Colorectal carcinoma and chronic inflammatory demyelinating polyneuropathy: is there a possible paraneoplastic association?

A plethora of paraneoplastic syndromes have been reported as remote effects of colorectal carcinoma (CRC). However, there is a dearth of data pertaining to the association of this cancer with demyelinating neuropathies. Herein, we describe the case of a young woman diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP). Treatment with intravenous immunoglobulins and prednisone did not improve her condition, and her neurological symptoms worsened. Subsequently, she was readmitted with exertional dyspnea, lightheadedness, malaise, and black stools. Colonoscopy revealed a necrotic mass in the ascending colon, which directly invaded the second part of the duodenum. Pathologic results confirmed the diagnosis of locally advanced CRC. Upon surgical resection of the cancer, her CIDP showed dramatic resolution without any additional therapy. Patients with CRC may develop CIDP as a type of paraneoplastic syndrome. Clinicians should remain cognizant of this potential association, as it is of paramount importance for the necessary holistic clinical management.