Pulmonary metastases of uterine endometrial stromal sarcoma: diffuse micronodular and ground glass opacities: a case report

Pulmonary metastases of uterine endometrial stromal sarcoma (ESS) are uncommon. The patterns of uterine ESS metastasis to the lung are multiple pulmonary nodules, single nodule, or cystic lesions. Pulmonary intraalveolar micronodular metastases of uterine ESS are unusual and have not been reported. We experienced a case of metastatic uterine ESS presenting as pulmonary diffuse micronodules with ground glass opacities on chest computed tomography of a 37-yr-old woman who previously underwent hysterectomy due to low grade ESS of the uterus four years ago. The histologic findings of video assisted thoracotomy biopsy showed numerous intraalveolar polypoid micronodules protruding from the alveolar septums. All tumor nodules were composed of short spindle cells arranged in ill-defined whorls, and nuclear feature and sparse cytoplasm were seen in uterine ESS. Immunohistochemically, these cells showed strong nuclear staining for estrogen receptor and progesterone receptor, and diffuse cytoplasmic staining for CD10.