Clinicopathological study of Gestational Trophoblastic Diseases with Immunohistochemistry using P57 to Differentiate between Complete Mole and Partial Mole

INTRODUCTION: Gestational Trophoblastic Diseases (GTD) are characterized by abnormal proliferation of different trophoblastic cells during placentation. Gestational Trophoblastic Diseases include complete mole, partial mole, invasive mole, placental site trophoblastic tumor and choriocarcinoma. They are pregnancy related tumors and patients are unaware of the condition. They are clinically diagnosed as missed abortions and undergo evacuation and curettage only. So the chances of missing molar pregnancy is higher. The incidence of gestational trophoblastic diseases is higher in India and it is important to identify these cases since there is a higher incidence of molar pregnancies progressing to choriocarcinoma, a highly metastasizing neoplasm. AIM OF THE STUDY: To determine the incidence of Hydatidiform mole, invasive mole, persistent trophoblastic disease and choriocarcinoma and to evaluate the histomorphological features of Gestational Trophoblastic Diseases with light microscopy and special stains. p57kip2 an immunohistochemical marker has been used to differentiate between complete and partial mole. MATERIALS AND METHODS: The study is conducted between three year period from October 2008 to September 2011. The total number of pregnancies encountered in the three years period was 34,649and from October 2008 to September 2009 total no of live births reported was 11954.A total of 13,593 biopsies were received in the department of pathology, Thanjavur medical college during the period of 3 years. Among these, 326 were gynecological neoplasms. The analysis of biopsies and hysterectomy specimens revealed 55 cases of hydatidiform mole, 1 case of invasive mole, 6 cases of choriocarcinoma and 1 case of persistent trophoblastic disease. RESULTS: The spectrum of gestational trophoblastic disease included in this study were hydatidiform mole 55(87.3%), invasive mole 1 (1.58%), choriocarcinoma 6 (9.5%). The incidence of gestational trophoblastic diseases is found to be 1 in 550. The incidence of hydatidiform mole is found to be 1 in 630 pregnancies, incidence of invasive mole is found to be 1 in 35714 pregnancies and the incidence of choriocarcinoma is found to be 1 in 5780 pregnancies. Among the 326 gynecological neoplasms, gestational trophoblastic diseases constituted 19.32% .Hydatidiform mole was found to be highest in the age group of 21 – 30 years (70.9%), whereas choriocarcinoma was widely distributed in the age group of 21 – 40 years. Hydatidiform mole were more common in the primi gravida followed by para 3 and para 2. Choriocarcinoma was found to have an equal occurrence in 2nd, 3rd and 4th parity. Complete mole constituted about 69.08% of cases and partial mole constituted about 30.9% cases of total hydatidiform mole. The incidence of gestational trophoblastic diseases was found to be 1 in 597 live births. Choriocarcinoma following an antecedent molar pregnancy and term pregnancy have an equal incidence. PAS - special stains are of some help in identifying mucoid stroma in early complete hydatidiform mole. Immunohistochemistry for P 57 kip2 is used as an adjuvant marker in differentiating early complete mole, complete mole and partial mole in difficult cases and also for confirmation.