. The elements of pathological histology with special reference to practical methods . le extends (reticulated ticberclc ; Fig. 61, d). A furtherresult is usually the emigration from the neighbouring blood-vesselsof leucocytes, mostly of the mononuclear variety, w^hich collect asa rule at the periphery of the nodule (Fig. 61, a), but may alsopenetrate into its interior; and when the emigration takes placevery early, or at all events to an excessive degree, nodules occurwhich are composed exclusively of lymphoid cells {lymphoid tubercles).In the centre of tubercles, especially when slow-growing
. The elements of pathological histology with special reference to practical methods . le extends (reticulated ticberclc ; Fig. 61, d). A furtherresult is usually the emigration from the neighbouring blood-vesselsof leucocytes, mostly of the mononuclear variety, w^hich collect asa rule at the periphery of the nodule (Fig. 61, a), but may alsopenetrate into its interior; and when the emigration takes placevery early, or at all events to an excessive degree, nodules occurwhich are composed exclusively of lymphoid cells {lymphoid tubercles).In the centre of tubercles, especially when slow-growing and poor 132 THE VEGETABLE PARASITES in bacilli, gia7it cells (Fig. 61, c) are tolerably often found; that is,polynuclear cells which are formed by continued proliferation of thenuclei without subsequent division of the cells {giant-celled tuhercles). When the tubercle has attained a certain size it caseates fromthe centre outwards (Fig. 61, e), its cells dying and shrivelling up(p. 63), until finally a molecular detritus is left which at first B • ,•• * * SV • • • 1 t. Fig. 61.—Two Young Tubercles of the Spleen in General Acute Miliary 240. (Hsematoxylin and eosin.) A, Giant-celled tubercle; B, Tubercle with commencingcaseation ; a, Leucocytes ; b, Epithelioid cells with elongated nuclei; c, Giant cells; d, Connective-tissue reticulum; e, Caseation. stains even more deeply than normal, but at a later stage will nolonger take up colour at all. As the giant cells are also affectedby the caseation, but at first only in their centre, there is veryoften seen in them a perfectly characteristic marginal arrangementof their nuclei. New nodules soon develop in the neighbourhood of the first, andunite with one another to form ever-enlarging masses and foci, visibleeven to the naked eye {conglomerate tubercles). When the tubercleslie near a free surface or natural cavity, caseation is, as a rule,eventually succeeded by softening and breaking down, so that ul
Size: 2077px × 1203px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectpatholo, bookyear1895
