INTRODUCTION

The most common mode of secondary tumor involvement of the uterine corpus or cervix is by direct extension, most often from a colorectal or bladder neoplasm. Most patients with such involvement also have concomitant invasion of other pelvic organs. Metastases to the uterus are not nearly as common, but the frequency and variety of metastatic tumors involving the uterus has increased in the last two decades due to improved imaging and improved chemotherapy for many solid tumors with consequent improved survival. Metastases occur secondary to other primary genital tract tumors as well as extragenital sources.

OTHER PRIMARY GENITAL TRACT TUMORS

Secondary involvement from other genital site primary tumors generally occurs as a result of direct spread from cervical, tubal, or ovarian cancers. However, implantation, either on the cervical mucosa or endometrium, is becoming recognized with increasing frequency (Figure 16.1). The cervical mucosal implants may be endometrial, tubal, or ovarian in origin, while the endometrial implants generally arise from tubal or ovarian sites. In many instances, the site of origin is conjecture and, in some cases, simultaneous primary sites cannot be completely excluded. Although no single approach to this problem resolves these distinctions, a combination of the distributional pattern in conjunction with histologic and immunohistologic similarities (or differences) of tumors in different tumor sites can point to one or another diagnosis. Specific locational attributes may also be useful (i.e., WT1 tends to be expressed in pelvic (non-uterine) serous carcinomas, while uterine serous carcinomas usually do not express WT1).