[In situ adenocarcinoma of the uterus cervix: difficulties of its cytohistological diagnosis].

In situ adenocarcinoma is regarded as the precursor of invasive adenocarcinoma. It is asymptomatic and early diagnosis relies solely on cytopathologist. It is usually discovered on a cone for squamous CIN. When diagnosis is made by biopsy, conisation is required to exclude invasive adenocarcinoma. Lesion is histologically characterised by epitheliomatous transformation of endocervical glands without invasion of the chorion. By the appearance of glandular cells, different histological varieties are described. They have no influence on the prognosis. Several benign lesions may mimic adenocarcinoma: tubal metaplasia, glandular atypia due to inflammation or irradiation, mesonephric remnants and microglandular hyperplasia. Precursor lesions (atypical hyperplasia, glandular dysplasia, CIGNI and II) are badly morphologically defined. Preferential location of in situ adenocarcinoma is the transformation zone. Because of this topography, if the surgical margins are disease free, conisation alone may be adequate therapy. HPV infection (mainly HPV 18) are incriminated in its pathogenesis.