The prevalence of paraneoplastic neurologic syndrome in cancer is 0.01%. Neurological syndromes can be seen in chronic lymphocytic leukemia (CLL) and mostly present as either leukemic infiltration of the central nervous system (CNS) or progressive multifocal leukoencephalopathy. To our knowledge, this is the first reported case of combined sensory-motor neuropathy, myopathy, and dermatitis in a patient with CLL.
Case presentation:
A 61-year-old African American man presented with acute dysphagia, rapidly progressive proximal limb-girdle weakness, and dermatitis. He had a white blood cell (WBC) count of 14,600/mm(3), hemoglobin of 11.4 mg/dL, and a platelet count of 165,000/mm(3). Lymphocytes comprised 15% of the total WBC with an absolute lymphocyte count of 2100/mm(3). Metabolic profile was unremarkable except for a serum creatine phosphokinase (CPK) level of 1056 mg/dL. Serum protein electrophoresis, serologic studies for autoimmune, genetic diseases, and paraneoplastic syndromes were all negative. Electrodiagnostic studies revealed sensorimotor neuropathy with mixed axonal and demyelinating features. Muscle biopsy revealed discrete areas of interstitial fibrosis juxtaposed to areas of intact muscle without any inflammation. At that point, a bone marrow biopsy was done because of anemia and slightly elevated mean corpuscular volume of 103. Bone marrow biopsy revealed minimal involvement with CD5/CD19-positive CLL. Flow cytometry demonstrated monoclonal CD5/CD19/CD20/CD23-positive cells, with dim kappa expression, and negative FMC-7 and CD3. This case doesn't meet the criteria for CLL/small lymphocytic lymphoma. However, considering the possibility of paraneoplastic phenomenon for his symptoms, it was decided to start the patient on CLL-directed therapy with Rituximab and Cyclophosphamide. After only two cycles, the patient experienced a dramatic improvement in his muscle strength with disappearance of the rash.
Conclusion:
This case highlights a unique clinical picture of inflammatory dermatitis with electromyography and biopsy findings suggestive of myopathy and combined sensorimotor neuropathy with response to CLL-directed therapy. Also the symptoms started before peripheral lymphocytosis which masked the diagnosis for over a year.