Pathogenesis of Benign Metastasizing Leiomyoma: A Review

Metastasizing leiomyoma to heart

Cardiac smooth muscle tumors are rare. Three different clinical settings for these tumors have been reported, including benign metastasizing leiomyoma from the uterus, primary cardiac leiomyoma and leiomyosarcoma, and intravenous cardiac extension of pelvic leiomyoma, which is the most common. We present a case of a 55-year-old woman with a benign metastasizing leiomyoma to the heart 17 years after hysterectomy and 16 years after metastasis to the lung. Immunohistochemical stains for smooth muscle actin, desmin, and estrogen and progesterone receptors were positive, indicating a smooth muscle tumor of uterine origin. To our knowledge, this is only the fourth reported case of benign metastasizing leiomyoma to the heart and the first case of long-delayed cardiac metastasis after successful treatment of pulmonary metastasis. It illustrates that benign metastasizing leiomyoma should be included in the differential diagnosis of cardiac tumors in patients with a history of uterine leiomyoma, especially when associated with pulmonary metastasis.

Benign Metastasizing Leiomyomas to the Lungs: An Institutional Case Series and a Review of the Recent Literature

BACKGROUND

Benign metastasizing leiomyomas (BMLs) represent the extrauterine spread of a benign uterine process. Pulmonary BMLs are the most common example of distant spread of uterine leiomyomas and are usually found incidentally in premenopausal women. The rarity of BMLs accounts for the limited literature that currently exists regarding their underlying pathophysiology, disease course, and management.

METHODS

A retrospective analysis was performed of all BML cases diagnosed and managed at Brigham and Women's Hospital during a 22-year period. The demographic and clinical characteristics of these patients were compared with a PubMed-derived cohort of BML cases reported since 2006.

RESULTS

Benign metastasizing leiomyoma tumors were identified in 10 Brigham and Women's Hospital patients, whereas 57 cases were reported in the literature. The average age at diagnosis was 54.1 and 46.7 years, respectively. Mean interval time from a pertinent gynecologic procedure to BML diagnosis was 23 years at Brigham and Women's Hospital. All patients demonstrated positivity for actin, desmin, and estrogen/progesterone receptors, confirming the diagnosis of uterine leiomyomas. Management primarily consisted of diagnostic resection with subsequent observation with or without hormonal suppression for residual pulmonary nodules. Progression of residual BMLs was noticed in 30% and 8.3% of Brigham and Women's Hospital and literature patients, respectively, when follow-up was reported. One patient in our series required further surgical management.

CONCLUSIONS

Benign metastasizing leiomyomas are a rare cause of pulmonary nodules. They likely represent a clonal spread of uterine leiomyomas to the lungs. Management includes pathologic diagnosis with long-term surveillance with or without hormonal manipulation.

Single-port laparoscopic debulking surgery of variant benign metastatic leiomyomatosis with simultaneous lymphatic spreading and intraperitoneal seeding

Benign metastatic leiomyomatosis (BML) is a rare disease characterized by smooth muscle cell proliferation in extrauterine sites including the lung, abdomen, pelvis, and retroperitoneum. Depending on location, BML is classified as intravenous leiomyomatosis and diffuse peritoneal leiomyomatosis. Pathogenesis of BML can be iatrogenic after previous myomectomy or hysterectomy, hormonal, or coelomic metaplasia. Treatment options are observation, hormonal suppression, and/or surgical debulking via laparotomy or laparoscopy. Laparoscopic surgery is gaining in popularity in the gynecologic field compared to laparotomic surgery and single-port laparoscopy has the benefits of cosmesis and early tissue extraction by transumbilical morcellation. We report a 39-year-old woman with BML who underwent single-port laparoscopy debulking surgery.

What are MRI findings of Spine Benign Metastasizing Leiomyoma? Case report with literature review

INTRODUCTION

Benign Metastasizing Leiomyoma (BML) is a rare disease that results from metastasis of uterine leiomyoma to distant sites with benign pathologic features. Spine BML is very rare so the information of its features and pathophysiology is seldom known.

MATERIALS AND METHODS

We experienced a case of 42-year-old woman who presented with right buttock and leg pain with paresthesia. She had a surgical history of uterine myomectomy. Magnetic resonance imaging (MRI) of the lumbar spine revealed a well-circumscribed mass lesion in the posterior compartment of the L4 vertebral body, with extension into the ventral epidural space and both foramina. The mass showed hypointensity on T1-, T2-weighted images and strong homogeneous enhancement on gadolinium enhanced T1-weighted images. Tumor removal was conducted, and permanent biopsy revealed the mass as leiomyoma. Nine previous spine BML reports, which are known for all, were reviewed along with our case. We collated the clinical information and MRI findings of spine BML to figure out its common denominators.

