Endometrial Stromal Sarcoma Presented as an Incidental Lung Mass with Multiple Pulmonary Nodules
A 42-year-old woman was referred to Korea University Ansan Hospital for evaluation of suspicious lung mass with multiple pulmonary nodules. The lung lesions were incidentally found in a simple chest roentgenography during a routine medical inspection performed a month ago. She had a history of myomectomy seven years ago in local clinic in China, and the pathologic result was known to be as a benign uterine tumor, leiomyoma.\nAt admission, she was asymptomatic and physical examination showed unremarkable findings. A chest X-ray revealed a right perihilar lung mass with tiny peripheral nodules on right middle lung field. Chest CT scan showed a 4.5-cm sized well demarcated right perihilar mass with various sized multiple peripheral nodules on both lungs (). Her complete blood cell counts showed hemoglobin level of 14.0 g/dL, total leukocyte count of 7.50×109/L with 50.4% neutrophils and platelet count of 290×109/L. Blood biochemical results including blood urea nitrogen, creatinine, and liver function tests were unremarkable. Carcinoembryonic antigen, squamous cell carcinoma antigen, alpha-fetoprotein and beta human chorionic gonadotrophin also revealed values within normal range.\nInitially, she was suspected of primary lung malignancy with lung to lung metastasis, but radiologic findings of the mass and nodules were well demarcated without remarkable lymph node enlargement in mediastinum and hilum. These features also suggested a possibility of metastatic lung tumor from extrathoracic origin. Thereby, locoregional and systemic evaluations were undertaken to discover potential extrathoracic metastatic lesions and concealed primary malignant origin. Because she had a history of surgical resection on leiomyoma, systemic evaluations to search possible primary origin included a gynecologic inspection on the preferential basis. Through pelvic examination by the gynecologist, firm, non-tender, smooth intrapelvic mass was palpated over the symphysis pubis, and transvaginal ultrasonography revealed a mixed echogenic mass sizing approximately 16-week pregnant uterus. Further radiologic evaluations were undergone to characterize detailed structural features of the intrapelvic mass.\nAbdomen-pelvis CT scan discovered a 6.9×5.8-cm sized pelvic mass, and the mass showed a heterogeneous enhancement pattern with possible attachment to the adjacent intrapelvic structures. Magnetic resonance imaging was conducted for further delineation and characterization of the intrapelvic mass, and the lesion showed moderate enhancement in T1 weighted image with internal fibrovascular septum (). The mass was partially abutting to the uterine fundus in a possible outgrowing fashion. Initial radiologic impression of the intrapelvic mass was neoplasm from uterine origin including subserosal myoma or fibrous tumor such as malignant fibrous histocytoma. In positron emission tomography-CT scan, neither pulmonary lesions nor pelvic mass expressed hypermetabolisms typical of malignancy (). Maximum standardized uptake values of the intrapelvic mass and the right perihilar mass were 1.32 and 1.02, respectively. This finding was generally discordant with the initial impressions suggesting either primary pulmonary or metastatic malignancy. Furthermore, this feature potentially implied that both lung and pelvic mass were mutually sharing identical characteristics. Therefore, pathologic evaluation on both lung and pelvic mass was planned to confirm the diagnosis.\nBronchoscopic examination for the right perihilar mass showed no definite endobronchial lesion. Percutaneous needle biopsy for the right perihilar mass could not be performed because the location of the mass was just beside the right pulmonary artery and its branches. Therefore, surgical biopsy under general anesthesia was decided for the simultaneous pathologic diagnosis of both pelvic and lung mass.\nDiagnostic pelviscopy for intrapelvic mass and thoracoscopic right perihilar mass biopsy with wedge resection for right peripheral nodules were conducted. Intraoperative frozen biopsies showed small round malignant cells from pelvic and lung specimens, which was not compatible for typical non-small cell lung cancer. Intraoperative gross finding of the pelvic mass exhibited bulging appearance from the anterior side of the uterine fundus, and this suggested higher probability of uterine origin malignancy. Subsequently, diagnostic pelviscopy was converted into total abdominal hysterectomy with both salphingo-oophorectomy.\nHistopathologic examination for specimens from lung mass, uterus, both ovary and salpinx, and omentum showed same features to each other (). Bland looking small oval to spindle shaped cells with scanty cytoplasm and perivascular arrangement were observed on hematolxyline and eosin stain. These cells were infiltrating adjacent normal myometrium and pulmonary parenchymal structures. Immunohistochemical stain of the uterine specimen revealed positivites on estrogen and progesterone receptors, and CD10 (). However, cytokeratin, chromogranin, smooth muscle actin, and p53 were negative. These immunohistochemical features, especially positive to CD10, were identical to the findings of the right perihilar lung mass (). Based on these histopathological and immunohistochemical findings, the diagnosis of low-grade ESS with pulmonary metastasis was confirmed.\nAfter recovery from post-operative period, palliative chemotherapy with paclitaxel, adriamycin and cisplatin was initiated. Abdomen-pelvis CT scan after two cycles of chemotherapy showed no significant evidence of recurrence in the pelvic cavity. From the chest CT scan taken at this point of time, remnant right perihilar mass remained to be unchanged without any sign of disease progression, and there was no newly developed pulmonary nodule suggestive of metastasis.