126 



PRODUCTS, ADVENTITIOUS. 



ing, gives it this character. A haematoma 

 is rarely encysted ; for though nothing is 

 more common than the formation of a cyst 

 round effused blood (apoplectic cyst) as a 

 general fact, yet this process is rarely wit- 

 nessed, where the progress of absorption has 

 been of the kind to produce a haematoma. 



Haematomata may probably form wherever 

 blood, thrown out from the vessels, is re- 

 tained. Thus (1) they are seen in the serous 

 cavities, as the peritonaeum and pleura, where 

 they have more than once been found in the 

 stages of transition ; and in synovial cavities, 

 where, as John Hunter long since maintained, 

 they frequently form the so-called " loose car- 

 tilages" of joints. (2) Amid membranous 

 structures, as for instance, under the choroid 

 coat, where they have been frequently mis- 

 taken for carcinoma ; into the great cavity of 

 the arachnoid (Univ. Coll. Mus.) a not un- 

 common seat ; between the arachnoid and 

 dura mater of the skull, where, we feel posi- 

 tive, they have occasionally been the origin of 

 minute fibrous tumours ; under the mucous 

 lining of the uterus, where a similar destiny 

 sometimes awaits them; under the periosteum, 

 either when the blood has flown through the 

 influence of external injury, or through the 

 influence of causes, partly traumatic, partly 

 spontaneous, as in that singular affection of 

 new-born infants cephalhsematoma. (3) 

 In parenchymatous organs, as the brain, the 

 spleen, the kidneys, the lung (in all of which we 

 have repeatedly seen them), and more rarely 

 in the mamma, where they have often, clin- 

 ically, played the part of cancers. (4) In 

 the cellulo-muscular structures of the limbs, 

 as the result of contusions or spontaneous 

 haemorrhage. (5) In the proper substance of 

 certain new products, especially encephaloid 

 cancers. (6) In cavities accidentally formed 

 in the tissues, as in tuberculous cavities in 

 the lung. (Univ. Coll. Mus.) 



Various changes of deep interest may occur 

 within the substance of a haematoma. Unsup- 

 plied with vessels, as it commonly is, it cannot 

 be the seat of interstitial haemorrhage ; but 

 blood may nevertheless infiltrate its substance 

 derived from the ruptured vessels of surround- 

 ing .textures, just as extra-vascular tissues 

 may become infiltrated with exudation-matter 

 produced by inflammation, not in them, but be- 

 side them* Saline precipitation is a common 

 occurrence ; such is often the origin of ossiform 

 particles or masses in the brain ; of similar 

 masses in advanced cephalhasmatoma -j- ; and 

 such (as elsewhere shown by us) is almost in- 

 variably the source of free calcareous and ossi- 

 form products in cancer : the changes con- 

 cerned in the production of a phlebolith are one 

 by one gone through. That melanic pigment 

 may form in haematomata appears extremely 

 probable, from certain observations which we 

 made several years ago on some specimens of 

 melanic tumour ; full reference to these will be 



* A remarkable example of haemorrhage into a 

 haematoma of the brain lately occurred in our wards 

 in University College Hospital. 



f See this word, Cyclopaedia of Surgery, vol. i. 



found in the section on Melanoma. We have 

 in a previous section spoken of the doubt still 

 hanging over the question of the possible evo- 

 lution of simple effused blood into Forma- 

 tions of definite structural characters. The 

 question appears to be all but absolutely 

 decided in the affirmative by a tumour now 

 before us (Univ. Coll. Mus.), in the substance 

 of which the transition from the characters of 

 haematoma to those of fibrous tumour, is per- 

 fectly traceable in point of colour, consistence, 

 and textural arrangement. Bone-formation 

 may take place from blood effused in localities 

 where a tendency to such formation naturally 

 exists, and where formative life is active. 

 Thus, in the instance of sub-pericranial ce- 

 phalhaematoma, the smooth gelatinous-looking 

 membrane, which invests the blood, may be- 

 come so perfectly ossified, that it has, in this 

 state, been evidently mistaken by some ob- 

 servers for the outer table of the bone, and a 

 figment, in the shape of interstitial or diploic 

 cephalhaematorna, invented to meet the dif- 

 ficulty. Even in the centre of the fibrinous 

 residue of this effused blood actual bone has 

 sometimes been seen. 



Concerning the vascularization of blood in 

 substance we have already given our opinion. 

 Haematomata in the brain have been found dis- 

 tinctly vascularized in cases where there was 

 no evidence that plastic lymph had been 

 added to the extravasated blood ; and M. Louis' 

 description, already referred to, of a vascu- 

 larized coagulum in a tuberculous excavation 

 of the lung is peculiarly satisfactory. 



Blood retained in its proper canals may 

 coagulate and undergo various changes. In 

 the arteries, cellulo-fibrous evolution and cal- 

 cification occur in stagnating blood without 

 the intervention of an inflammatory process : 

 in the veins we have seen vascularized coagula 

 injected ; and the formation of phleboliths 

 and arteroliths illustrates saline precipitation. 

 Vascularized coagula in the heart have been 

 described by Rigacci, Burns, Bouillaud, and 

 others. 



2. SARCOMA. 



Simple sarcoma (crap, flesh), or cellulo- 

 vascular growth, presents itself as a mass of 

 variable dimensions, those of a hazel-nut 

 and of a cocoa-nut are the extremes we have 

 seen. Of oval or, less commonly, spherical 

 outline, its surface may be even and tole- 

 rably smooth, or nodulated (U. C. Mus.). 

 Sarcoma is particularly elastic ; varies much 

 in consistence and density ; breaks sharply 

 under the nail, in the direction of its fibres ; 

 is rather crisp than tough, unless in the site 

 of its cellulo-fibrous locular walls ; exhibits 

 on section a tolerably smooth, glossy, semi- 

 transparent surface, such inequalities as exist 

 depending upon the unequal elasticity of its 

 containing and contained elements ; is free 

 from greasiness, either to the look or feel ; 

 is usually of pale yellowish or buff colour in 

 the main, presenting here and there reddish 

 or more rarely lilac-tinted spots, or striae, or 