RESULTS

Premenopausal women, previous history of uterine myoma, myomectomy/hysterectomy, and lung BML seemed to be predisposing clinical factors. For the imaging findings, posterior vertebral body invasion with bony destruction, neural foramen invasion, and canal encroachment were shown as common denominators. Especially in MRI findings, low T1 and T2 signal intensities with strong homogeneous enhancement were their common features.

CONCLUSION

We gathered the fragmentary information of the spine BML for the first time, especially the MRI findings. Although spine BML is rare, it surely exists. Accordingly, spine surgeons should be suspicious of spine BML given its typical clinical history and MRI findings.

Incidental benign metastasizing leiomyoma in a patient with bone sarcoma: a case report

Background. The benign metastasizing leiomyoma is an exceptionally rare entity; it presents with ectopic leiomyoma nodules with a benign pattern. Symptoms vary according to the anatomic location. The diagnosis is histopathological, usually in patients with history of hysterectomy. Case Presentation. A 36-year-old female with 2-month history of left knee pain was diagnosed with bone fibrosarcoma. A CT scan showed pulmonary nodules. The patient started neoadjuvant chemotherapy. Conservative surgery of pelvic limb was achieved. A new CT scan reported pulmonary nodules that remained in relation to the previous CT. A nodule resection by thoracotomy and TOB (transoperative biopsy) was performed. The final pathology report described benign proliferative lesions consistent with benign metastatic leiomyoma. Conclusions. Benign metastatic leiomyoma is a rare condition presenting with uterine and extrauterine nodules most commonly in the lung. The diagnosis is histopathological. The surgical procedure must be reserved for selected patients.

Case of concurrent benign metastasizing leiomyoma in the lung and retroperitoneum, with a focus on its etiology

We report a rare, simultaneous occurrence of benign metastasizing leiomyoma in the lung and retroperitoneum in a 49-year-old woman who had previously undergone myomectomy at 35 years of age and hysterectomy at 45 years of age for multiple recurrences of histologically benign uterine leiomyomas. At 49 years of age, computed tomography-guided biopsy indicated benign metastasizing leiomyomas in the lung. In addition, a retroperitoneal leiomyoma was found that was resected along with both the ovaries via laparotomy. No sign or symptom of recurrence was observed 5 years later. The coexistence of benign metastasizing leiomyoma in the lung and retroperitoneum following surgery for conventional leiomyomas has rarely been reported. Further, the nature and etiology of benign metastasizing leiomyoma are still not well understood. This case is therefore worth reporting, and exploring its etiology is important.

Intraspinal leiomyoma: A case report and literature review

Leiomyomas are benign tumors which are predominantly found in the genitourinary and gastrointestinal tracts. Leiomyomas in the spine are extremely rare. The current study presents a case of a 35-year-old female with intraspinal leiomyoma who presented with low back pain and weakness in the left leg of two months. Computerized tomography and magnetic resonance imaging revealed an epidural mass at the T11-12 levels. The patient underwent a T11-12 laminectomy through posterior approach, achieving total removal of the tumor with a well-demarcated dissection plane. Pathological examination demonstrated a leiomyoma. Postoperatively, the patient showed a significant improvement in neurological function. Although intraspinal leiomyoma is extremely rare, it should be considered in the differential diagnosis of spinal lesions in females. The diagnosis is predominantly dependent on a pathological examination. Gross total resection is recommended for its treatment, however the prognosis remains poor. Post-operative hormonal therapy may be useful in controlling tumor recurrence.

Multiple metastases from histologically benign intraarticular diffuse-type tenosynovial giant cell tumor: a case report

Diffuse-type tenosynovial giant cell tumor (D-TGCT) is a relatively rare mesenchymal tumor. It is a locally aggressive but virtually nonmetastasizing neoplasm and thus regarded as benign. Only a few D-TGCTs with benign histology have been reported to metastasize. We report an extremely rare case of benign D-TGCT in which multiple metastases developed 9 years after surgery for the primary tumor. The present case suggests that conventional D-TGCT has the potential to form distant metastases, albeit exceptionally rarely, and that this probable implantation phenomenon can be managed conservatively.

