A Case of Benign Metastasizing Leiomyoma with Multiple Metastasis to the Soft Tissue, Skeletal Muscle, Lung and Breast
A 39-year-old woman was referred to our hospital. At the age of 19, she was treated for miliary pulmonary tuberculosis because multiple pulmonary nodules were found on her chest radiograph, although she had no symptoms. At the age of 31, she was diagnosed uterine leiomyoma, but she was not treated; four years later, she underwent myomectomy. At the age of 39, she visited a local clinic due to bilateral, multiple small nodular lesions that were seen on a chest radiograph and both breasts had palpable breast masses. She had undergone excisional biopsy of the breast before being referred to our hospital.\nThe patient was asymptomatic on admission to our clinic, but bilateral, multiple small nodular lesions were still noted on the chest radiograph (). There was no abnormality on the physical examination, and her breathing sounds were clear. A complete blood count, blood chemistry, c-reactive protein, arterial blood gas analysis and pulmonary function test were all within the normal ranges. The serum levels of tumor markers including alpha-fetoprotein (AFP), squamous cell carcinoma (SCC) antigen and carcinoembryonic antigen (CEA), CA19-9, CA-125 and CA15-3 were within the normal ranges.\nThe chest radiograph showed multiple, variable-sized nodules in both lungs, suggesting hematogenous metastasis (). Chest CT scans with intravenous contrast enhancement demonstrated multiple well-enhancing masses in both breasts (), the left pectoralis minor muscle (), and the right infraspinatus muscle (). A CT scan obtained with a lung window setting showed multiple variable-sized nodules in both lungs, which suggested hematogenous metastasis (not shown).\nWe initially planned to treat her with progesterone under the clinical impression of BML or lymphangioleiomyomatosis (LAM). However, the follow-up chest radiologic findings showed progressive disease, and so we performed a hysterectomy, bilateral oophorectomy and wedge resection of the lung for the purpose of both treatment and diagnosis.\nThe pathologic findings of the lung, breast (), and retroperitoneal tissue showed nodular proliferations of spindle cells. The tumor showed occasional mitotic activity (4-7/50HPF) (), but no nuclear atypia, hemorrhage or necrosis. Immunohistochemial staining of the lung mass showed a positive reaction for smooth muscle actin and a negative reaction for thyroid transcription factor-1 (TTF-1), a 10% positive cell area with a weak intensity for estrogen receptor, a 95% positive cell area with a strong intensity for progesterone receptor and a low mitotic index (less than 5%) for Ki-67.\nAfter surgical hormonal ablation, she was prescribed tamoxifen. Follow-up chest radiography () showed the decreased size of the multiple nodular lesions. This response has been sustained until the present.