Journal of Postgraduate Medicine Medknow Publications and Staff Society of Seth GS Medical College and KEM Hospital, Mumbai, India ISSN: 0022-3859 EISSN: 0972-2823 Vol. 48, Num. 3, 2002, pp. 211-212

Journal of Postgraduate Medicine, Vol. 48, Issue 3, 2002 pp. 211-212

Placental Site Trophoblastic Tumour

Agarwal N, Parul, Kriplani A, Vijayaraghavan M*

Departments of Obstetrics and Gynaecology and Pathology,* All India Institute of Medical Sciences New Delhi, India.
Address for Correspondence: Alka Kriplani, MD, Department of Obstetrics and Gynaecology, All India Institute of Medical Sciences, New Delhi - 110 029, India. E-mail: kriplani@medinst.ernet.in

Code Number: jp02072

A 27-years-old woman married for 5 years with history of twin delivery 2¹/₂ years ago, had irregular vaginal bleeding for last 10 months. She underwent dilatation and curettage (D & C) twice which showed secretary endometrium. Her Beta-hCG values were 5632 MIU/ml and she received methotrexate for gestational trophoblastic disease. But her bleeding persisted, bhCG level reached to 8000 MIU/ml. There was a growth of 4x4 cm in uterine cavity on ultrasound and colour Doppler revealed high velocity flow. Repeat curettage depicted a picture of placental site trophoblastic tumour (PSTT) on histopathology (Figure 1). There were sheets of intermediate trophoblast with marked nuclear pleomorphism and 3-5 mitotic figures/10 high power field (HPF). No syncytiotrophoblastic cells were identified. There was diffuse positivity to cytokeratin with foci of necrosis, lymphocyte infiltration fibrin deposition and inner third myometrial invasion. Stains for bhCG and human placental lactogen (HPL) could not be done.

On failure to respond to methotrexate, total abdominal hysterectomy was done. Both the ovaries were normal. On cut section of uterine endometrial cavity was partly filled by firm polypoidal mass of 3.5 x 2.5 x 2 cm, arising from fundus, similar nodule of 0.5 x 0.05cm was there at internal os (Figure 2). Myometrium was superficially infiltrated. Histological features were consistent with PSTT.

Discussion

Placental site trophoblastic tumour (PSTT) is the rarest variant of gestational trophoblastic disease which differs histologically, and immunochemically from gestational choriocarcinoma. Though considered a disease of reproductive age, reports have shown detection of PSTT even up to age of 66 years.¹ It can occur as early as 1 week or as late as 17 years after abortion, normal delivery or molar pregnancy.¹ Vaginal bleeding, is the most common symptom; it can present with amenorrhoea, galactorrhoea, nephrotic syndrome or just raised serum bhCG .²

Diagnosis of PSTT is often difficult and delayed. Histopathology of curettings is equivocal many times and so diagnosis is not recognised until operation. In equivocal case intense HPL positively, ultrastructural image and determination of HPL with bhCG are recommended.³ Median concentration of bhCG has been reported as 191 mIU/ml (range 33-20710MIU/ml).⁴

Up to 10% of cases have been reported to have metastasis outside the uterus at presentation. High mitotic index i.e. mitotic figures >5/10 HPF is reported to be associated with increased incidence of metastatic disease.

The clinical behaviour of PSTT varies and prediction of its biological behaviour remains difficult.⁵ WHO prognostic scoring system also doses not correlate well with clinical course of PSTT. However poor prognostic factors are an internal of >2 years from known antecedent pregnancy, mitotic count >5/10 HPF, extensive necrosis and extension outside the uterus. But tumour size, depth of myometrial involvement and vascular involvement do not seem to be predictors of outcome.⁶ Risk of death is reported 14 times greater if mitotic figures were greater than 5/10 HPF. High mitotic index is associated with not only metastatic disease but appears to be an indicator of recurrence too.⁷

Generally poor response to chemotherapy is reported and all cases ultimately undergo hysterectomy. But now complete long term remission is reported with multiagent chemotherapy in cases of PSTT.⁸ Chemotherapy is usually reserved for postoperative recurrence and those with high mitotic index.

The possibility of PSTT should be kept in mind in cases with GTD who fail to show a fall in bhCG after chemotherapy. Since disease has an unpredictable course and poor response to chemotherapy simple hysterectomy remains the mainstay of treatment.

References

1. Colsan LE, Kong CS, Zaloudcke. Epitheloid trophoblastic tumour of uterus in post menopausal women, a case report and review of literature. Am J Surg Pathol 2000; 24:1558-62.
2. Eckstein RP, Paradinas FJ, Bagshawe KD. Placental site trophoblastic tumour (trophoblastic pseudo-tumour). A study of four cases requiring hysterectomy including one fetal case. Histopathology 1982; 6: 211-66.
3. Arato G, Fulop V, Degrell P, Seizatvari I. Placental site trophoblastic tumour clinical and pathological report of two cases. Pathol Oncol Res 2000; 6: 292-4.
4. Newlands ES, Bower M, Fisher RA, Pardinas FJ. Management of placental site trophoblastic tumours. J Reprod Med 1998;43:53-9.
5. Aggarwal N, Sawhney H, Vasishta K, Pathak N, Saraw RK, Nijhawan R. Metastatic placental site trophoblastic tumor, a case report. J Obstet Gynacol Res 2001;27:49-52.
6. Bower M, Paradinas FJ, Fisher RA, Nicholson SK, Rustin GJ, Begen RH, et al. Placental site trophoblastic tumour molecular analysis and clinical experience. Clin Cancer Res 1996; 2: 897-902.
7. Feltmate CM, Genest DR, Wise L, Bernstein MR, Goldstein DP, Berkowitz RS. Placental site trophoblastic tumours, a 17 year experience at the New England Trophoblastic disease centre. Gynecol Oncol 2001;82:415-9.
8. Mangili G, Garavaglia E, De Marzi P, Zanetto F, Taccagni G. Metastatic placental site trophoblastic tumor. Report of a case with complete response to chemotherapy. J Reprod Med 2001;46:259-62.

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