A placental site nodule, abbreviated PSN, is benign remnant from a previous pregnancy.
PSN are diagnosed by examining the tissue under a microscope, usually obtained with a dilation and curettage.
Typically, they consist of pink (hyaline) material using the standard stain and contain few cells. Bizarre multinucleated cells may be present; however, there is no mitotic activity. The differential diagnosis includes (cervical) squamous cell carcinoma and exaggerated placental site.
PSN are benign. Once removed, they do not require any treatment and do not recur.