log Postgrad Med J: first published as 10.1136/pgmj.26.293.109 on 1 March 1950. Downloaded from Protected by copyright. FIG. 5. Acoustic Schw annoma. THE PATHOLOGY OF INTRACRANIAL TUMOURS By DOROTHY S. RUSSELL, M.D.(Lond.), Sc.D.(Camb.), F.R.C.P.(Lond.) Professor of Morbid Anatomy, London University. From the Bernhard Baron Institute of Pathology, the London Hospital http://pmj.bmj.com/ The following account of the pathology of that involve the ethmoid cells and orbital region intracranial tumours, first published in 1939, has are of importance (Cushing, 1927) since they may been revised. As before, limitations of space pre- project into the anterior fossa causing cerebral clude- more than scanty reference to the rarer compression. tumours, but references are provided for readers 2. Chondrotrata and chondrosarcomata may arise who desire greater detail. from the bones preformed in cartilage at the base on September 30, 2021 by guest. of the skull and project into the middle or posterior A. PRIMARY TUMOURS fossae, or both. In two examples of myxochondro- sarcoma, examined at the London Hospital, a 1. Skull smooth lobulated mass of brittle, translucent grey Primary tumours of the vault or base of the tissue projected from the dura into the middle and skull are rare. Cushing (1932) records 14 examples posterior fossae of one side, invading or dis- only in his series of 2,023 verified cases of intra- cranial tumours.* * This series includes 4.2 per cent. of secondary i. Osteomata are composed either of dense tumours, obviously too low a figure because such cases ivory or spongy bone. The ivory variety pre- tend to be excluded from any neurosurgical clinic. In addition 2.2 per cent. of cases are listed as ' inflam- dominates in the skull where it usually protrudes matory tumours,' i.e. granulomata. In the following as an exostosis from the inner or outer table or pages Cushing's figures have been adjusted so that the projects into one or more of the air sinuses. Those percentages refer to primary intracranial tumours only. I0 POSTGRADUATE MEDICAL JOURNAI, March I950 Postgrad Med J: first published as 10.1136/pgmj.26.293.109 on 1 March 1950. Downloaded from IO :S i Protected by copyright. FIG i.-Chordoma. H. & E. X 265. FIG. 2.-Meningioma. placing the pituitary body and indenting the tumours and are most frequent in the middle and adjacent temporal lobe and brain stem. In both later decades The regions in which most are death was due to subdural haemorrhage. In one found are (a) parasagittal, (b) over the cerebral subject Ollier's disease was also present. Micro- convexities, especially the frontal region, (c) scopically the tumours are composed of typical olfactory groove, (d) sphenoidal ridge, (e) tubercu- and atypical cartilage, the stroma being largely lum sellae, (f) near the lateral sinuses. The fre- myxomatous and focally calcified. Chondromata quent situation of these tumours in the neighbour- may also arise from the vault, especially the hood of the arachnoid villi, and their histology, parietal bone (see Chorobski, et al., I99 for strongly support the theory 'that they are of review). arachnoid origin. The finding of tumours at http://pmj.bmj.com/ 3F.Chordoma, derived from notochordal rem- more remote points, for example over the lateral nants in the basisphenoid or basioccipital bone, aspect of the cerebrum, does not nullify this may resemble (2)macroscopically. Microscopic- theory since Schmidt (1902) demonstrated isolated ally such tumours are composed of alveolar masses nests of arachnoid cells within the dura remote of large ' physaliphorous' cells of characteristic from the sinuses. These nests increase in fre- foamy appearance due to the presence of mucin quency with age. Study of the spinal meningio- (Fig. i), which is also present to a variable extent mata and of certain intraventricular tumours in the stroma. Glycogen has also been demon- arising from the stroma of the choroid plexuses on September 30, 2021 by guest. strated in the cells (see also Burrow and Stewart, shows that the pial and arachnoid membranes may 1923-24). also, though more rarely, be the site of origin of Cholesteatoma, solitary plasmacytoma and these tumours- cavernous angioma are all very rare tumours of the The meningioma typically is a firm, ovoid or diploe. bun-shaped mass with an encapsulated, irregularly lobulatednor smooth surface traversed by many 2. Meninges small veins and capillaries (Fig. 2). Tumours I. Meningioma (syn.: dural endothelioma, arach- arising from the falx or tentorium may be of noidfibroblastoma, meningealfibroblastoma). These dumb-bell shape owing to their growih from *are benign, circumscribed tumours usually arising either side of the dura. Less, frequently the from and firmly attached to the dura, and em- tumour forms a thin layer on the inner surface of bedded in but seldom invading the brain. They the dura (pmeningioma-en-plaque') or, more constitute 14 per cent. of all primary intracranial rarely is villous The surfaces are usually March 1950 RUSSELL: The Pathology of Intracranial Tumours III Postgrad Med J: first published as 10.1136/pgmj.26.293.109 on 1 March 1950. Downloaded from 1t1 Protected by copyright. FIG. 3.