Page:Archives of dermatology, vol 6.djvu/213

Rh since the pigmentation lies in the protoplasm. The intensity of pigmentation varied throughout the tumor.

The third case, from a man aged 42 years, was upon the volar aspect of the right wrist. Fifteen years before, and without known cause, it appeared, and remained unchanged for eight years, then for five years it increased in size and became painful. During the last two years it acquired half again the size of a silver dollar, and the administration of four subcutaneous injections of morphine per diem was needed on account of the very severe pain. Large veins covered the tumor, swelling on compression with pain, but becoming smaller, as did also the whole tumor, when the hand was suspended in a sling. It was excised. Microscopically, the tumor was composed essentially of structureless or fibrillary stroma, in which were embedded numerous vessels and variously-shaped groups of small round cells, with a large nucleus and a thin, bright border of protoplasm. Towards the periphery this stroma was opaque, fibrillar, and rich in connective-tissue cells; towards the centre the fibrils and cells became less frequent, the tumor more transparent, and took on the mucous-like condition of a myxoma (angiosarcoma myxomatosum). Veins preponderated over arteries in this tumor, and the pain appeared to arise from compression of nervous filaments. The walls of the abundantly new-formed vessels underwent also in many cases mucous or hyaline change. Melanosis of both stroma and cells existed. Sarcoma cells lined the walls of the vessels, and it is the intercellular substance of the external layers of these cells which, according to Maurer, become affected by the hyaline degeneration which takes its origin in the stroma between the vessels. Arndt (Virch. Arch., Bd. 41, p. 461) holds that it is the cells themselves which swell.—''Virch. Arch.'', Bd. 77, p. 346.