Malignant testicular tumors appearing simultaneously in identical twins.A case report

T tation provides a unique opportunity for studying the importance of inheritance upon disease.Study of concordance rates of tumors among populations of twins has failed to establish a precise role of inheritance in the risk of falling victim to cancer in general; however, more detailed knowledge of individual types of tumors with relation to genetic background is needed to answer the question with authority.Reports of concordance and discordance of cancer in twins should continue in order that specific cases will be recorded for subsequent review.T h e following report describes the fifth recorded twin set concordant for testicular cancer, the third said to be identical, and the first whose monozygosity is supported by detailed blood group determinations.Of special note is the strikingly coincident onset of the tumors. CASE REPORTA 37-year-old Caucasian farmer was admitted to the Palo Alto-Stanford Hospital April 15, 1964 for consideration of further treatment one week following excision of the left testis and spermatic cord for a testicular tumor consisting of teratoma and embryonal