ions of the bone and from lesions of the adjacent
joint.

[Illustration: FIG. 152.--Radiogram of Chondro-Sarcoma of Upper End of
Humerus in a woman aet. 29.]

Skiagraphy is not only of assistance in differentiating new growths from
other diseases of bone, but may also yield information as to the
situation and nature of the tumour, which may have important bearings on
its treatment by operation.

When fracture of a long bone takes place in an adolescent or young adult
from comparatively slight violence, disease of the bone should be
suspected and an X-ray examination made.

In difficult cases the final appeal is to exploratory incision and
microscopical examination of a portion of the tumour; this should be
done when the major operation has been arranged for, the surgeon waiting
until the examination is completed.

The _prognosis_ varies widely. In general, it may be said that
periosteal tumours are less favourable than central ones, because they
are more liable to give rise to metastases. Permanent cures are
unfortunately the exception.

_Treatment._--When one of the bones of a limb is involved, the usual
practice has been to perform amputation well above the growth, and this
may still be recommended as a routine procedure. There are reasons,
however, which may be urged against its continuance. High amputation is
unnecessary in the more benign sarcomas, and in the more malignant forms
is usually unavailing to prevent a fatal issue either from local
recurrence or from metastases in the lungs or elsewhere. Following
the lead of Mikulicz, a considerable number of permanent cures have been
obtained by resecting the portion of bone which is the seat of the
tumour, and substituting for it a corresponding portion from the tibia
or fibula of the other limb. In a cellular sarcoma of the humerus of a
boy we resected the shaft and inserted his fibula ten years ago, and he
shows no sign of recurrence. When resection is impracticable, a
subcapsular enucleation is performed, followed by the insertion of
radium.

#Pulsating Haematoma# or #Aneurysm of Bone#.--A limited number of these
are innocent cavernous tumours dating from a congenital angioma. The
majority would appear to be the result of changes in a sarcoma,
endothelioma, or myeloma. The tumour tissue largely disappears, while
the vessels and vascular spaces undergo a remarkable development. The
tumour may come to be represented by one large blood-containing space
comm