Ordinarily it is not profitable to use single atypical cases for deductions of general nature. However, once in a while, a freak case illuminates a confused and debated field just because it presents singular and ruledefying features.
A case of this kind, in the experience of one of us (H.P.), was the man who had a mucin-producing adenocarcinoma of the rectum in the usual location, 8 cm from the anus, which had metastasized widely in the body. It also was associated with clinically typical Paget's disease of the perianal skin, much in the fashion in which the skin around a carcinomatous milk duct becomes affected in the mammary form of Paget's dermatosis. Mucin-bearing cells, resembling Paget cells, were present in the anal and perianal epidermis1 and were thought to have originated in the rectal carcinoma as suggested earlier by Muir2 and others.
The case lent support to the