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.
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 humanplacental 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.