Multiple pulmonary metastases with halo-sign from malignant mixed Müllerian tumors.

The lungs are one of the most common organs to which cancer metastasizes, but are a location not common for uterine sarcoma. A malignant mixed Müllerian tumor (MMMT) of the uterus is an extremely rare and aggressive sarcoma, characterized by a mixture of epithelial and mesenchymal components. There are few reports regarding the pulmonary metastasis from MMMTs. The present study presents the case of a 58-year-old woman with hemoptysis and post-menopausal vaginal bleeding. The woman was initially diagnosed with invasive aspergillosis based on a chest computed tomography (CT) scan showing multiple pulmonary nodular opacities surrounded by a ground-glass attenuation halo (halo-sign). Diagnostic curettage and a percutaneous CT-guided lung biopsy were conducted for the pathological diagnosis. Finally, the diagnosis was confirmed as MMMT with lung metastasis based on the histopathological examination of cervical canals, uterus and lung specimens, which showed a mixture of carcinomatous and sarcomatous elements, and morphology exhibiting hyperchromatic nuclei and necrosis. Immunohistochemical staining was positive for vimentin, focally positive for p16, and negative for napsin, cytokeratin 7 (CK7), CK20, carcinoembryonic antigen, carbohydrate antigen 125, homeobox protein CDX2 and villin in the lung specimens. This case highlights that pulmonary metastatic tumor from uterine sarcoma can present as halo-sign, which is commonly observed in pulmonary aspergillosis. Therefore, it needs to be considered in the differential diagnosis of such lesions, and pathological confirmation is required.