Arias-Stella reaction, also Arias-Stella phenomenon, is a benign change in the endometrium associated with the presence of chorionic tissue.^[1]

Arias-Stella reaction is due to progesterone primarily. Cytologically, it looks like a malignancy and, historically, it was diagnosed as endometrial cancer.^[1]

Significance

It is significant only because it can be misdiagnosed as a cancer. It may be seen in a completely normal pregnancy.

Diagnosis

It is characterized by nuclear enlargement and may also have any of the following: an irregular nuclear membrane, granular chromatin, centronuclear vacuolization, and pseudonuclear inclusions.^[1]

Five subtypes are recognized:^[1]

1. Minimal atypia.
2. Early secretory pattern.
3. Secretory or hypersecretory pattern.
4. Regenerative, proliferative or nonsecretory pattern.
5. Monstrous cell pattern.

History

It was first described by Javier Arias Stella, a Peruvian pathologist, in 1954.^[2]

See also

• Choriocarcinoma
• Chorioangioma
• Herpes
• Nuclear atypia
• Nuclear pleomorphism

Molar ectopic

References

Bibliography

• Textbook of Obstetrics by D.C. Dutta Page no. 180. ISBN 81-7381-142-3