Placental site nodules and plaques: a clinicopathological and immunohistochemical study of 25 cases with ultrastructural findings

• Published in: Pathology 1999-11, Vol.31 (4), p.328-336
• Main Authors: Santos, Leonardo D., Fernando, Sujatha S.E., Yong, James L.C., Killingsworth, Murray C., Juan Wu, Xiao, Kennerson, Alan R.
• Format: Article
• Language: English
• Subjects: 34βE12; Adolescent; Adult; Biological and medical sciences; Biomarkers, Tumor - analysis; CAM 5.2; Cell Nucleus - ultrastructure; Cytoplasm - ultrastructure; electron microscopy; Endometrium - pathology; Female; Female genital diseases; Gynecology. Andrology. Obstetrics; Humans; Immunoenzyme Techniques; immunohistochemistry; intermediate trophoblast; low and high molecular weight cytokeratin; Medical sciences; Placenta Diseases - metabolism; Placenta Diseases - pathology; Placental site nodules and plaques; Pregnancy; Trophoblasts - metabolism; Trophoblasts - pathology; Trophoblasts - ultrastructure; Tumors
• ISSN: 0031-3025; 1465-3931
• DOI: 10.1080/003130299104684

Placental site nodules or plaques (PSN-Ps) are nodular benign lesions of the intermediate trophoblast (IT) cells in the endometrium, endocervix, superficial myometrium or fallopian tube, occurring after a remote intrauterine pregnancy. We present a study of 25 cases of PSN-Ps These lesions occurred in patients aged 18 to 44 years. Most were discovered incidentally in endometrial curettage specimens. The specimens were received as part of clinical investigations for menorrhagia, per vaginal bleeding or pelvic pain. None of the PSN-Ps was visible grossly. Microscopically, they were mostly multiple, well-circumscribed, oval or plaque-like cellular nodules. The IT cells typically had abundant vacuolated or eosinophilic cytoplasm. The nuclei were irregular, large, hyperchromatic, often degenerate-looking and either mononucleated, multinucleated or multi-clefted. Hyalinisation surrounding individual or groups of IT cells, or located in the centre of the nodules, was a constant feature in all cases. The lesional cells were strongly immunoreactive to CAM 5.2, 34βE12, AE1/AE3, EMA and vimentin. Some cases showed focal positivity to HCG and HPL. PLAP staining was consistently negative. Ultrastructurally, the IT cells showed prominent nuclear variation in size and shape. The abundant, vacuolated cytoplasm contained some rough endoplasmic reticulum and loosely arranged filaments. This study describes the clinicopathological and immunophenotypic features of 25 cases of PSN-Ps including the ultrastructural findings of one case.