Pentastomiasis and cancer of the colon

Abstract

The case is described of a 50-year-old man, admitted to a small mission hospital in Zaire, where a preliminary diagnosis of cancer was made. On referral to a bigger hospital he was found to be infected with Entamoeba histolytica and biopsy of the peritoneal tumour revealed a pentastomid nymph, probably of Armillifer armillatus, the most common pentastomid infecting man in Zaire. X-ray subsequently revealed numerous calcified nymphs. Surgical and anti-parasitic treatment are described and the possible association between pentastomid infection and cancer is discussed. As Self, Hopps & Williams (1975) admit, our knowledge of pentastomiasis in Africa is incomplete and it must be assumed that its occurrence is much more widespread than published reports indicate. It may, therefore, exist throughout much of sub-Saharan Africa, as does liver cancer. Nymphal pentastomiasis in man caused by Armillifer armillatus is generally discovered during surgical intervention or at necropsy. Pathological complications caused by the nymphs are very rare. However, Fain (1975) has drawn attention to the possibility of a carcinogenic action of pentastomids and, although the arguments for this association may be weak, it is an interesting hypothesis bearing in mind the association between clonorchiasis and cancer of the bile-ducts and schistosomiasis and cancer of the urinary bladder. We describe below a case of cancer of the colon accompanied by pentastomiasis.