We feel justified, from the history and findings here presented, in placing this case under Jüngling's classification of osteitis tuberculosa multiplex cystica.
We have found no report in the literature of this disease occurring in the larger long bones.
Previous authors have based their claim for a tuberculous etiology on few positive findings or even on indirect evidence. We have been able to fully establish positive proof of its tuberculous nature by: (1) microscopic tubercles in the cyst wall and in a regional lymph gland; (2) tubercle bacilli in the cyst content; (3) microscopic tubercles in the tissues of a guinea pig six weeks after inoculation; (4) tubercle bacilli in the inoculated guinea pig's lymph nodes; with (5) a positive von Pirquet test, (6) marked chronicity from the start, and (7) a very possible preexisting pulmonary tuberculosis.