Pulmonary metastases of uterine endometrial stromal sarcoma (ESS) are un com-mon. 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.
Adult ; Endometrial Neoplasms/*pathology/radiography ; Female ; Humans ; Lung Neoplasms/*pathology/radiography/*secondary ; Sarcoma, Endometrial Stromal/*pathology/radiography/*secondary

OBJECTIVETo study the morphologic feature, immunohistochemistry phenotype of ESS and its metastases, with emphasis on the histogenesis, tumor differentiation and diagnostic criteria.

METHODSThe pathologic features of 15 cases and 4 metastases were studied. The immunohistochemical study was performed on selected sections by a panel of antibodies including CD10, smooth muscle actin, estrogen and progesterone receptors, keratin (AE1/3) and alpha-inhibin.

RESULTSPatients were 22 to 75 years of age (mean 45). The endometrial stromal component predomominated in 7 cases. Three cases showed a picture of smooth muscle differentiation. Endometrial stromal sarcoma with fibromyxoid features were present in 2 cases. There were 3 sarcomas of poorly differentiated. The morphology features of the metastatic foci in 3 of the 4 metastasis cases were not similar to that of the primary counterpart in uteri. Among 14 ESS and 4 metastases, 15 of 18, 5 of 18, 7 of 18, and 10 of 18 were positive for CD10, SMA, ER and PR, respectively. AE1/3 and alpha-inhibin were only positive in the adenomatous area of ESS. Strong expression of SMA was obtained in all 10 cellular leiomyomas, and CD10 was only weakly expressed in 1 case (P < 0.05).

CONCLUSIONSESS are morphologically heterogeneous with multipotential differentiation. The histologic features of the metastases may not be similar to those of the primary. CD10 and SMA are diagnostically useful markers for ESS.

Actins ; metabolism ; Adult ; Aged ; Cell Differentiation ; Endometrial Neoplasms ; metabolism ; pathology ; Female ; Humans ; Lung Neoplasms ; diagnostic imaging ; metabolism ; secondary ; Middle Aged ; Muscle, Smooth ; pathology ; Neoplasm Recurrence, Local ; Neprilysin ; metabolism ; Radiography ; Sarcoma, Endometrial Stromal ; metabolism ; secondary ; Uterus ; metabolism ; pathology