Peripheral neuropathy associated with osteosarcoma in a Japanese monkey

Peripheral neuropathy associated with osteosarcoma of the humerus was reported in a Japanese monkey (Macaca fuscata). The monkey developed osteosarcoma in the right humerus. Postmortem morphometric analyses on lower limb nerves revealed loss and size reduction of myelinated nerve fibers. Pathological findings including various demyelinative processes were found with electron microscopy. These findings were more predominant in the distal part than in the proximal part of the nerves, which is compatible with axonal degeneration of peripheral nerve fibers. This is the first case found in a monkey of dying-back neuropathy associated with malignancy, which is not infrequent in humans.