[Read before the Philadelphia Academy of Surgery, November 6, 1893.] 
TUMORS OF THE PERIPHERAL NERVES; WITH 
THE REPORT OF A CASE OF SARCOMA 
OF THE SCIATIC. 
By THOMAS S. K. MORTON," M.D., 
Professor of Surgery in the Philadelphia Polyclinic. 
All tumors growing in or upon peripheral nerve trunks have 
come to be classed as neuromata, and of these two general divi- 
sions are made-the true and the false. The true neuroma is 
composed of nerve elements, while a false neuroma is a tumor 
developing in connection with a nerve or its sheath, but not com- 
posed of nerve elements. Virchow has proposed that only true 
nerve-tissue growths be called neuroma, while other tumors grow- 
ing in connection with nerves shall receive the same name as would 
similar neoplasms occurring elsewhere. This more simple and 
accurate method of classification has not, however, been followed 
generally by writers. 
Fibroma is the common tumor found in connection with nerve 
trunks, and is usually composed of white fibrous material with few 
connective-tissue cells. Plexiform and multiple neuromata are 
usually congenital and often hereditary, slowly growing varieties 
where a number of nerves undergo a fibrinous change and occa- 
sionally form plexes of sensitive interlacing cords. The subcu- 
taneous terminal extremities of sensory nerves may undergo fibrous 
changes and form the so-called "tubercle dolorosa." According 
to Bowlby1 sarcoma is next in order of frequency. " They may 
belong to the round, oval, or spindle-celled-varieties. In such 
growths, especially in those which increase most rapidly in size, 
degeneration cysts may form so that the tumor may become partly 
filled with fluid. The contents of such cysts are usually blood and 
broken-down cells." Very rarely myxomas are met with. In 
these the mucoid material grows from the nerve sheath. Glioma, 
as may also be said of syphiloma, is all but unknown excepting 
upon the cranial nerves, and even upon these is almost never 
observed beyond the confines of the cranium. Two cases of simple 
1 Injuries and Diseases of Nerves. London, 1892. 2 
cyst containing clear fluid, in connection with nerve trunks, have 
been recorded by Bowlby. I have found references to cases upon 
record as flbro-sarcoma, myxo-sarcoma, and cavernous sarcoma, 
also to "blood-cyst" of nerve trunks-the two latter, in the light 
of modern pathology, probably being instances of cystic degenera- 
tion of simple sarcoma. All nerve tumors show a marked ten- 
dency to malignant degeneration. Secondary or metastatic tumors 
of nerves are probably not uncommon. Probably more records of 
tumor of the optic nerve than all others put together are to be 
found in medical literature, but nerve-trunk tumors must be con- 
sidered as rarities when judged by the very small number that I 
have been able to find reference to in the books and Index Medicus. 
Diagnosis before operation, except in the case of superficial 
neuromata, unless there are marked motor or sensory disturbances, 
is almost impossible in the majority of cases. Even these symp- 
toms may be simulated by pressure upon the nerve by outside 
growths. It is a remarkable fact that most tumors of nerves give 
rise to but trivial changes of sensation, and the conveying and 
trophic power of the fibres is almost never fully destroyed. When 
the tumor has actually been exposed by dissection, unless the sur- 
geon is exceedingly careful, a nerve is liable to division or other 
injury before the true nature of the growth is discovered. Cases 
are upon record where excellent surgeons have not recognized the 
nature of tumors until the ensuing paralysis of function and the 
microscope have solved the problem. 
