Chlamydia trachomatis is an obligate intracellular parasite which is associated with the formation of granular intracytoplasmic inclusions. It is a common cause of non specific urethritis and cervicitis and accounts for 20% of all cases of pelvic inflammatory disease and infertility.The cytoplasmic inclusions can be seen occasionally in immature metaplastic cells but  cytological diagnosis is unreliable and confirmation by immunofluorescence is essential. Follicular cervicitis may be present.