Extrauterine (tubal) placental site nodule

Aims: The clinicopathological and immunohistochemical features of the second case of placental site nodule (PSN) of extrauterine, tubal location are presented, Methods and results: The lesion was incidentally found in the right tube during a cesarean section and eventual tubal ligation in a 23-year-old women gesta 2 para 1, after an uneventful 39-week intrauterine pregnancy, Grossly, the right Fallopian tube had a 1 cm dilatation filled by necrotic material, Microscopically, the lumen of the Fallopian tube was effaced and replaced by a rim of pleomorphic intermediate trophoblastic (IT) cells with pseudoinvasive parietal features which were positive for human placental lactogen, placental alkaline phosphatase, epithelial membrane antigen and CAM5,2. The Ki67 index was 3%, Conclusion: Due to its bizarre microscopic appearance, this lesion should be included in the differential diagnosis with malignant conditions, Both origins from a previous subclinical extrauterine tubal pregnancy and a possible migration of IT from a uterine implantation are considered.