A rare case of primary pulmonary artery myofibroblastic sarcoma--imaging and pathologic features

Primary myofibroblastic sarcomas of the pulmonary artery are very uncommon, but early detection is critical. Common clinical symptoms include shortness of breath, chest discomfort, and syncope. Patients diagnosed with a pulmonary tumor have a high risk of fatal pulmonary embolism. In this case study, we identified and diagnosed pulmonary artery myofibroblastic sarcoma in a young man by its imaging and pathologic characters. Surgery to excise the tumor was successfully performed and the operation was considered to have improved his prognosis. Postoperative examinations did not show any evidence of residual tumor, recurrence, or metastasis in the lungs or cardiac tissue. Based on the results of this case study, we concluded that the imaging and pathologic features of primary pulmonary artery myofibroblastic sarcoma can assist physicians in making a prompt diagnosis and an immediate surgical and treatment plan to greatly improve prognosis.

Uterine-specific loss of Tsc2 leads to myometrial tumors in both the uterus and lungs

Lymphangioleiomyomatosis (LAM) is a rare disease characterized by proliferation of abnormal smooth-muscle cells in the lungs, leading to functional loss and sometimes lung transplantation. Although the origin of LAM cells is unknown, several features of LAM provide clues. First, LAM cells contain inactivating mutations in genes encoding Tsc1 or Tsc2, proteins that limit mTORC1 activity. Second, LAM tumors recur after lung transplantation, suggesting a metastatic pathogenesis. Third, LAM is found almost exclusively in women. Finally, LAM shares features with uterine leiomyomas, benign tumors of myometrial cells. From these observations, we proposed that LAM cells might originate from uterine leiomyomas containing Tsc mutations. To test our hypothesis, and to develop mouse models for leiomyoma and LAM, we targeted Tsc2 deletion primarily in uterine cells. In fact, nearly 100% of uteri from uterine-specific Tsc2 knockout mice developed myometrial proliferation and uterine leiomyomas by 12 and 24 weeks, respectively. Myometrial proliferation and mTORC1/S6 activity were abrogated by the mTORC1 inhibitor rapamycin or by elimination of sex steroid production through ovariectomy or aromatase inhibition. In ovariectomized Tsc2 null mice, mTORC1/S6 activity and myometrial growth were restored by estrogen but not progesterone. Thus, even without Tsc2, estrogen appears to be required for myometrial mTORC1/S6 signaling and proliferation. Finally, we found Tsc2 null myometrial tumors in lungs of older Tsc2 uterine-specific knockout females, suggesting that lung LAM-like myometrial lesions may indeed originate from the uterus. This mouse model may improve our understanding of LAM and leiomyomas and might lead to novel therapeutic strategies for both diseases.

Novel hormone treatment of benign metastasizing leiomyoma: an analysis of five cases and literature review

OBJECTIVE

To evaluate novel hormonal therapies in patients with unresectable benign metastasizing leiomyoma (BML) disease.

DESIGN

Case series.

SETTING

National Institutes of Health (NIH).

PATIENT(S)

Five subjects with the diagnosis of BML based on imaging and/or histopathologic diagnosis.

INTERVENTION(S)

Four patients were treated with single or combination therapy of leuprolide acetate and/or an aromatase inhibitor. One patient was treated with an antiprogestin (CDB-2914).

MAIN OUTCOME MEASURE(S)

Response to therapy was measured by tumor burden on cross-sectional imaging employing RECIST (Response Evaluation Criteria in Solid Tumors) 1.1 guidelines.

RESULT(S)

Four patients treated with single or combination therapy of leuprolide acetate and/or an aromatase inhibitor demonstrated stable disease with reduction in tumor burden. The fifth patient treated with antiprogestin (CDB-2914) had degeneration of her tumor, progression of its size, and an improvement in symptoms.

CONCLUSION(S)

Hormone treatment with GnRH agonist and/or aromatase inhibition may be a therapeutic option to reduce tumor burden in unresectable BML disease or for those patients who wish to avoid surgical intervention. RECIST 1.1 guidelines, while traditionally used to evaluate tumor response to cancer therapeutics, may be useful in evaluating BML tumor burden response to hormone therapy.

Effect of lichong decoction on expression of IGF-I and proliferating cell nuclear antigen mRNA in rat model of uterine leiomyoma

OBJECTIVE

To study the effect of Lichong Decoction (Lichong Decoction for strengthening anti-pathogenic Qi and eliminating blood stasis) on the expression of insulin-like growth factor-I (IGF-I) and proliferating cell nuclear antigen (PCNA) mRNA in a rat model of uterine leiomyoma.

METHODS

Fifty female Wistar rats were randomized into a normal control group, model group, Lichong Decoction group, Guizhifuling Capsule (Capsule containing Cassia Twig and Poria) group, and Mifepristone group. The uterine leiomyoma model was established by peritoneal injections of exogenous estrogen and progesterone hormone. The ultrastructural changes in cells of rat uterine tissues were observed with transmission electron microscopy, and the expression of IGF-I and PCNA mRNA was detected by real-time fluorescent quantitative PCR.

