This form of tumour is of somewhat frequent occurrence, and we may have round-celled or spindle-celled growths, which sometimes assume considerable dimensions. Sarcomas sometimes originate from soft warts or moles, and when they do so they frequently present a similar structure to that described above, namely, masses of large round cells in a stroma. To this form the name Alveolar sarcoma is applicable. Sarcomas originating from moles are peculiarly apt to be pigmented.

Sarcomas rarely occur as secondary tumours in the skin, but a case is known to the author where multiple tumours composed of round-celled tissue formed at intervals, in the subcutaneous tissue, and some of them disappeared. These were either round -celled sarcomas or malignant lymphomas.