Medical morbid anatomy and pathology / by Hugh Thursfield and William P.S. Branson.

  • Thursfield, Hugh.
Date:
1909
Catalogue details

Licence: In copyright

Credit: Medical morbid anatomy and pathology / by Hugh Thursfield and William P.S. Branson. Source: Wellcome Collection.

    41/302 page 29
    about 3 mm. long and consists of two segments. By one of these it is attached to the wall of the brood-capsule ; the other is free, and is armed with four suckers and a ring of hooklets, each shaped after the fashion of a shark’s tooth. Should a scolex gain entrance to the intestine of one of the Canidae it developes into the adult worm. Hydatid cysts may be single or multiple. The parent 1st gallery, cysts, when proliferative, may contain an indefinite number of 2232/z daughter and grand daughter cysts. These successive repro- ductions are accomplished either by invaginations of the endo- cyst which become vesicular, or by a cystic development of the scolices and brood capsules. The ectocyst is tough and elastic, and presents under the microscope a laminated appearance. The endocyst is of a pearl-white colour and gelatinous in consistency. Hydatid fluid from such cysts is clear and of a specific gravity ranging from 1002 to 1010. During the life- time of the parasite the fluid contains sodium chloride in abundance, but no albumin. After death of the cyst its fluid becomes albuminous and generally contains detached hooklets, 1st gallery, scolices, and brood capsules. The tissues in the immediate 2233A neighbourhood of the cyst undergo a slow fibrosis by which means an adventitious capsule appears around the ectocyst. Fate of the cysts.—It is probable that hydatid cysts may live for years unaltered. They may rupture during the life- time of the parasite, producing secondary cysts along the path of the escaping fluid, unless the primary cyst be sterile, in which case there may be no resultant lesion. Frequently they undergo spontaneous death from causes little understood. In this case one of two events ensues. (1) Absorption.—The contained fluid of both the parent and daughter cysts becomes albuminous and subsequently inspis- sated by the absorption of its fluid ingredients, forming ultimately a putty-like mass. This shrinkage is accompanied by collapse of the walls of all the cysts concerned. They become folded upon themselves and their diminishing contents, 1st gallery, and give to the cut surface of the dead cysts an appearance of 2230.8 gelatinous stratification. In course of time calcareous salts are 2230D deposited in the adventitious capsule and in the dead remains 1st gallery, of the pamsite. 2233B (2) Suppuration.—Bacterial infection may convert the cyst-
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