Placental site nodule occurring in a fallopian tube

Extrauterine Placental Site Trophoblastic Tumor Involving the Vagina

Very few cases of placental site trophoblastic tumor (PSTT) primarily involving extrauterine sites have been reported to date. We report a case of a 29-year-old female who presented with a vaginal nodule 9 months after delivery at an outside hospital which was initially diagnosed as a poorly differentiated squamous cell carcinoma. Subsequently she was referred to our institute, and on the basis of histology, mildly elevated serum β-HCG level, and immunohistochemistry, PSTT was diagnosed. After the completion of chemotherapy, the vaginal nodule completely regressed and serum β-hCG returned to baseline. Her follow-up has been unremarkable. This case highlights the importance of the fact that PSTT can be easily misdiagnosed at extrauterine sites in the absence of proper clinical, histologic, and immunohistochemical correlation.

Atypical placental site nodule (APSN) and association with malignant gestational trophoblastic disease; a clinicopathologic study of 21 cases

The WHO Classification of Gestational Trophoblastic Tumors classifies placental site nodule (PSN) as a benign tumor-like trophoblastic neoplasm. Cases of PSN with atypical features were described [atypical placental site nodule (APSN)] and we started registering APSN in our unit in 2005. The aim of this study is to present our initial experience with these lesions. The Trophoblastic Disease Unit database was searched to identify all patients who were either referred with, or on review were diagnosed with, APSN from September 2005 to May 2013. Case notes and the pathology findings for these patients were retrieved and reviewed. A total of 21 cases of APSN were included, 3 of which were associated with gestational trophoblastic neoplasm on follow-up or review. Malignant gestational trophoblastic disease was associated with 3/21 (14%) cases of APSN, either concurrently or developing/manifesting within 16 mo of APSN diagnosis. None of these patients had raised serum hCG levels either at presentation or follow-up. Presence of APSN should indicate a thorough clinical and radiologic investigation and follow-up if diagnosed on curettage specimens. With increased recognition of this entity and corresponding larger series with longer follow-up, more accurate patient counseling will be possible.

Discovery of a cell: reflections on the checkered history of intermediate trophoblast and update on its nature and pathologic manifestations

In 1976, a series of 12 cases describing a lesion that had previously not been well characterized was reported as "trophoblastic pseudotumor of the uterus." Up until that time rare reports of the lesion had classified it most often as an unusual type of sarcoma associated with pregnancy. All patients in that series were alive and well except for one who died from complications of a uterine perforation occurring at the time of a diagnostic curettage. Thus, it appeared to be a benign neoplasm but subsequently it was found that some exhibited malignant behavior and the tumor was renamed "placental site trophoblastic tumor." A variety of observations pointed to an origin in a distinctive cell of the placental site, designated "intermediate trophoblast," which physiologically is seen in the normal implantation site. Subsequently, another subset of intermediate trophoblast cells originating from the chorion laeve have been shown to give rise to the placental site nodule/plaque, a well-circumscribed and usually microscopic incidental finding as well as the epithelioid trophoblastic tumor, its putative malignant counterpart. The initial description of "trophoblastic pseudotumor" opened a new area of research which brought to bear immunohistochemical and molecular genetic analyses that eventually has led to new insights in the diverse morphologic changes occurring in early placentation and also led to the development of a new classification of trophoblastic tumors and tumor-like lesions.

Incidental placental site nodule in a fallopian tube

A placental site nodule is a benign proliferation of intermediate trophoblasts from a previous gestation that failed to completely involute. It is a rare entity that is often asymptomatic and is usually found incidentally weeks or even years after the pregnancy. The most common location for placental site nodules is in the uterus within the endometrium and occasionally in the cervix, diagnosed by uterine curettings or hysterectomy. However, rare extrauterine cases have been documented and should be considered as a differential diagnosis when encountered in locations such as the fallopian tube. Here, we present a case of a 28-year-old woman with a history of spontaneous abortions who was found to have a placental site nodule of the fallopian tube after postpartum tubal ligation.

Spindle cell ossifying amyloidotic tumor of the fallopian tube

We report a unique tumor of the fallopian tube that was an incidental finding in a 60-year-old woman. The tumor was characterized by nests of spindle cells embedded in a partially ossified, hyalinized stroma, that also contained amyloid and basement membrane-like material. The histologic appearance of the tumor cells suggested an epithelial nature, but no immunohistochemical or ultrastructural evidence of such was found. The circumscription of the tumor and its lack of mitotic activity and cytologic atypia suggest a benign nature, but the histogenesis and appropriate classification of the tumor remain unclear.

