Paramedullary plasmacytoma originating from the first cervical vertebra (C1) in an 8-month-old warmblood weanling with tetraparesis: Clinical and pathological findings

Abstract

To the authorsʼ knowledge there is only one report in the literature, dealing with paramedullary plasmacytomas in horses as so-called “break out lesions”, originating from the bone marrow of a vertebra and invading the epidural space (Drew and Greatorex 1974). Our case report describes the clinical and patho-morphological findings of such a case. The affected 8-month-old warmblood weanling colt exhibited acute tetraparesis thus, a spinal cord lesion in the cervical column was suspected. Computed tomography revealed osteolytic lesions in C1 and a heterogeneous mass within the respective segment of the vertebral canal. By means of patho-morphological examination, with the aid of transmission electron microscopy, a plasmacytoma was identified, that had grown out of the bone marrow of C1 into the epidural space, locally compressing the spinal cord. In tetraparetic, young horses traumatic spine cord injuries, cervical vertebral malformations and infectious diseases of the central nervous system represent common differentials. However bone-dissolving tumours such as paramedullary plasmacytomas should be considered as a further possible cause in the presence of severe neurological deficits.