2.e Aria-Stella Change

Aria-Stella Change

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The Arias-Stella phenomenon is a pregnancy-related change of the glandular epithelium secondary to the simoultaneous effect of estrogens and progesterone. Arias-Stella changes are more frequent in endometrial glands, but can also be seen in endocervical glands. They are characterized by enlarged nuclei with marked atypia, intranuclear inclusions and hobnail architecture. However, the chromatin is smudgy which gives a degenerated appearance to the nuclei. Arias-Stella phenomenon can be confused with clear-cell carcinoma, especially when the pathologist is not aware that the patient is pregnant. Clues that can help exclude a clear cell carcinoma are: absence of a mass or polypoid lesion, presence of other pregnancy-related changes (decidualization), preservation of the normal glandular architecture, degenerated appearance of nuclei and absence of invasion. The presence or absence of mitosis is not a completely reliable feature to distinguish the two entities.