Imaging features of thoracic metastases from gynecologic neoplasms.

Gynecologic malignancies are a heterogeneous group of common neoplasms and represent the fourth most common malignancy in women. Thoracic metastases exhibit various imaging patterns and are usually associated with locally invasive primary neoplasms with intra-abdominal spread. However, thoracic involvement may also occur many months to years after initial diagnosis or as an isolated finding in patients without evidence of intra-abdominal neoplastic involvement. Thoracic metastases from endometrial carcinoma typically manifest as pulmonary nodules and lymphadenopathy. Thoracic metastases from ovarian cancer often manifest with small pleural effusions and subtle pleural nodules. Thoracic metastases to the lungs, lymph nodes, and pleura may also exhibit calcification and mimic granulomatous disease. Metastases from fallopian tube carcinomas exhibit imaging features identical to those of ovarian cancers. Most cervical cancers are of squamous histology, and while solid pulmonary metastases are more common, cavitary metastases occur with some frequency. Metastatic choriocarcinoma to the lung characteristically manifests with solid pulmonary nodules. Some pulmonary metastases from gynecologic malignancies exhibit characteristic features such as cavitation (in squamous cell cervical cancer) and the "halo" sign (in hemorrhagic metastatic choriocarcinoma) at computed tomography (CT). However, metastases from common gynecologic malignancies may be subtle and indolent and may mimic benign conditions such as intrapulmonary lymph nodes and remote granulomatous disease. Therefore, radiologists should consider the presence of locoregional disease as well as elevated tumor marker levels when interpreting imaging studies because subtle imaging findings may represent metastatic disease. Positron emission tomography/CT may be helpful in identifying early locoregional and distant tumor spread.