hypercalcemia , syndrome of inappropriate secretion of antidiuretic hormone , cushing 's syndrome , and skeletal - connective tissue syndromes are common in patients with lung cancer , especially those with small cell lung cancer ( sclc ) .
approximately two thirds of sclc patients present with metastatic stage at the time of diagnosis .
lambert - eaton syndrome occurs in 3%percnt ; of sclc patients as neurological paraneoplastic syndrome .
however , the association of malignancy and guillain - barr syndrome ( gbs ) is not well known .
it is a rare disease that occurs at a rate of 1.11 cases per 100,000 person - years .
however , once infected , up to 20%percnt ; of patients develop severe disability , and approximately 5%percnt ; die .
there have been reports of paraneoplastic gbs in different cancers . to the best of the present authors knowledge ,
there are 6 published reports of gbs in sclc [ 2 , 3 , 4 , 5 , 6 , 7 ] . here
, we report a case of a 52-year - old man who was diagnosed with gbs in sclc with chemotherapy .
he was diagnosed with sclc , limited disease , at another hospital 5 years ago .
he had been recommended concurrent chemoradiotherapy at that time but had wanted to be treated with chemotherapy only .
after 6 cycles , complete remission was noted , and prophylactic cranial irradiation was given .
a year later , he had relocated residence and visited our hospital , presenting with relapsed lung cancer but refusing treatment . after 7 months , further disease progression and pancreatic metastasis was noted on computed tomography ( ct ) scanning .
meanwhile , superior vena cava syndrome occurred , and radiation therapy was delivered in the middle of chemotherapy . a ct scan for the response showed disease progression .
he was started on cisplatin , doxorubicin , and cyclophosphamide ( cap ) and also received palliative brain radiotherapy due to brain metastasis during the chemotherapy .
however , in his fifth year of cancer diagnosis , he presented with lower - limb weakness and was admitted .
he noticed weakness in both legs 2 weeks prior to admission and developed numbness throughout the lower extremities .
a neurological examination revealed no nuchal rigidity or kernig 's sign as well as absence of deep tendon reflexes .
magnetic resonance imaging ( mri ) of the brain showed some unidentified bright objects ( fig .
however , there was little possibility of brain metastasis or embolic infarction when comparing the patient 's symptoms and physical examination with the mri lesions . to evaluate neurologic problems ,
it revealed a fracture of the second lumbar vertebra that seemed to be benign ( fig .
, the ascending paralysis , from the lower extremities to the upper extremities , did not correlate with the cord compression lesion either .
nerve conduction studies showed decreased amplitudes and slow velocities of compound muscle action potential and sensory nerve action potential in the extremities .
a lumbar puncture yielded cerebrospinal fluid protein 94 mg / dl , albumin 61.3 mg / dl , glucose 173 mg / dl , and white blood cells 1/l .
these were assessed as being due to albuminocytological dissociation , and there were no signs of meningitis .
the patient was diagnosed with gbs and was recommended treatment with intravenous immunoglobulin ( ivig ) , which he refused .
it could be caused by adverse effects of chemotherapy or by other underlying diseases that have nothing to do with malignancies , such as diabetes .
however , these sensorimotor neuropathies almost always result in mild to moderate dysfunction and usually do not affect patients survival .
it is characterized by both limbs and muscles innervated by cranial nerves being weakened . approximately 70%percnt ; of gbs cases
a progressive bilateral , symmetric weakness of the extremities manifests over a period of 12 h to 28 days from disease onset .
the nerve conduction study result was consistent with acute peripheral neuropathy , a cerebrospinal fluid analysis demonstrating an elevated protein level and absence of leukocytosis due to albuminocytological dissociation will be helpful to confirm the gbs diagnosis .
gbs should take into account various diseases , such as brain or leptomeningeal metastasis from cancer , and spinal cord compression .
described neuropathy occurring after treatment with a combination of oxaliplatin and cisplatin ; nardone et al .  
in addition , when patients with gbs are not able to walk independently , immunotherapy is required . in immunotherapy , either ivig or plasmapheresis can be used .
these treatments have been observed to be effective when started within the first 2 weeks after disease onset .
gbs occurred in a patient receiving long - term antineoplastic therapy , whereas gbs had occurred at the initial point of presentation in the 6 other cases [ 2 , 3 , 4 , 5 , 6 , 7 ] .
this is the first reported case of paraneoplastic gbs that developed in an sclc patient with long - term therapy . to the present authors knowledge ,
in the 5 cases of gbs with sclc , there was no relationship between chemotherapy and gbs . in 4 of the 5 reports ,
patients received chemotherapy ; however , in all 4 of these reports , the patients underwent chemotherapy after gbs had been diagnosed and ivig had been given .
in addition , in 3 of these 4 reports , a combination of etoposide and carboplatin was used , whereas the other report did not indicate the chemotherapy regimen [ 2 , 3 , 4 , 5 , 6 ] .
immunotherapy was recommended at the time of diagnosis , but he refused the treatment because of his advanced cancer stage and poor general condition .
patients with cancer are vulnerable to infection and can have problems with the immune system . as illustrated by this report , paraneoplastic gbs in sclc is a life - threatening disease .
thus , it should be monitored and treated when acute progressive peripheral neuropathy occurs in patients with sclc .
the authors submitted a waiver from their institutional review board stating that this case report does not require institutional review board approval or oversight .
 guillain - barr syndrome ( gbs ) is defined as an acute , autoimmune polyradiculoneuropathy . 
 it is a rare disease that occurs at a rate of 1.11 cases per 100,000 person - years . 
 however , once infected , up to 20%percnt ; of patients develop severe disability , and approximately 5%percnt ; die . 
 there have been reports of gbs in different cancers . among them 
 , there are 6 previous reports of gbs in small cell lung cancer . here 
 , we report a case of a 52-year - old man who was diagnosed with gbs in the setting of small cell lung cancer with chemotherapy . 
Introduction
Case Report
Discussion
Disclosure Statement
Statement of Ethics