130 



PRODUCTS, ADVENTITIOUS. 



" become cancerous," in the erroneous lan- 

 guage of their describers ; we have never seen 

 or read of a satisfactory example of cancerous 

 formation, from a basis of lipoma. Fibrous 

 thickening of the cellular septa of the growth 

 is not uncommon ; but a true fibroma is 

 never evolved from a lipomatous tumour. 

 Absorption of the fat may be effected by arti- 

 ficial pressure ; the residual cellule-fibrous 

 structure forms a more or less dense mass. 



Lipoma with excess of cell ulo- fibrous stro- 

 ma, much firmer than the simple variety, and 

 more frequently invested by a pseudo-cyst, 

 has been described under the names of Adipose 

 Sarcoma, and Lipoma Mixture. 



Lipoma has sometimes a semi-transparent 

 almost gelatiniform look, the cause of which 

 is not clear. 



Miiller proposes the title of lipoma arbores- 

 cens for certain rare adipose formations, 

 found in the joints. They originate behind 

 the free part of the synovial membrane, pro- 

 trude into the joint, and form tufts, nodulous 

 at the ends. They are said to be most com- 

 mon in the knee-joint. The pleural lipoma, 

 just referred to as having occurred in our own 

 practice, might be accredited to this variety. 



$ 2. STEATOMA. 



There is a variety of fatty growth of greater 

 density and solidity than lipoma, close in 

 grain, inelastic, opaque, having the aspect of 

 suet or sometimes of putty, wholly unlike 

 natural adipose tissue. Such tumours, to 

 which the name of steatoma is given, are 

 composed of fat, soluble in boiling alcohol, 

 non-vesicular, granular, and amorphous, and 

 aggregated into masses without the interven- 

 tion of cellular tissue. These accumulations 

 sometimes acquire great bulk ; we have seen 

 them in the mesentery, testicle, and mediasti- 

 num. 



3. CHOLESTEATOMA. 



See CHOLESTERIC FATS (p. 94). 

 OF GELATIN BASIS. 



1. FIBROMA. 



Fibrous Growths appear naturally to affect 

 the spherical form : they may, however, be 

 accidentally flattened (as in the walls of the 

 uterus, during the advance of pregnancy, 

 Univ. Coll. Mus.) ; pedunculated (seep. 122) 

 under the mucous membrane of the nose and 

 uterus ; or nodulated from having two or more 

 centres of development. They may be smaller 

 than a pea (in the dura-mater for instance); 

 or, especially when developed under the peri- 

 toneal coat of the uterus, exceed the head of 

 an adult in size : tumours of this kind have 

 been known to weigh 25, 30, 35, and 39 

 pounds. Their external surface is naturally- 

 smooth and even ; loose filaments of cellulo- 

 vascular tissue form their common material 

 of union with adjoining textures ; in some 

 cases the connection is rendered unusually 

 intimate by exudation-matter. (See p. 125.) 



On section the colour of these growths is 

 generally found to be greyish-white, the grey- 

 ish colour being that of the intrastromal matter, 

 the white (which may be dull or glistening) that 

 of the stromal. Less commonly fibroma has 

 a reddish hue. The consistence of the mass 

 varies with its colour : the greater the white- 

 ness, the greater the density, specific gravity 

 and tenacity of the tumour ; the reddish 

 coloured growth is comparatively soft and 

 yielding. 



The constituents of fibrous tumours visible 

 with the naked eye, are white bands ; a ma- 

 terial interposed between them of darker 

 colour, less opaque, less dense, and less 

 manifestly fibrous ; and, in comparatively rare 

 cases, vessels, congregated in the main to- 

 wards the periphery of the mass. The arrange- 

 ment of the white bands and of the enclosed 

 darker substance is peculiar: the bands follow 

 an irregularly curvilinear direction ; the loculi 

 hence affect the spheroidal or oval shape. 

 This character helps to distinguish fibroma 

 from scirrhus with great excess of fibrous stro- 

 ma; in such scirrhi the fibres always exhibit 

 a tendency to rectilinear arrangement. By 

 firm pressure a transparent, pale straw coloured 

 (never lactescent), and glutinous fluid may 

 be forced from a fibrous tumour : its quantity 

 is very small, and it may be infiltrated through 

 the growth or accumulated in spots. 



Microscopically these growths are found to 

 consist of fasciculated and intertwined fibres, 

 less undulating in direction and less clear in 

 outline than those of natural fibrous tissue, 

 arranged parallel to each other, and studded 

 or not with minute inequalities, produced by 

 the still remaining nuclei of original cells. In 

 the soft fibrous tumour this filamentous ele 

 ment is the same in character as in the hard ; 

 but it is less abundant, less closely set, and 

 scarcely fasciculated : in this variety, too, it 

 is more common than in the hard, to find 

 cells with granular contents, some of them 

 assuming the fusiform shape. We have oc- 

 casionally seen fat-granules in these tumours ; 

 but fat is never one of their predominant ele- 

 ments. 



When submitted to ebullition, the entire mass 

 of a fibrous growth is converted into a jelly 

 (glutin), with the exception of a very minute 

 quantity of protein substance, derived, pro- 

 bably, from associated blood : the walls of the 

 few cells, such tumours contain, are insuffi- 

 cient to account even for that minute quan- 

 tity. Their saline constituents are, in various 

 proportions, those of the blood. Valentin 

 attempts to show that fibrous tumours of the 

 uterus are sometimes composed of fibrin : 

 doubtless, as we have already explained (p. 

 126) haematomata of the uterus occur, and 

 may undergo evolution into fibrous tumours : 

 but we altogether discredit the alleged fact, 

 that tumours exhibiting the microscopical 

 constitution of fibroma, are ever of protein- 

 basis. 



The nature of fibroma leads it simply to 

 enlarge, without change in, or around, itself. 

 Some alterations of texture are so common, 



