Arias-Stella reaction

{"favouriteUrl":"/articles/arias-stella-reaction/add_favourite?lang=us","favouriteId":161618,"favouriteKind":"article","loginUrl":"/sessions/new?lang=us\u0026return_to=%2Farticles%2Farias-stella-reaction%3Flang%3Dus","unfavouriteUrl":"/articles/arias-stella-reaction/remove_favourite?lang=us"}

An Arias-Stella reaction is a common gynecological histological finding in curettage specimens of gestational endometrium describing a non-neoplastic lesion that is easily confused with uterine malignancy ^1,2.

Pathology

An Arias-Stella reaction is due to hormonal hyperstimulation causing atypical endometrial glandular cells associated with the presence of viable chorionic tissue ³.

It can present in normal physiologic conditions including pregnancy, postpartum and uterine abortion but is also associated with ectopic pregnancy, gestational trophoblastic disease, and uterine disease affecting the myometrium ¹.

The reaction has also been found in extra-endometrial sites ⁴.

Microscopic appearance

The characteristic features of the Arias-Stella reaction include hypertrophic and hyperchromatic nuclei with abundant cytoplasm and infrequent mitotic activity. The nuclei may protrude into the glandular lumen creating a hobnail appearance ⁵.

There are five histologic variants that are comparable with the phases of normal endometrium and the associated degree of atypical cells present ¹:

• minimal atypia: usually seen at the beginning of gestation with minimal hypertrophied nuclei and in limited numbers

• early secretory pattern: resembles normal early secretory endometrium with glandular cells having a marked number of centrally located hypertrophied nuclei arranged in a palisading fashion with subnuclear or supranuclear vacuoles

• secretory or hypersecretory pattern: hypertrophied glandular cells with a compact pyknotic hyperchromatic nuclei and a diffuse centronuclear cytoplasmic vacuolization ³

• regenerative, proliferative, or nonsecretory pattern: hypertrophied glandular cells display a vesicular chromatin pattern with minimal secretory activity; usually found in cases of hydatidiform mole, choriocarcinoma and ectopic pregnancy ¹

• monstrous cell pattern: rare, all cells display a giant and bizarre nuclei with a dense homogeneous chromatin and frequent pseudoinclusions

Differential diagnosis

• herpetic infection

• adenocarcinoma: endometrial or fallopian

• metaplastic papillary tumor of the fallopian tube

• endometrial clear cell carcinoma ⁶

• atypical mucinous cystoadenomas

• germinal inclusion cysts

• paratubal cysts