ACTINOMYCOSIS. 



679 



incision exhibit a lardaceous appearance. On section it may appear 

 that the lesion is confined entirely to the bone, though this is excep- 

 tional (Fig. '274). Ordinarily the neighbouring tissues are also de- 

 stroyed, and not infrequently there is communication with the ex- 

 ternal air. Sections then display a fungoid tissue, interspersed with 

 perforated lamellfe of bone and lardaceous tissue containing cavities 

 crammed with actinomyces. 



The lesions in the parotid regions, the neck or other parts attacked 

 always present the same appearance, viz., wide, tortuous, bifurcated 

 fistulffi, with exuberant granulations both in the direction of the cavi- 

 ties and of the exterior, together with lardaceous induration of the 

 tissues and abundant foetid liquid 

 pus. 



When it affects the tongue the 

 parasite is to be found in the sub- 

 mucous region, where it causes 

 little swellings, which, when super- 

 ficial, rapidly undergo ulceration. 

 The subjacent regions, the inter- 

 stitial connective tissue, and the 

 muscular tissue become infiltrated, 

 hardened and progressively scle- 

 rosed. The tongue is gradually 

 hypertrophied, and soon it becomes 

 as hard as wood, whence the term 

 "wooden tongue." 



Actinomycosis of the lung 

 may easily be mistaken for tuber- 

 culosis, for the centres, although 



usually confined to one lobe, may also be disseminated. The lesions, 

 however, are surrounded by an abundant fibro-sclerous inflammatory 



tissue. 



In the abdominal cavity, particularly in sows, actinomycotic lesions 

 occur as little masses varying in size between that of a pea and that 

 of a haricot bean, attached to the epiploon and peritoneum and filled 

 with pus containing mycosic grains. 



Diagnosis. Actinonfycosis is usually easy to recognise, both on 

 account of the special character of the lesions and the presence of 

 the Uttle grains formed by the parasite. The practitioner will rarely 

 fail to recognise at once the signs of actinomycosis of the jaw, but 

 actinomycosis of the tongue is more apt to be mistaken for deep-seated 

 sclerosing glossitis, although a careful examination will always enable 

 the different symptoms to be distinguished. 



Fig. 275. 



— Highly-magnified clump 

 of actinomyces. 



