History: A 60 year old negro male noted progressive numbness of his hands and feet for 3 years. Within the past year his legs became progressively weak and stiff, until he was unable to walk without assistance. The patient denied incontinence. Atrophy of the muscles of the hands and shoulder girdles was noted on admission, and fasciculations were present in the deltoid, biceps and triceps muscles. At this time reflexes were exaggerated in the extremities with Hoffman's and Babinski's signs present bilaterally. Spasticity was marked in the legs and less severe in the upper limbs. The patient's mental status precluded accurate sensory examination, but definite impairment of pain and temperature perception was present in C4 and C5 dermatomes, more marked on the left. Spinal fluid pressure was within normal range and total protein was not increased. Myelographic studies indicated a partial obstruction between C3 and C5 , although no block could be demonstrated by Queckenstedt test. Laminectomy was performed, but no cause for the obstruction was revealed. There was no improvement after the operation, and for the next 2 years the neurological status was unchanged except for progressive muscular atrophy of the ex tremities and urinary incontinence. Death resulted from cardiac disease. Post Mortem Findings: The cord at the site of the cervical laminectomy was thin and ribbon-like with thickening of the dura over the dorsal aspect. Cross section revealed a small discrete tumor embedded in the central portion of the fourth and fifth cervical seg ments (fig. 1). Under the microscope, this appeared as a multi lobulated structure with distinctive, compact arrangement in sharp contrast to the surrounding degenerated neural tissue. The bulk of the neoplasm lay dorsal to the residual ependymal plate, and extended between the posterior horns nearly to the pial margin, with nodular outgrowths reaching into the anterior horns and the lateral columns. The architecture of the neoplasm was relatively uniform, consisting of slender, interlacing bundles of cells and fibers, cut in several planes and in some areas forming loose whorls. The fascicles were formed of parallel rows of narrow, elongated nuclei with scanty polar cytoplasm, intermingled with long, even collagen and reticulum fibers, coursing in the long axes of the nuclei (figs. 2 and 3). The growth was relatively avascular, and no areas of necrosis or microcystic degeneration were seen. Nuclear palisading was not conspicuous, and no Verocay bodies were observed. A thin band of loose, collagenous fibers, in places continuous with the proliferated ad