Removal of those neoplasms which involve all of the bundles 
necessitates total division of the nerve trunk above and below the 
tumor; which should be followed, if possible, by immediate ap- 
proximation of the ends by the employment of some one of the 
various methods of suturing, lengthening, or splicing, and the sub- 
sequent placing of the parts by posture in that position which gives 
greatest relaxation to the nerve trunk involved. Where approxi- 
mation is impracticable the ends should be "aimed" at each other 
by chromic catgut sutures, and regeneration with more or less resto- 
ration of function may be expected to slowly supervene in many 
cases. When the growth involves simply the sheath of a nerve, 
either internally or externally, prompt recognition of its nature and 
relations, together with careful dissection, will prevent injury to the 
nerve itself. If the tumor is within the sheath-as in my case- 
a longitudinal division of the sheath without division of any of 
the nerve fibres will be sufficient to fully expose it. If then it is 
found to arise from a few of the nerve bundles these may be 
divided and the growth shelled out of its bed, if possible, without 
rupturing the capsule if it possess one. Any small number of 
fibres that may be thus divided may be expected to regenerate and 
coalesce; larger bundles should at once be sutured with catgut. 3 
Subsequent suture of the divided sheath would appear to be a neat 
point of technique, but, as proved in the case here reported, is 
sometimes unnecessary. On the other hand, the possibility of hem- 
orrhage taking place within a tightly sutured sheath must not be 
lost sight of. Gowers is authority for the statement that excision of 
nerves on account of tumor is prone to be followed by the develop- 
ment of bulbar (traumatic) neuromata. This may have been true 
of nerve sections prior to the antiseptic period, but absence of sup- 
puration, combined, as it often can be, with immediate suture 
should render such results here, as elsewhere, very unusual. 
The history of the case which has suggested these remarks is as 
follows : 
Airs. D. A., aged forty-two years, a Russian of the middle class, 
entered the Polyclinic Hospital October 3, 1893, with a tumor 
upon the back of the left thigh. Family history negative so far 
as could be secured. Physical examination, excepting the tumor, 
negative. Urine normal. 
She stated that about one year previously she had accidentally 
discovered a small nodule deeply situated upon the posterior por- 
tion of the left thigh ; that it had grown slowly at first, but during 
the past three months with increasing rapidity; and that, except- 
ing inconvenience in sitting upon the mass, which gave rise to some 
pain, the tumor had caused little or no discomfort. No definite 
history of any sensory or motor disturbance in the sciatic distribu- 
tion could be elicited. 
The growth was the shape and size of a large goose-egg, with its 
long axis corresponding to that of the thigh. It lay exactly over 
the course of the great sciatic nerve, midway between the tuberosity 
of the ischium and the flexure of the knee-joint. It could be 
moved somewhat from side to side, but almost none at all upward 
or downward. It did not move when the posterior muscles of the 
thigh were exerted. To pressure and palpation the growth was 
almost insensitive. It felt like a soft fibroma or fibro-lipoma but 
did not impart any sense of fluctuation. 
On October 6th a careful dissection was made and the tumor 
exposed at the base of a six-inch incision. It was noted that each 
time the growth was impinged upon by the finger or an instrument 
the lower leg gave a sharp, convulsive start. When moderately 
cleared of its surroundings the fact that a neoplasm involving the 
sciatic nerve was to be dealt with was made very evident by obser- 
vation that the fibres of that nerve could be seen as glistening 
white cords of varying size beautifully frayed or spread out as 
they ran around the growth through the encapsulating nerve 
sheath. A vertical incision, avoiding nerve fibres, was made to 
the full extent of the tumefaction through this apparent capsule, 
when it was further discovered that the tumor proper was entirely 4 
disconnected with the sheath, and was separately enclosed in a 
capsule within. The growth was readily separated from the sheath 
of the nerve in all directions except at points at the extreme prox- 
imal and distal extremities, where a few nerve fibres entered and 
emerged from it respectively. Some small bloodvessels appeared 
to accompany the strands of nerve substance into the tumor. 
These fibres having been divided, the growth was lifted out with- 
out further difficulty. Upon examining the cavity in the nerve 
sheath from which it came it was observed that most of the bundles 
of the sciatic were in advance of and had been spread out over the 
external surface of the growth, but that no appreciable injury had 
been done them with the exception of the few fibres which had 
necessarily been divided as they entered the tumor. No sutures 
were applied to the nerve sheath nor were any ligatures called for. 
The wound was closed without drainage by alternate deep and 
superficial silk sutures and a pad of dressing so applied as to make 
compression upon the cavity left by the tumor. The operation 
was followed for two days by some pain in the whole sciatic dis- 
tribution, but especially in the region supplied by the external 
popliteal, but no loss of power ensued. All pain disappeared in 
forty-eight hours, however, and afterward she had no disagreeable 
sensations. Upon the seventh day all sutures were removed and 
absolute primary union throughout was found. On the tenth day 
she began to walk about, and four days later walked home, appa- 
rently as well as ever. Up to this date she has so continued. 
