Iodamoeba butschlii in a routine cervical smear

Dear Editor, Iodamoeba butschlii is a non pathogenic intestinal amoeba of humans and pigs. It is common in swine, which might have been the original host. It has a worldwide distribution and is occasionally encountered in clinical specimens. Like other intestinal amoebae, it is transmitted by cysts. In most stool surveys it occurs in 2–6% of adults. While trichomonads are common in cervical smears, observations of amoebae in the female genital tract are relatively uncommon. The majority of cases reported have been of Entamoeba histolytica. Entamoeba gingivalis has rarely been found in patients having intrauterine contraceptive devices and colonized by actinomyces. Accurate classification of amoebic trophozoites is difficult in cervical smears. Here we present the interesting finding of I. butschlii in a routine Papanicolaou-stained cervical smear, which has not been reported previously. A 35-yearold woman presented to the gynaecology clinic for a routine check up. The patient s physical examination and past medical history were unremarkable. A routine cervical smear showed a background of intermediate and superficial cells with mild inflammation. Many trophozoites were seen measuring 8–25 lm in size, ovoid in shape (Figure 1) along with cysts. The trophozoites had dense-staining central endoplasm and lighter staining peripheral ectoplasm, which formed pseudopodia. Ingested food and nuclear fragments were present in the cytoplasm (Figure 2a–c). The nucleus had a smoothly rounded central karyosome, surrounded by a vesicular space and well-defined nuclear margin (Figure 2a,b). The cysts varied from 5 to 20 lm in size, being slightly smaller than the trophozoites (Figure 2b) and were round to oval with a single nucleus situated at one pole. The nuclear details were blurred. The most striking feature of the cyst was a large, sharply defined glycogen vacuole (Figure 2d). Direct faecal contamination appears to be the most likely explanation for presence of the parasite in this smear, although the parasite was seen in profusion, intricately admixed with the epithelial cells and without any identifiable faecal material being seen on the slide. Stool examination and a follow-up cervical smear did not identify the organism. Protozoal parasites previously reported in cervical smear cytology include Trichomonas vaginalis, E. histolytica, E. gingivalis and Toxoplasma gondii. Fine nuclear and cytological details of the Trophozoites and cysts of I. butchlii are helpful in diagnosis. Iodamoeba differ from the commonly seen trichomonads in their shape, nuclear morphology, presence of two cytoplasmic zones with pseudopodia, ingested cytoplasmic debris and the presence of cysts. Entamoeba histolytica trophozoites have a small central karyosome and the cytoplasm may show phagocyFigure 1. Cervical smear showing a superficial cell and three trophozoites of Iodamoeba butschlii, which have a round to oval shape. Nucleus is centrally placed with a prominent central karyosome surrounded by a clear vesicular space and a sharp nuclear margin. Papanicolaou stain, ·400.