The rather lengthy articles by Fano* and Darier* are extremely helpful in dealing with the problem of the border line conditions between the sarcomata and sarcoids.
The Boeek-1 type of sarcoid is probably the best known and the most often diagnosed. It may occur as one or more large nodules, as numerous papules, or in infiltrated placques, usually developing upon the face. back, shoulders, or arms. There are practically no subjective symptoms, and the general health is unaffected. The nodules are pink or purplish in color, and often show dilated peripheral vessels, and there may be slight scaling. To the touch they are firm and elastic, but there is no deep infiltration. The lesions run a chronic course and never ulcerate. They may involute spontaneously.
Histologically, the sections show sharply circumscribed, deep-seated nodules, composed of epithelioid cells, filling the perivascular lymph spaces. At the periphery one may observe lymphocytes and a few giant and plasma cells. There is no evidence of caseation necrosis, although Boeck considered the lesions to be tuberculous in origin.
The lesions involute under prolonged administration of arsenic.
The type of sarcoids described by Darier and Roussy* is rare and occurs only upon the trunk. There are found lesions of about 1 to 5 cm. in diameter, distinctly round or oval. The nodules are composed of epithelioid cells and lymphocytes and numerous giant cells. The changes are less circumscribed than in the Boeck type, and at times seem to be distinctly infiltrating.
*Fox and Wile: Jour. Cut. Dis.. 1911, xxix, 375.
*Fano: Arch. f. Dermat. u. Syphil.. 1907, lxxxiii, 33, 225. 427.
*Darier: Monatsh. f. prakt. Dermat., 1910, 1, 419.
*Boeck: Jour. Cutan. and Gen.-Urin. Dis., 1899, xvii, 543.
Arch. f. Dermat. u. Syphil., 1905, lxxiii, 71. "Darier et Roussy: Ann. de Dermat. et Syphil., 1904, v, 144, 347.
The last type, suggested by Darier, resembles the erythema induratum of Bazin; in fact, the following name has been suggested, "sarcoides noueuses et nodul-aires des membres.,, The lesions usually develop upon the legs of adult women, and present reddish or purplish nodules or infiltrations. It is very difficult to separate this group from true cases of erythema induratum, especially as this type of sarcoids may occasionally ulcerate.
Darier especially points out that all cases of sarcoids do not run true to form, and that one case may show features of several of these groups, either clinically or histologically.
In regard to etiology, there are two views-one that the affection is of tuberculous origin, and the other that it is not. In favor of the tuberculous etiology may be cited the microscopic findings, the epithelioid and giant cells, although the author by no means admits that the presence of giant cells makes a diagnosis of tuberculosis certain, for they can be found in almost any chronic inflammatory condition of the skin, even down to acne vulgaris. Winckler,* in an analysis of seventeen cases, found evidence of tuberculous deposits in the body in six cases, and that about ten cases out of thirty-one reacted positively to tuberculin, a figure not much more than the general average of supposedly healthy persons. A positive inoculation experiment has been recorded by Morawitz* On the other hand, Kren and Weidenfeld* made inoculation experiments in two cases with negative results. Histologically and clinically, there is no evidence of caseation or necrosis, which fact is very unlike those usually observed in tuberculosis of the skin. Arsenic will cure sarcoids and will not cure tuberculosis.
From the standpoint of differential diagnosis, it is at times extremely difficult to exclude sarcomatosis cutis, only the course of the disease serving to do that. Leukemia cutis, leprosy, and syphilis can be differentiated by the various laboratory tests in case of doubt.
The prognosis for both life and the local betterment is good. Arsenic has a remarkable effect, although it must frequently be used over a long space of time. Darier thinks that the x-ray, calomel, and tuberculin are also useful.
*Winkler: Arch. f. Dermat. u. Syphil., lxxvii, 3.
*Morawitz: Arch. f. Dermat. u. Syphil., 1910, cii, 121.
*Kren and Weidenfeld: Arch. f. Dermat. u. Syphil., 1909, xclx, 79.