The tumor was ovoid in shape, four inches in length and seven 
in circumference where thickest. At either extremity a few nerve 
fibres and bloodvessels appeared to enter or take their exit. Other- 
wise there were neither adhesions nor pedicle. The growth was 
encapsulated with a tough brownish-colored membrane which 
brought away small granular portions of the tumor when forcibly 
separated from it by peeling. The neoplasm proper was of a 
yellowish-brown color, rather dry, and cut like fibro-fatty tissue. 
Exactly in the centre of the mass was a cavity, not definitely sepa- 
rated from the growth, which contained about half an ounce of 
bloody fluid. Most unfortunately, during the preparation of the 
specimen for further study it was accidentally destroyed, so that I 
have not the satisfaction of adding to my clinical and gross patho- 
logical diagnosis of sarcoma that of microscopical confirmation. 
However, the details of several cases almost identical with this in 
every way, which I append, where sarcoma was proved by the only 
accurate method, will, I trust, be found to justify me in classing 
this case as one of that dread malady. 
From the scant literature of peripheral nerve tumors I have 
abstracted the following cases, which are of great additional in- 
terest from the evidence which some of them afford relative to the 5 
remarkable regenerative powers of nerves, even when great lengths 
have been removed with tumors and suture has been omitted or 
found impossible. 
Hume1 reports the ease of a man, aged twenty-four, who pre- 
sented himself with a tumor on the back of the left thigh, which 
he had observed for five months. It extended from the fold of the 
buttock to the upper part of the ham, being ovoid in shape and 
movable from side to side, but not from above downward. There 
was much pain in the knee and foot, but no loss of motion or sen- 
sation. The tumor was easily shelled out with division of the 
entire nerve above and below. The growth was surrounded by 
and incorporated with the strands of the nerve. Besides the main 
portion of the tumor, the nerve trunk above and below appeared 
to be infiltrated with the same material, so that it was necessary to 
remove in all six inches of the sciatic. The cut surface of the 
growth was of a yellow fatty appearance. There were several 
hemorrhagic spots in its substance; also others that looked like 
necrotic or caseating patches. It proved to be sarcoma. The man, 
soon after operation, was able to walk upon the limb, but there was 
much wasting and great impairment of sensation. Below the 
knee palsy of muscles and sensation was complete six months 
after operation. 
A second case, recorded in the same place by Hume, was that of 
a man, thirty-seven, who had noticed a nodule under the gluteus 
maximus of the left side four months before coming under obser- 
vation. He had been subject to molluscum fibrosum from child- 
hood. At the time of operation the growth had attained the 
size of a " melon." It was found to originate in the great sciatic, 
the strands of the nerve being stretched over and incorporated with 
the capsule of the tumor. The small sciatic lay over the tumor 
and was pushed aside. To remove the growth it was necessary to 
entirely divide the nerve close to the sciatic notch above and at the 
border of the gluteus below. By stretching of the nerve ends and 
extreme flexion of the knee and extension of the hip, all of the 
upper end of the nerve and one-half of the lower extremity were 
brought together and sutured with strong catgut. In order to 
lessen strain upon the sutures the patient was made to assume the 
prone posture with the hip in extreme extension. The tumor was 
found to be a round-celled sarcoma. There was primary complete 
paralysis of the functions of the sciatic. Eighteen months later 
skin sensibility of the foot was absent, but that above the ankle 
was almost normal, and there was very little atrophy of the muscles. 
