Uterine smooth muscle tumor of uncertain malignant potential: A rare cause of multiple pulmonary nodules
A case of a 51-year-old woman, gravida 0 - para 0, who was admitted with progressive dyspnea on exertion is presented. The past medical history revealed that 3 years ago and due to persisting menorrhagia, the patient underwent dilatation and curettage. Histopathology report indicated the presence of abnormal endometrial hyperplasia. As the symptoms were persisting, the woman underwent total abdominal hysterectomy. Histopathologically, after thorough gross processing of the specimen, an intramural smooth muscle tumor of the uterus with a diameter measuring 5 cm was identified and six (6) sections from the tumor were obtained. Microscopy showed mild mitotic activity (2–6 MF/10 HPF), moderate nuclear atypia and lack of tumor necrosis []. A second typical leiomyoma, adenomyosis and sparse areas of thin-walled arteriolar type (plexiform) vessels were also identified but with no typical indication of endometrial malignancy present. Immunohistochemistry revealed focally mild immunopositivity regarding Vimentin and CD10. Extensive sampling was done to exclude the possibility of leiomyosarcoma. The absence of necrosis and atypical mitosis made pathologists consider that the tumor belongs to the so-called “grey zone” or STUMP. Therefore, no further treatment was applied and close follow-up was decided.\nChest X-ray and chest computed tomography (CT) confirmed the presence of bilateral pulmonary nodules []. As multiple metastases due to tumor of unknown origin were suspected, the patient underwent a series of diagnostic tests: brain and abdomen CTs, gastroscopy, colonoscopy, bronchoscopy, mammography, thyroid ultrasound and skeletal scintigraphy, none of which indicated primary extrapulmonary tumor. The patient underwent video-assisted thoracoscopy and multiple lung biopsies were performed. Histopathology and immunohistochemical examination of the specimens showed pulmonary parenchyma with focuses of sarcoma. A metastatic malignant smooth muscle cells neoplasm with uterine origin was diagnosed []. Cell nuclei presented diffuse moderate mitotic activity (6 MF/10 HPF), but there were also some atypical mitoses. The immunohistochemical examination revealed that the tumor was positive in Desmin and smooth muscle actin (SMA) and negative in CD117 and CD34. Pleural fluid was also found positive for metastatic malignancy. Both pathology and cytopathology reports excluded that the condition was associated with benign metastasizing leiomyoma.\nThe patient underwent 14 cycles of chemotherapy, with multiple drug combinations, including ifosfamide, epirubicin, docetaxel, gemcitabine, bevacizumab, cisplatin, cyclophosphamide and vincristine. She died 11 months later due to disease progression.