Multiple pulmonary nodules is a concerning finding, with a large range of differential diagnosis. Etiologies included metastatic cancer, infection, sarcoidosis, and less commonly parenchymal disease. The following case describes a rare occurrence of metastatic leiyomyoma.
A 49 year old Hispanic female nonsmoker with hypertension and uterine fibroids had complaints of a dry cough, but denied dyspnea, hemoptysis, fever, chills, weight loss or night sweats. Multiple pulmonary nodules were noted on a chest radiograph taken for a preoperative evaluation for hysterectomy. The computed tomography of the chest revealed multiple pulmonary nodules in bilateral lung fields (See figure 1), with the largest nodule measuring 1cm. A CT guided biopsy was attempted without a conclusive result and subsequently the patient underwent a wedge biopsy of her right middle lobe. The pathology revealed bundles of spindle cell, smooth muscle cells with bland, elongated nuclei (See figure 2). Immunostaining shows the spindle cells are positive for smooth muscle actin, desmin, and vimentin; it was negative for pancytokeratin and S100 suggesting benign metastasizing leiyomyoma.Patient was started on a progesterone receptor agonist and subsequent chest imaging has revealed diminished number and size of the pulmonary nodules.
BML is rare disease, first described in 1939 by Dr Steiner, that is been described in the literature in patients with a history of benign uterine leiomyomata (vast majority after undergoing myomectomy or hysterectomy) that present with multiple pulmonary nodules that are histologically similar to the resected leiomyoma.Classification is controversial and still debated; it is described as a low grade leiomyosarcoma, implantation & proliferation of benign smooth muscle tissue via hematogenous spread, or a systemic leiomyomatosis with multifocal, yet independent smooth muscle proliferation. There are studies showing that there is a similar immunohistochemical profile (estrogen receptor (ER) positive, progesterone receptor (PR) positive, and low proliferative index.) Review of literature (case reports) there was a median survival of 43 months after lung biopsy. Due to uterine origin, medical treatment with selective ER/PR modulators might be effective in diminishing the size of the nodules.
As our patient presented with multiple pulmonary nodules antecedent to her hysterectomy for uterine fibroids, the presence of pulmonary nodules in a patient with a history of a uterine fibroids with or without hysterectomy, should raise the concern of metastasized leiyomyoma.
Manoj Mammen, No Financial Disclosure Information; No Product/Research Disclosure Information