Isolation of Treponema Pallidum from a Subcutaneous Sarcoid

Abstract

Various hypotheses have been advanced in regard to the etiology of the several types of cutaneous and subcutaneous tumors passing under the name of sarcoids.^{1, 2, 3, 4} Upon the basis of histologic structure it seems most likely that the cutaneous type as described by Boeck, 5 and the subcutaneous type of Darier and Roussy 6 belong to the general group of infectious granulomas. Although the common assumption favors their tuberculous origin, it has been only rarely that acid-fast bacilli have been demonstrated directly in stained tissue sections,^{7, 8} and animal inoculations, as a rule, have yielded only negative results.^{9, 10} Recently, however, acid-fast bacilli have been found in the tracheo-bronchial lymph nodes of guinea pigs, inoculated with tissue from sarcoid, in which no gross lesions of the viscera of the animals were detected. 11

Sarcoids are also known to occur infrequently in patients with frank syphilitic infection. In such cases the histologic appearance of the tumors is like that usually considered typical of sarcoid. No reference to the isolation of any bacterial organism from any of the syphilitic cases has been found although Stillians 12 searched for acid-fast bacilli and Treponema pallidum in stained tissue preparations from the patient he observed. The fact that sarcoids in patients with syphilis respond promptly and disappear under anti-syphilitic therapy has little, if any weight as an argument for their syphilitic nature. Similar lesions in patients presumably free of syphilis respond at times in an equally prompt manner.

Inoculation of animals susceptible to syphilis as well as those to tuberculosis offers a more hopeful method of study than has been heretofore pursued. This method was employed in studying a case of sarcoid in a syphilitic patient seen in the Peiping Union Medical College. Treponema pallidum was isolated from a rabbit inoculated with the sarcoid tissue, but no acid-fast bacilli were demonstrated in the tissues examined from 2 guinea pigs inoculated with the same material.