At this time he presented a large sarcoma of the right chest wall, 
with pleural effusion, and died five months subsequently. It was 
1 Lancet, September 19,1891, p. 654. 6 
then found that he also had a growth in connection with the pleura; 
nodules in several of the intercostal nerves, the liver, and in the 
humerus and lung of the opposite side. At the site of operation 
the sciatic nerve was found at the level of the tuberosity of the 
ischium to be divided into two portions; the internal of these 
passed into a nodular swelling, which was continuous upward with 
the proximal portion of the nerve; the external portion was lost 
in cicatricial tissue, by which it was attached to the surrounding 
parts and to the side of the nodule. The whole thickness of the 
lower end of the central portion was continuous with the nodular 
swelling. The latter had evidently formed at the line of suture 
with that portion of the peripheral division of the nerve which it 
had been possible to bring into contact at the operation. The 
nodule consisted entirely of nerve tubules and fibrous tissue. There 
was no local recurrence of sarcoma. 
Hume, in the same article, also records the following ease : A 
man, aged forty, had recognized a rapidly growing nodule behind 
his knee for four months. Upon incision a large oval growth of 
great vascularity was found in connection with the internal pop- 
liteal nerve. The short saphenous nerve was stretched over it, thus 
explaining all pain that the patient had suffered. Three and a half 
inches of the nerve were excised. The ends were not sutured. 
The man soon returned to his occupation of miner, with paralysis 
of the popliteal distribution. The growth was encapsulated in the 
sheath of the nerve and appeared to be defined at each end, but a 
small number of nerve fibres passed through it. The bulk of the 
substance of the nerve laid behind the tumor. In its interior one 
or two cavities filled with blood were found. Six years subse- 
quently the cutaneous sensibility of the leg had returned to the 
normal, excepting a slight impairment in the centre of the sole, 
and all muscular movements of the leg and toes were perfect. 
There was no wasting of the parts whatever. 
Little1 reports the following case : A woman, aged twenty-five, 
presented a large, firm tumor upon the posterior portion of the 
thigh above the popliteal space. The first symptoms were dull 
pains along the thigh and upward. There was no pain in walking, 
but considerable discomfort in sitting. The tumor pedicle sprang 
from the sciatic nerve sheath. One inch of the nerve was resected 
and the ends sutured together. The functional result was almost 
perfect in a few months. The growth was twelve inches in cir- 
cumference. It proved to be a sarcoma, and probably originated 
from the neuroglia. There was a true bony centre in the tumor. 
McBurney2 records a case where a man, aged twenty-seven, pre- 
1 Boston Med. and Surg. Journ., December 3, 1885, p. 533. 
2 New York Med. Journ., May 1, 1886, p. 504. 7 
sented a growth of six years' development upon the inner side of 
the right arm. There had been no considerable pain until a month 
before operation ; the pain extended down the arm, and pressure 
was exceedingly painful. It was found to spring from the median 
nerve in the upper third of the arm ; was encapsulated, and, when 
opened, it was seen that the fibres of the nerve spread over the 
growth. The major portion of the tumor was behind the nerve. 
The neoplasm and capsule were removed with division of but a 
few fibres of the nerve which entered it. Microscopic examina- 
tion proved the tumor to be fi bro-sarcoma. 
In addition to the above detailed cases I have been able to find 
the following references to sarcoma of nerve trunks ; 
Ramoneda: Sarcoma fuso-cellular del nervio neumogastrico 
derencho; su extirpacion, conservandose la continuidad del tronco 
nervioso; datos interesandes acerca del nervio hipogloso. Rev. 
clin. de 1'hosp. Madrid, 1891, iii., p. 241. 
Van Inschot: Fibro-sarcome caverneux du nerf radial (propag6 
an triceps brachial). Ann. Soc. de MM. de Gand, 1887, Ixvi., 
p. 14. 
Weile: Ein Fall von Sarcom des Nervus radialis. Erlangen, 
1888, 8vo. 
Bardeleben: Sarcom des Nervus ischiadicus. Charite Ann., 
1883, Berlin. " 
Herczel: Ueber Fibrome mid Sarcome der peripheren Nerven. 
Beitr. zur path. Anat. u. z. allg. Path. Jena, 1890, viii., p. 38. 
Peret-Gilbert: Considerations sur les neoplasmes primitifs des 
nerfs des membres. Paris, 1891, 4to. 
Krause: Ueber maligne Neurome und das Vorkommen von Ner- 
venfasern in denselben. Sammi, klin. Vortr., 1887, No. 293.