Fig. 141.—Multiple Cartilaginous Exostoses in a man æt. 27, the same as in [Fig. 140].
Diffuse Osteoma, Leontiasis Ossea.—This rare affection was described by Virchow, and named leontiasis ossea because of the disfigurement to which it gives rise. It usually commences in adolescence as a diffuse overgrowth first of one and then of both maxillæ; these bones are enlarged in all directions and project on the face, and the nasal fossæ and the maxillary and frontal sinuses become filled up with bone, which encroaches also on the orbital cavities. In addition to the hideous deformity, the patient suffers from blocking of the nose, loss of smell, and protrusion of the eyes, sometimes followed by loss of sight. The condition is liable to spread to the zygomatic and frontal bones, the vault of the skull, and to the mandible. The base of the skull is not affected. The disease is of slow progress and may become arrested; life may be prolonged for many years, or may be terminated by brain complications or by intercurrent affections. In certain cases it is possible to remove some of the more disfiguring of the bony masses.
A less aggressive form, confined to the maxilla on one side, is sometimes met with, and, in a case of this variety under our own observation, the disfigurement, which was the only subject of complaint, was removed, after reflecting the soft parts, by paring away the excess of bone; this is easily done as the bone is spongy, and at an early stage, imperfectly calcified.
A remarkable form of unilateral hypertrophy and diffuse osteoma of the skull, following the distribution of the fifth nerve, has seen described by Jonathan Hutchinson and Alexis Thomson.
Chondroma.—Cartilaginous tumours, apart from those giving rise to multiple exostoses, grow from the long bones and from the scapula, ilium, ribs, or jaws. They usually project from the surface of the bone, and may attain an enormous size; sometimes they grow in the interior of a bone, the so-called enchondroma.
Fig. 142.—Multiple Chondromas of Phalanges and Metacarpals in a boy æt. 10 (cf. [Fig. 143]).
The hyaline cartilage composing the tumour frequently undergoes myxomatous degeneration, resulting in the formation of a glairy, semi-fluid jelly, and if this change takes place throughout the tumour it comes to resemble a cyst. On the other hand, the cartilage may undergo calcification or ossification. The most important transition of all is that into sarcoma, the so-called malignant chondroma or chondro-sarcoma, which is associated with rapid increase in size, and parts of the tumour may be carried off in the blood-stream and give rise to secondary growths, especially in the lungs.