Page:Encyclopædia Britannica, Ninth Edition, v. 18.djvu/390

 368 PATHOLOGY remained over from the foetal development, persisting in their embryonic characters while all else around them had assumed the characters of maturity. For the arguments and illustrations of this hypothesis the reader may refer to the section beginning at p. 622, vol. i., of Cohnheim s Vorlesungen iiber allgememe Pathologic. It must suffice to say here that groups of resting embryonic cells in the various organs and parts of the body, or embryonic rudi ments in the sense of Cohnheim, are not known to exist at all generally. That which we are well assured of is an indwelling power of all the mesoblastic tissues to revert to embryonic characters, the spontaneity of the tissues never quite worn out, or the memory of development more or less deeply rooted in them to the end of life. From this point of view we have traced the process of repair, finding a developmental analogy even for pus. From the same point of view we have now to consider certain kinds of new formation as arising, not to make good defects, but under an erratic impulse, or in the course of an erratic spontaneity. Congenital tumours have always been regarded as errors of development, and it will be con venient to select a simple congenital tumour to begin with. Fibroma. Fibroma. The texture drawn in the figure (fig. 19) occurred in a tumour of the x s x^&amp;lt; - ^. TV^ //;-/-- - *,, /. ^-/ / ^-^^ -*= back of the neck vr: ^ ^. % .T ^:*&amp;gt;^.?- t-.j-^.^. ~^&amp;lt;~/^ ^fe ^-. in aj r oungchild ,V;. C - r*J^ ^.^V-ff? ^^ &amp;lt; ,- &quot;- ^ ^, -, T x c &quot;^?;- having been &quot;&amp;gt;f ..&quot;-^ ^f^T^Y? ~* ^ * {: &quot;&quot;? ? 3 ^ ^ ^ there since ^ &amp;lt;&amp;gt; - ... ^~-*_.&quot;? ~- &quot; &&quot; - ^ &quot;.&quot; Z^Z&p ^f. birth. It is a V; - :. -. : /-&amp;lt;__. - X : : ~; -/ j. ~ ^ &amp;lt;~*^ &? !$/ fibroma, and *.;, &quot;&amp;gt;:&quot;. i&&^$* %^&t&$$fy consists essen- %, /. I&quot;? ?* /- -^ . ^/5/ &quot; - -^ : / ^ tiallyof bundles t v : ; l : rV .; - .-. . - - - &quot;-.&quot;^/ of wavy fibres, ? , ..&quot;.. ..&quot;, *&quot;. / ; ; - .. /- . &quot;ii ^V-&amp;gt; ;^ crossing or de- .?;. Miffi * ,* *, C: *$^ ?ffi, ^-/f^/-^ -^&amp;gt;- &quot;^^ cussating in di- ffli si//A / % *e ^^ f^~t ~,t #/ &&amp;lt; ? v ^ c ViR^&amp;lt;^- rection, some- / !) &quot; . &quot;/ d %Vi &amp;lt; r ^ &amp;lt; ! 1 f/^ . / ^ .^ .-S, times thick &amp;lt; ;,} f &amp;gt; &amp;gt;, &quot; ^5&quot;- ~^ . &quot;* ^ ^ a;r &amp;gt; . l bundles, some- &amp;gt;^ . o[! _ ^/ ~ - .^&quot; /^ / . = ^^ ^ l- times only a few &quot; ; ~ ?. &quot; ? ...-&amp;lt;. V-? *, */ ; , /./ .??&amp;gt;; fi} I strands, . the ;, ,:,&amp;gt;V c -.- |, ^itj^^^^^^^^^^^^ wliole forming &quot;M ^ - &quot; W& /. a dense warp- FIG. 19. Congenital fibroma from a child s back; warp- and-woof tex- and -woof fibrous texture, with embryonic nuclei; bundles ture The ne of fibres seen also in cross-section. culiarity is that such a tissue should have formed under the skin as a tumour or lump the size of a hen s egg ; spread out in thin layers, the same warp-and-woof texture of fibres occurs naturally in the aponeuroses and the sheaths of muscles, and in other fibrous membranes, such as the dura mater; and the large number of nuclei among the fibres, as shown in the figure, would be appropriate to the fibrous tissue at the early period of life to which the tumour belonged. At various centres these embryonic cells had developed into fat-cells, so that the tumour may be called a fibro-lipoma. The tissue has increased in three dimensions, and so has resulted in a palpably distinct object in the body, which could be dissected out from among the surrounding structures as an individual thing. The overgrowth had taken place probably in one of the aponeu roses of the trapezius muscle, and the noteworthy point is that it has faithfully adhered to the warp-and-woof texture proper to the tissue on which it is based. The new formation possesses length, breadth, and thickness, and its fibres are interwoven in the three dimensions as if it had been constructed at some unusual kind of loom. The same interlacing of ./././ 4 -. ^, E,,,^/ bundles of wavy fibres is found very .;/. commonly in the fibromata, their. V /&amp;lt;. / * favourite seats, besides the flat fibrous ./.., sheaths, aponeuroses, and mi:in- ./ // branes, being the uterus and it- ,; &quot; appendages, where the tumours may .,. be stalked or sessile. Sometimes tin-, ; fibres are concentrically arnni, &amp;gt; /,&amp;lt; / round a number of centres, or the l, ,V&amp;gt; .