Lung Metastasis From Uterine Leiomyosarcoma: A Case Report and Literature Review on Pulmonary Metastasis Presenting as Both Solid and Cystic Lesions

Uterine leiomyosarcoma is a rare, aggressive tumor that arises from the uterine smooth muscle cells. It has a poor prognosis, and distant metastasis is common. While pulmonary metastasis often presents as solid nodules, it may occasionally present as cystic lesions that can result in pneumothorax. Here, we describe a case of a 66-year-old woman with recurrent pulmonary metastasis secondary to uterine leiomyosarcoma who had different presentations of the same pathology. She was first diagnosed with stage 1B pT1bN0M0 uterine leiomyosarcoma and underwent a laparotomy and total hysterectomy and bilateral salpingo-oophorectomy (THBSO) with pelvic and para-aortic lymph node dissections. She declined adjuvant chemotherapy and was on close surveillance. Four years later, she was found to have a right upper lobe solid nodule that was confirmed to be metastatic leiomyosarcoma on biopsy, and she underwent a wedge resection of the lesion. A year later, she developed a new left apical cystic lesion associated with moderate left hydropneumothorax. She underwent a wedge resection of this lesion with talc pleurodesis, and histology confirmed metastatic uterine leiomyosarcoma. We reviewed the existing literature and postulated potential mechanisms and risk factors for the development of malignancy-associated pneumothorax.