Editorial: Acute dermal gangrene.

Abstract

BRITISH MEDICAL JOURNAL 13 SEPTEMBER 1975 607 areas with a high incidence of choriocarcinoma are also those areas where hydatidiform mole is frequent, and since mole pregnancies give rise to choriocarcinoma about 1000 times more often than non-mole pregnancies1 4 5 there is a possibility that the geographical distribution of choriocarcinoma might be determined largely by that of hydatidiform mole. Though the multicentre report3 suggested that the frequency of moles was not the sole factor, data indicating the relative importance ofterm deliveries, hydatidiform moles, and non-mole abortions as the antecedent and causal pregnancy are woefully inadequate for most countries. A wide variety of factors which might play a part in the causation of either hydatidiform mole or choriocarcinoma or both of these conditions have been considered, for there are few strong leads. A viral cause has been proposed.6 Malnutrition was thought to play a part in the Philippines7 and has been considered in W. Africa,2 but in Hawaii8 it was found to be uncommon in the poorest population. In Singapore a valuable study9 showed that choriocarcinoma is more common in Indians and Eurasians than in Chinese and Malays, whereas in Hawaii8 it is more common in Chinese than in Caucasians and Polynesians. Birth order appears to play no part, but both lesions are most common' 3 4 9 (in relation to the total number of pregnancies) under 20 years and over the age of 40. The tendency for childbearing to continue late in reproductive life in the high-incidence countries undoubtedly accounts for some but not all of the excess cases.Placental choriocarcinoma is a tumour of the fetus which invades maternal tissue, and consanguinity has been suspected as a cause,'0 but such evidence as exists is anecdotal. The possibility that the tumour arises only when there is a high degree of immunological similarity between the patient and her fetus has been excluded by extensive studies of the HL-A factors in affected families in Britain"1 and U.S.A.12 There is evidence, however, that the ABO blood groups of the patient and her male partner are important aetiological factors in the development of choriocarcinoma but not hydatidiform mole.'3 For instance, a group A woman has a high risk of getting choriocarcinoma if her husband is group 0 but low risk if he is group A. Moreover, the blood groups of the patient and her husband affect prognosis.'4 There is a real difference in the distribution of ABO blood groups between the high and low incidence areas of the world'5 and there may be similar differences for other genetic factors. How much the ABO groups and other genetic factors influence the geographical distribution of choriocarcinoma remains to be explored. Conceivably they might act directly or by altering susceptibility to carcinogenic agents. Acute Dermal GangreneMeleney's spreading gangrene is one of those apparently familiar clinical syndromes which are rarely seen. It was described' in 1924 and the gangrene of the skin was attributed to a synergistic inf...