Gestational Trophoblastic Disease

Abstract

Gestational trophoblastic disease (GTD) encompasses a heterogeneous group of lesions, including hydatidiform mole, invasive mole, choriocarcinoma, and placental site trophoblastic tumor, that are characterized by an abnormal proliferation of trophoblastic tissue. Some of these lesions are true neoplasms, whereas others represent abnormally formed placentas that have a predisposition to neoplastic transformation of the trophoblast. The literature on this subject is extensive but confusing because of differences in classification and terminology that have been applied. The necessity of a morphologic classification has been questioned, since the current management is largely medical and often conducted in the absence of a histologic diagnosis. Thus, all trophoblastic lesions are frequently combined under the rubric of gestational trophoblastic disease without applying specific pathologic terms. Recent cytogenetic and immunocytochemical studies have demonstrated profound differences in the etiology, morphology, and clinical behavior of various forms of the disease, underscoring the importance of a uniform histologic classification to facilitate standardized reporting of data and to ensure appropriate clinical management.