Extrauterine Lesions of Intermediate Trophoblast

Lesions of intermediate trophoblast arising in the uterus include exaggerated placental site, placental site nodule, placental site trophoblastic tumor (PSTT), and epithelioid trophoblastic tumor. Only 12 examples of extrauterine lesions of intermediate trophoblast (ELIT) have been previously reported; 7 new cases are described herein. Six lesions were located in the fallopian tube or paratubal region and one in the ovary. The patients were 25 to 47 (average 36) years of age. The lesions ranged from 0.6 to 4 cm in diameter; four were cystic. The four placental site nodules (three tubal, one paratubal) were composed of small, sharply circumscribed nodules of intermediate trophoblast with no mitotic activity. The three PSTTs (two tubal, one ovarian) exhibited irregular stromal infiltration by intermediate trophoblast, mitotic activity, and necrosis. Chronic salpingitis was seen in the six tubal/paratubal cases, and endometriosis was seen in four cases. Immunoreactivity for human placental lactogen, human chorionic gonadotropin, and cytokeratin in two cases was consistent with an origin from intermediate trophoblast. ELITs presumably arise from previous ectopic pregnancies, a history of which was present in two of these patients. Follow-up, available on two of the three patients with PSTT, was uneventful at 6 and 12 years, but study of additional cases is necessary to reliably determine the behavior of extrauterine PSTTs.

The pathology of intermediate trophoblastic tumors and tumor-like lesions

An intermediate trophoblast is a distinctive trophoblastic cell population from which four trophoblastic lesions are thought to arise: exaggerated placental site (EPS), placental site nodule (PSN), placental site trophoblastic tumor (PSTT), and epithelioid trophoblastic tumor (ETT). EPSs and PSTTs are related to the differentiation of the intermediate trophoblast in the implantation site (implantation site intermediate trophoblast), whereas PSNs and ETTs are related to the intermediate trophoblast of the chorion laeve (chorionic-type intermediate trophoblast). EPSs and PSNs are nonneoplastic lesions, whereas PSTTs and ETTs are neoplasms with a potential for local invasion and metastasis. Microscopically, intermediate trophoblastic lesions can be confused with a variety of trophoblastic and nontrophoblastic tumors, but an appreciation of the morphologic features and immunophenotype allows their diagnosis to be relatively straightforward in most instances. Correct diagnosis is important because each of these lesions may require different therapeutic approaches.

Old ectopic pregnancy remnants with morphological features of placental site nodule occurring in fallopian tube and broad ligament

Placental site nodule (PSN) is an asymptomatic benign proliferation of intermediate trophoblast from a previous gestation that failed to involute. It is most commonly found in the endometrium or endocervix; however, placental site nodule has recently been reported to occur at sites of ectopic gestation. This is the first case of PSN in the broad ligament in direct contact with the fallopian tube. The patient underwent surgery for an adenocarcinoma of the opposite tube. Microscopically and immunohistochemically, the lesion showed the characteristics of a proliferation of intermediate trophoblast.

An immunohistochemical study of the rete ovarii and epoophoron

A study to compare the immuno-histochemical profile of the human rete ovarii, and epoophoron, with the Fallopian tube and ovarian surface epithelium was performed with 31 antibodies and antisera. A reaction was present in the epithelial cytoplasm of the rete ovarii and epoophoron of mesonephric origin, for vimentin, GFAP, cytokeratin markers, (AE1/AE3, MNF116; Cam 5.2, 34 beta E12 and for the monospecific antibodies to cytokeratins 7 and 19), heat shock protein 27, in the cell membrane for HBME-1, EMA and in the subepithelial collagen for collagen IV. Reactions were present only in the epithelium in the rete ovarii for EGFR (one case) and CA-125 (four cases). A reaction was present in the epithelium of the epoophoron only for Ber-EP-4 and S100. There was no reaction with antibodies for desmin, neurofilament protein, cytokeratins 20 or 14, actin, calretinin, E-cadherin, C-erb-B2, or CEA (monoclonal and polyclonal reagents). The immuno-histochemical profile of the Fallopian tube was consistent with its para-mesonephric origin and that in the ovarian surface epithelium was consistent with a proposed modified mesothelial origin. This study provides an immunohistochemical profile of these structures with a large panel of commonly available antibodies and antisera, confirming and extending the findings described in previous studies.

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

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 multiclefted. Hyalinization 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, 34 beta E12, 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.

Pregnancy with primary tubal placental site trophoblastic tumor--A case report and literature review

Placental site trophoblastic tumor (PSTT) is a rare trophoblastic neoplasm with malignant potential. The diagnosis and prognosis of this rare disease remain difficult. A case of tubal PSTT with the primary manifestation of internal bleeding at 30 weeks' gestation is presented. Emergency exploratory laparotomy and right partial salpingectomy were performed initially. Total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy were done immediately after cesarean section at 34 weeks' gestation. No further adjuvant therapy was given after surgery. No evidence of tumor recurrence or signs of metastasis were noted during 12 months of follow-up. Heterotopic pregnancy, one with intrauterine normal pregnancy and the other with implanting in the right fallopian tube and placental site trophoblastic tumor transformation, was proposed. To our knowledge, this is the first such case in the English literature.