Sarcoma and Melanoma of the Rectum

SARCOMA and melanoma are relatively rare forms of malignant disease in the rectum.At St. Mark's Hospital we have met with only eight cases of sarcoma and two of melanoma during the last 18 years (1929 to 1946 inclusive), whereas during this period we examined more than 2,200 operation specimens of rectal carcinoma.Judged from this experience sarcoma and melanoma constitute approximately 0.5 per cent of malignant rectal tumours.This agrees fairly closely with the estimates of other observers (Weeks, 1927; Sutton, 1932; Kallet and Saltzstein, 1932; McSwain and Beal, 1944).As we met with these tumours one by one at infrequent intervals we noticed that they varied considerably in their histology, but now that we have collected and reviewed a small series of cases it is clear that they fall naturally into four groups, namely lymphosarcoma, reticulum cell sarcoma, spindle cell sarcoma and melanoma.It will save repetition if before describing our cases we mention the chief points in the histology of each of these groups. HISTOLOGY OF TUMOURS.We acknowledge with gratitude the receipt of a grant from the British Empire Cancer Campaign towards the expenses of this research.