Carcinomatous encephalomyelitis with auditory and vestibular manifestations

A clinical and pathological study of carcinomatous encephalomyelitis is presented. Attention is drawn to the various types of nonmetastatic paraneoplastic syndromes and their particular association with oat cell carcinoma of the lung. The feature of special interest in this study is the onset with otologic symptoms, sudden deafness in the left ear and vertigo, at a time when the neoplastic basis for the disease was not clinically evident. The most striking change in the left temporal bone is the almost total loss of cochlear neurons in Rosenthal's canal and degeneration of both divisions of the vestibular nerve. The organ of Corti and stria vascularis are normal throughout the cochlear duct. The vestibular sense organs are normal. The left cochlear nucleus is devoid of neurons, this neuronal loss is accompanied by a well developed astrocytic and microglial response similar to that in the medulla and spinal cord. This represents a carcinomatous sensory neuropathy involving the left VIII nerve with simultaneous involvement of the left cochlear nucleus. The pathogenesis of this condition still defies explanation, but there are some insights in the autoimmune sector.