- Meningioma invading bone. H. & E. x 80. FIG. 4.Meningioma. H. & i:. x I9. 'pinkish-red or grey and when cut are tough and The microscopical appearances of these tumours fibrous, *with* a * grained. appearance. 1% either of vary considerably. Bailey and Bucy ^('93') whorled character or of streaks radiating fan-wise recognized nine types. Analysis of IO4 surgical from the dural attachment. The haemangio- specimens at the London Hospital has led to their matous variety appears highly vascular ; the subdivision into the following groups, arranged in xanthomatous is distinguished by opaque ochreous order of frequency :-(i) endotheliomatous, 56.6 areas, especially beneath the capsule. The skull per cent., (ii) fibroblastic, 29.2 per cent., (iii) at the site of dural attachment often shows a angioblastic, 7.5 per cent., (iv) xanthomatous, diffuse thickening or ' hyperostosis.' Both tables 3.8 per cent., (v) myxomatous, 2.8 per cent. Full http://pmj.bmj.com/ may bulge, or the inner table only may show a histological details are published elsewhere (Bland conical projection. Cushing (1922a) estimates and Russell, I938), but the following summaries that hyperostoses occur in about 25 per cent. of provide the main points. all meningiomas. It has usually been assumed (i) Endotheliomatous. Alveolar masses or sheets that this change is accompanied by an invasion of of large polygonal cells often with indefinite the medullary spaces by tumour. Where the bony borders. Whorls and psammoma bodies often thickening is great, as in meningioma-en-plaque, present, sometimes abundant. Fibroglia fibrils on September 30, 2021 by guest. SUChl invasion iS microscopically COIlSpiCUOUS absent. Reticulin fibres confined to vessels and (Fig. 3) and may even extend into the temporal trabeculae. Many, transitions between (i) and muscle. But where t'he thickening is slight and (ii) (Fig. 4). confined to the inner table the medullary spaces (ii) Fibroblastic. Interlacing bundles of long often show merely enlargement and fibrosis. spindle cells containing fibroglia fibrils. Coarse Thickening and invasion of the bone by tumour reticulin and collagen fibres often present. Whorls is frequent in the basal meningiomata. It has and psammoma bodies scarcer than in (i). been noted in five of eight examples occurring (iii) Angioblastic. Rich network of capillary in the anterior fossa at the London Hospital, an spaces lined with plump endothelial cells. Similar observation which suggests that direct trauma cells filling tissue between capillaries. Abundant plays little part itn the production of this bony reticulin but no fibroglia fibrils present. Inter- change, although it seems likely that trauma is an stitial cells may be xanthomatous. aetiologic'al factor in the production of men- (iv) Xanthomatous. Like (i) but cells in many ingiomas as a class (Cushing, 1922b). areas filled with anisotropic lipoid. I 12 POSTGRADUATE MEDICAL JOURNAI, March i95o Postgrad Med J: first published as 10.1136/pgmj.26.293.109 on 1 March 1950. Downloaded from (v) MWyxomatous. Spindle and stellate cells un- is a rare congenital condition associated with evenly distributed in a stroma giving reactions for pigmented naevi in the skin, and is one of the mucin, and rich in reticulin fibrils. Fibroglial many causes of congenital hydrocephalus. The fibrils absent. areas affected show a diffuse discoloration varying Examples of (i) or (ii) may, exceptionally, be of from cafe-au-lait to brownish-black. Micro- a melanotic character. Others in these two groups scopically the leptomeninges are infiltrated with occasionally form lamellar bone ; such are more pigmented naevoid cells which infiltrate the likely to occur in the spinal canal than within the adjacent nervous tissue along the sheaths of the cranium. perforating vessels (see review of published cases Apart from the tendency towards excessive by Schnitker and Ayer, I938). haemorrhage during operative removal in group 4. Lipoma. These rare tumours, arising in de- (iii) this histological subdivision does not appear velopmental rests, may be found in the mid-line to be of much clinical significance. A detailed over the corpus callosum, tuber cinereum or mid- account of the meningiomas has been published brain. Although sometimes deeply embedded in by Cushing and Eisenhardt (1938). the brain their pial connection is always retained. 2. Sarcoma. Circumscribed and diffuse prim- They rarely cause symptoms (Ewing, I922). A ary sarcomata of the meninges have been de- review of the literature with an account of a case scribed; they are exceedingly rare. It must be showing extensive lipomatosis of the meninges remembered that the term ' sarcomatosis ' was often has been published by Baker and Adams (1938). used in the older literature for a condition in which .