&quot; yy bundles may pursue a sinuous course. One variety may be specially ni ii- /. -^ tioned as exemplifying a modification ? .I -fjjfjl of fibrous structure which is often met I -tf^&quot;&quot; with in various normal and patholo- ! gical processes. In this modification ***** ^-&quot; -&quot;- the fibres become as if fused into Fli; - 20. Recurrent ossifying broader homogeneous bundles, the fibroma of lower jaw. nuclei being left lying as if in spaces or holes in a structureless celluls tumoi; ground-substance. This variety of fibroma is generally found in the bones of the jaws ; it may be ossified at some points, the nuclei becoming the bone-corpuscles, and the homogeneous ground- substance becoming impregnated with the earthy substance of bone. The accompanying figure (fig. 20) is drawn from a preparation of a fibrous tumour, ossified in part, within the medullary space of the lower jaw in an adult. It had been removed once, and grew again (recurrent fibroma or fibroid). &quot;Where the modification takes the direction of an increase of Fib the cells at the expense of the fibres, we have a fibro -cellular tumour. The tumour is com posed of elon gated elements, which are vir tually nucleated cells with very long bodies, amounting al most to fibres. The figure (fig. 21) is made from an extensive tumour deeply FIG. 21. Fibro-cellular tumour ; decussating bundles. FIG. 22. Tumour composed of small spindle-cells decussating bundles. seated in the carotid region of the neck in a woman aged twenty-two. There is nothing more remarkable in all these varieties of tumour Sarco than the constancy of the warp-and-woof texture, and we shall find that the same is an important characteristic of the class of tumours where the fibrous structure is wanting and everything becomes cellular. Tumours of the latter kind form the group of sar comata or flesh-like ^^^rvrx^^^O* tumours. Proceed ing from the fibro- cellular tumour last mentioned and sketched, we come to the variety of spindle - celled sar coma, in which the cells differ from the fibro -cellular elements of the former, chiefly in the greater promi nence of the nuc leus and the greater delicacy of the tapering prolongation of cell- substance. It is sometimes called a small spindle-celled sarcoma. The figure (fig. 22) shows the structure to be purely cellular, with out any fibrous supporting tissue. In the cross-section the spindle- cell appears as a small round cell. In the sarcoma ivith large spindle-cells we have a form of tumour not uncommon in certain regions of the body, often associated with brown pigmentation, and very generally malignant in its course. One common seat of it is the choroid coat of the eye, where large pig- mented cells, both spindle-shaped and branched, exist naturally. An other common seat is the subcutaneous, ,. ., ..^^v^,- :stxs - tissue, where pig-^v^ ^Jb:J_*^ mentation is not a normal occurrence. The illustration (fig. 23) is taken from a case where there was, how ever, brown pig mentation of the skin for a considerable distance round the tumour. The situation was the shin, the common seat of chronic ulcers, and the tumour seemed to have begun in the scar-tissue of an ulcer of that kind. The cells are very large spindle-like elements grouped in decussating bundles, the distribution of pigment being partial (omitted entirely in the cut), and not uncommonly confined to the narrow bands of cells separating two broader or thicker bundles. The developmental or embryonic character of these cells is suffi ciently obvious; but the occasion for their reappearance in mature life is not so clear. For the particular ease of tumour over the shin FIG. 23. Tumour composed of large spindle-cells in decussating bundles.