Bing Neel syndrome presenting as isolated cranial nerve palsies – a case report

Background and aims

Waldenstroms macroglobulinemia (WM) is a low-grade B cell neoplasm. Bing Neel syndrome is a rare manifestation of WM characterized by infiltrative involvement of the central nervous system.

Case report

64-year-old man, presented with 4 years history of slowly progressive diplopia and ptosis of eyes. Examination showed left oculomotor (internal and external ophthalmoplegia), with trochlear, abducens, and right partial oculomotor and abducens nerve involvement. Evaluation showed anemia of hemoglobin 10.7 g/dL, raised erythrocyte sedimentation rate of 120 mm/h and plasma albumin:globulin reversal. Serum protein electrophoresis showed a paraprotein peak in the early gamma region with elevated IgM level (3810 mg/dL) and elevated free kappa light chain level (70.1 mg/L). Bone marrow aspiration from posterior iliac crest revealed mature small lymphocytes with positive immunohistochemical markers of CD5, CD10 negativity and MYD88 mutation positivity suggestive of WM. Patient was treated with bendamustine and rituximab regimen, with no neurological improvement at the end of one year.

Conclusion

This case expands spectrum of paraproteinemic neuropathy to include cranial nerve palsy. Thus, plasma cell dyscrasias have to be considered in patients with isolated ophthalmoparesis especially in elderly patients, even with other comorbidities such as diabetes mellitus.