in the differential diagnosis for such tumors. The prognosis is poor, because most of these tumors are malignant and diagnosed at an advanced stage. The three-year disease-free survival of our patient, however, encourages the use of aggressive surgical treatment.

Paraneoplastic retinopathies and optic neuropathies

Unusual neuro-ophthalmologic symptoms and signs that go unexplained should warrant a thorough investigation for paraneoplastic syndromes. Although these syndromes are rare, these clinical manifestations can herald an unsuspected, underlying malignancy that could be treated early and aggressively. This point underscores the importance of distinguishing and understanding the various, sometimes subtle, presentations of ocular paraneoplastic syndromes. Outlined in this review article are diagnostic features useful in differentiating cancer-associated retinopathy, melanoma-associated retinopathy, and paraneoplastic optic neuropathy. These must also be distinguished from non-cancer-related eye disorders that may clinically resemble cancer-associated retinopathy. The associated antibodies and histopathology of each syndrome are presented to help in the understanding of these autoimmune phenomena. Treatment outcomes from reported cases are summarized, and some potential novel immunotherapies are also discussed.

The glucagonoma syndrome: a review of its features and discussion of new perspectives

Glucagonoma syndrome is a paraneoplastic phenomenon characterized by an islet alpha-cell pancreatic tumor, necrolytic migratory erythema, diabetes mellitus, weight loss, anemia, stomatitis, thromboembolism, and gastrointestinal and neuropsychiatric disturbances. These clinical findings in association with hyperglucagonemia and demonstrable pancreatic tumor establish the diagnosis. Glucagon itself is responsible for most of the observed signs and symptoms, and its induction of hypoaminoacidemia is thought to lead to necrolytic migratory erythema. Liver disease and fatty acid and zinc deficiency states may also contribute to the pathogenesis of the eruption in some cases. Most patients are diagnosed too late in the clinical course for cure, but successful palliation of symptomatology can usually be achieved with surgical and medical intervention. This paper reviews the glucagonoma syndrome, paying particular attention to its cutaneous features, and provides new perspectives in our current understanding of this phenomenon.

A review of the therapy of paraneoplastic neurologic syndromes

The therapy of paraneoplastic neurologic syndromes remains unclear and warrants a systematic review of the literature. Reports in English and foreign language literature were abstracted. Data were sorted by the primary paraneoplastic neurologic syndrome, the primary malignancy, and the methods of treatment. Neurologic improvement follows surgical, chemotherapeutic, and radiation treatments. Adjuvant immunosuppressive therapy with steroids, plasmapheresis, or immunoglobulin may help stabilize the progression of neurologic symptoms. Syndromes characterized by inflammation or neurotransmitter production without neuronal loss are most responsive to therapy. While treatment of the underlying cancer with appropriate surgery, chemotherapy, and radiation is recommended, the paraneoplastic syndrome should probably be managed with immunosuppressive therapy.

Gastrointestinal endocrine tumours. Glucagonomas

Glucagonoma is an uncommon, challenging but treatable disease with varied manifestations. Despite its predominantly malignant nature, prolonged symptom-free survival can be achieved using a targeted combination of surgery, hepatic artery embolization and somatostatin analogues. Given the difficult management issues, an initial assessment in an experienced tertiary referral centre may also be of benefit. This chapter has looked at the long-term follow-up of 18 such patients over a 25-year period. Given the rarity of the tumour, the numbers are small, but valuable lessons can be learnt from the study in the clinical management of these patients.

Reversal of a neurologic paraneoplastic syndrome with octreotide (Sandostatin) in a patient with glucagonoma

A 69-year-old woman with classic glucagonoma syndrome had associated progressive neurologic disease manifest as dementia, ataxia, optic atrophy, and lower limb weakness. Visual evoked responses (VERs) were absent bilaterally. After an attempt at resection was unsuccessful, therapy was started with somatostatin analogue (Sandostatin, SMS 201-995). Over the ensuing 3 months, there was a decrease in the plasma glucagon level, resolution of the rash, weight gain, reversal of the dementia, and an improvement in coordination and limb weakness. Subsequent VERs revealed bilateral delayed responses.