Background: The association between Schistosoma haematobium and cervical cancer has been reported for a long time. However, recently human papillomavirus, a cofactor in the genesis of cervical cancer, has been confirmed. A case of squamous intraepithelial lesion after S haematobium infection is presented, and the relation between schistosomiasis, human papillomavirus and squamous intraepithelial lesion, with long-term follow-up by Papanicolaou smear, is discussed.
Case: A 33-year-old, normal, healthy woman with a history of Copper intrauterine device (IUD) use for 3.9 years presented for her annual contraceptive follow-up. Her Pap smear revealed inflammation with a S haematobium egg. She was followed up with Pap smears for 4 years. Retrospective contraceptive history revealed use ofa copper IUD on 5 occasions with a total duration of 13 years and 1 month. Similarly, annual follow-up of Pap smears for the past 13 years showed mild inflammation with bacterial vaginitis and monilial infection. Subsequent smears showed an Actinomyces-like organism and then human papillomavirus infection with atypical squamous cells of undetermined significance followed by human papillomavirus-associated low/high grade squamous intraepithelial lesion.
Conclusion: Caution is required while screening routine Pap smears. Apart from nuclear abnormalities, one can observe unusual findings. Long-term followup by Pap smear following detection of S haematobium revealed that in the absence of human papillomavirus, S haematobium alone is not the causative agent for the abnormal proliferation of squamous epithelium of the cervix. Genital Schistosomia acts as a cofactor by traumatizing the genital epithelium or immune suppression to favor human papillomavirus infection.