We have presented a brief history, physical examination, and roentgenograms of a condition of unusual bone pathology characterized by a peculiar distribution confined to the bony structures of the lower forearm, wrist, hand, and fingers, corresponding with the superficial ulnar nerve distribution plus the entire ulna. The changes in the bones are characterized by increased production of bone, sclerosis, eburnation, almost complete disappearance of medulla, with obliteration of cortical outlines, slight periosteal thickening, lack of atrophy, or canalization, and no invasion of the soft tissues. The ulna is outwardly curved and there is decreased deep sensibility to tuning-fork tests applied to the bones involved. The etiology may lie in a congenital anomaly or a neurologic or vascular disturbance.

Dr. C. Judson Herrick says that if there is a nervous factor in this case it does not correspond with peripheral distribution nor spinal cord segmentation, but with spinal root or spinal ganglion segmentation, in which case it might be of spinal ganglion origin or of sympathetic eflerent connection, by way of the eighth cervical or first thoracic roots.

Remarks: The writers are unfortunately unable to furnish any other data in regard to history, serological tests, blood chemistry, microscopical or bacteriological examinations, because the patient does not know the first and will not permit the others. They would appreciate any assistance in classifying this condition.