The occurrence of an epithelial cyst enclosed within the bony structure of a phalanx of a finger is a rare condition, for such a case has not been reported in the medical literature of this country. Neither can it be found mentioned in the recent textbooks of general and orthopedic surgery, of tumors and also of bone diseases. So to present a case in which it was found should be of interest. An explanation of its origin embraces two possibilities: first, that of congenital malformation with inclusion of aberrant epithelial cells, comparable to the formation of a simple dermoid cyst; second, that of traumatic implantation.
Five cases have been found recorded in the European medical literature; this presentation makes a sixth case, the first in America.The first recorded was one by Sonntag1 in 1923: A young female injured the left hand in a machine, crushing the
Yachnin SC, Summerill F. TRAUMATIC IMPLANTATION OF EPITHELIAL CYST IN A PHALANX. JAMA. 1941;116(12):1215-1218. doi:10.1001/jama.1941.62820120001008