Bilateral tonic pupils with evidence of anti-hu antibodies as a paraneoplastic manifestation of small cell lung cancer.

INTRODUCTION

Ophthalmological manifestations of systemic malignancies can be either direct, metastatic or paraneoplastic. The latter are remote effects of carcinoma, often caused by autoantibodies. Ophthalmological manifestations include cancer-associated retinopathy, melanoma-associated retinopathy, opsoclonus-myoclonus syndrome or motility disorders due to effects on the neurological system. A unilateral tonic pupil is usually a benign finding but has also been described in the context of paraneoplastic syndromes, in some cases associated with anti-Hu antibodies.

CASE REPORTS

The authors describe 2 patients with bilateral symptomatic tonic pupils due to a paraneoplastic syndrome. Both patients had been treated for small cell lung cancer and had evidence of anti-Hu antibodies (autoantibodies against nuclei of neural cells) in serum and cerebrospinal fluid. Both had typical pupillary findings and hypersensitivity to diluted pilocarpine. The first patient also had sensory neuronopathy, the second affection of several cranial nerves.

DISCUSSION

To the best of our knowledge, to date no case of bilateral tonic pupils has been published due to a paraneoplastic disorder with evidence of autoantibodies. This is surprising, as it is probable that autoantibodies in paraneoplastic disorders affect both ciliary ganglions in a similar way.