128 



PRODUCTS, ADVENTITIOUS. 



presumed to be anatomically so, and con- 

 founded with Growths composed of true erec- 

 tile tissue. 



Allied, at least in its functional characters, 

 to angeiectoma, is the growth composed of 

 true erectile (or cavernous) tissue. Soft, 

 doughy, pseudo-fluctuating, pulsatile, erectile, 

 the occasional seat of tactile fremitus and 

 blowing murmur, occurring generally in a 

 single, but sometimes in many spots, com- 

 monly cutaneous or sub-cutaneous, but liable 

 to grow in deep-seated parts, congenital or 

 accidental, rarely exceeding a Seville orange 

 in size, and often very small, traceable in rare 

 cases to the influence of pressure or other 

 external injury; sometimes of rapid, oftener 

 of very slow progress; the true erectile tu- 

 mour has a structure perfectly assimilable to 

 that of cavernous tissue, and, like this, a 

 structure not yet thoroughly unravelled. 

 On section these growths (fig. 94) exhibit 



Fig. 94. 



Section of a true erectile growth. (U. C. Mus.} 



on a coarse scale the interlaced columnar 

 appearance of erectile tissue : the trabeculae 

 vary in thickness and density, and are pro- 

 vided with minute vessels ; the hollow spaces 

 between these are shallow or deep, narrow or 

 broad, quadrangular or triangular, and com- 

 municate with each other. Microscopically 

 the trabeculae are found to be composed of 

 fasciculated, cellular or fibrous (in very rare 

 instances of intermingled elasti^ fibrils, coated 

 with tesselated epithelium, which conse- 

 quently also lines the hollow interspaces. 

 When these trabeculae are in process of 

 growth they contain fusiform cells. 



Such Growths are never encysted, but they 

 sometimes acquire a secondary capsule of 

 condensed cellule-fibrous membrane. It is 

 said they are sometimes lobulated, a condition 

 in which we have never seen them. They 

 are rapidly regenerated if imperfectly removed. 

 Particularly when connected with the skin, 

 erectile structures may become the seat of 

 cancerous formation. 



Erectile Growths generally appear in super- 

 ficial parts, the skin and subjacent cellular 

 membrane ; the mucous membrane of the 

 anus (as a rare variety of pile) ; the gingival 

 membrane (?) ; the tongue (Brown, in Lancet, 

 1833). Mr. Listen (Med. Chir. Trans, vol. 

 xxvi.) describes an erectile tumour (Univ. 

 Coll. Mus.) seated in the substance of the 

 semi-tendinosus muscle; Andral (An. Path.i. 

 p. 463) speaks as if the structure were not 



uncommon in the intestines, but we have 

 never seen it here; Lobstein describes it in 

 the liver (?) ; Rayer (Maladies des Reins, 

 t. iii. p. 612) in the kidney. 



5. MELANOMA. 



Melanic cell-pigment, as described in a pre- 

 vious page (p. 116), may be deposited in the 

 substance of various Adventitious Formations, 

 of Deposits (e. g. Tubercle), of Growths 

 (e.g. Cancer), and of Pseudo-Tissues (e.g. Os- 

 siform structure). Growths, more or less deeply 

 tinged by its presence, have been distinguished 

 as a special class of products under the title 

 of Melanotic Tumours or Melanomata. Whe- 

 ther they have any real claim to such distinc- 

 tion will be best argued, when we have, in as 

 few words as possible, glanced at the struc- 

 tural characters of Tumours of black colour. 

 These tumours are, in some instances, sar- 

 comatous, in others composed mainly of en- 

 larged vessels, in others cystomatous, in others 

 fibrous, the pigment being deposited be- 

 tween or within the convoluted fibres or ves- 

 sels of the mass. But no growth contains 

 melanic pigment so frequently as cancer. 

 Studded in points through the cancerous 

 masses, accumulated in lumps or equably in- 

 filtrated through their substance, the cell- 

 pigment gives them a peculiar dark colour. 

 This discolouration is by far the most common 

 in the encephaloid species, and occurs most 

 frequently in cancer of the eye, skin, and 

 liver, but is not peculiar to any locality.* 



Misled by the frequency of this discoloura- 

 tion of cancerous tumours, various writers have 

 endeavoured to rank "Melanosis" generally 

 as a .cancerous disease. Lorinser, Laennec, 

 Dupuytren, Alibert, Meckel, vonWalther, and 

 Cruveilhier, for instance, take this view of its 

 nature ; and more recently Miiller has de- 

 scribed " carcinoma melanodes" as one of his 

 six species of cancer, holding as distinct and 

 individualized a place in the class as Ence- 

 phaloid or Scirrhus. The following reasons 

 lead us to dissent altogether from these doc- 

 trines. (1.) That melanic pigment should in 

 itself constitute cancer is an impossibility ; it 

 never even forms a stroma, as the cells con- 

 tinue permanently free. (2.) The stroma of 

 many melanic tumours (as of those above 

 referred to, fibrous, &c.) is perfectly distinct 

 in its physical and chemical characters from 

 all cancerous stromata. (3.) The microsco- 

 pical characters of the pigment-cells and gra- 

 nules are the same in tumours of cancerous 

 nature and in non-cancerous growths. (4.) 

 Melanic tumours, when free from acknow- 

 ledged cancerous elements, cause no special, 

 local, or general symptoms. (5.) When me- 

 lanic tumours give rise to the symptoms of 

 cancerous disease, their solid stroma is found 

 to be composed in whole or in part of ence- 

 phaloid, scirrhus, or colloid. (6.) Neither the 

 local nor general symptoms of cancers are 



* The Univ. Coll. Museum contains a model of 

 melanotic encephaloid of the vertebrae and spinal 

 meninges. 