RESULTS

Following treatment, cells in the Lichong Decoction group appeared to be arranged normally, the cellular morphology were almost in a normal state, hyperplasia and hypertrophy of the chondriosome was reduced, collagen fibers were arranged in a regular manner, without obvious hyperplasia, and the expression of IGF-I and PCNA mRNA was significantly decreased compared with the model group (P < 0.01).

CONCLUSIONS

The effect of Lichong Decoction on uterine leiomyoma is related to its function in reducing the expression of IGF-I and PCNA mRNA.

Spontaneous regression of metastatic pulmonary leiomyoma after resection of contralateral metastatic mass

Pulmonary benign metastatic leiomyoma is a rare entity with a debated pathogenesis. We report a case in which benign metastatic leiomyoma involving the lung had spontaneously regressed after debulking surgery. Although no adjuvant treatment was done, the remaining masses regressed significantly in the 1-year follow-up image.

Targeted approaches toward understanding and treating pulmonary lymphangioleiomyomatosis (LAM)

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease found almost exclusively in women that is characterized by neoplastic growth of atypical smooth muscle-like cells in the lung, destruction of lung parenchyma, and obstruction of lymphatics. These processes lead to the formation of lung cysts, rupture of which results in spontaneous pneumothorax. Progression of LAM often results in loss of pulmonary function and death. LAM affects predominantly women of childbearing age and is exacerbated by pregnancy. The only proven treatment for LAM is lung transplantation, and even then LAM cells will often return to the transplanted lung. However, methodical and targeted approaches toward understanding LAM pathophysiology have led to the discovery of new potential therapeutic avenues. For example, the mutational inactivation of tumor suppressor complex genes tuberous sclerosis complex 1 or tuberous sclerosis complex 2 has been shown to be present in lung LAM cells. These mutations occur sporadically or in association with inherited hamartoma syndrome tuberous sclerosis (TSC). Since TSC genes function as negative regulators of the mammalian target of rapamycin, a major controller of cell growth, metabolism, and survival, rapamycin analogs have recently been used to treat LAM patients with promising results. Similarly, studies focusing on the importance of estrogen in LAM progression have suggested that anti-estrogen therapy might prove to be an alternative means of treating LAM. This minireview summarizes recent progress in understanding LAM pathophysiology, including the latest preclinical and clinical studies, and insights regarding the role of hormones in LAM.

Genomic imbalances in benign metastasizing leiomyoma: characterization by conventional karyotypic, fluorescence in situ hybridization, and whole genome SNP array analysis

Benign metastasizing leiomyoma, a rare condition of controversial origin, is characterized by the occurrence of extrauterine smooth muscle tumors primarily affecting the lungs of women with a history of uterine leiomyomas. Numerous genetic studies of uterine leiomyoma with rearrangements of the HMGA2 and HMGA1 loci defined in prominent subgroups have been conducted. In contrast, cytogenetic and molecular descriptions of benign metastasizing leiomyoma are few, and, in particular, this entity has not been previously subjected to single nucleotide polymorphism (SNP) array analysis. In this study, conventional karyotypic, and/or molecular cytogenetic, and SNP array characterization of a pleuropulmonary benign mestasizing leiomyoma and a synchronous deep soft tissue leiomyoma of the thigh, which arose in a 56-year-old female with a remote history of uterine leiomyomata, revealed rearrangement of the HMGA1 (6p21) locus and nearly identical genomic profiles, including loss of chromosome 7 material in both lesions. These findings suggest that both the deep soft tissue and pleuropulmonary lesions were derived from the same abnormal clone and are genetically related to uterine leiomyomata.

Etiology, diagnosis, and management of uterine leiomyomas

Uterine leiomyomas are the most common benign gynecologic tumors. While the true etiology of leiomyomas remains unknown, their origin is thought to be multifactorial including genetic, hormonal, and tissue growth factor variations. Leiomyomas are predominantly found in women of reproductive age and are the leading indication for hysterectomy worldwide. Menstrual irregularities, pain, and fertility difficulties may arise from leiomyoma presence, although many women remain asymptomatic. Diagnosis can be made via ultrasound or magnetic resonance imaging, when precise mapping of the tissue is needed. Many treatment options are available ranging from surgical to medical and should be chosen depending on symptom severity, number and size of leiomyomas, patient age, fertility desires, and patient preferences. The objective of this article is to present a practical clinical perspective on uterine leiomyomas and an overview of contemporary treatment options.

A novel saline infusion sonohysterography-based strain imaging approach for evaluation of uterine abnormalities in vivo: preliminary results

In this article, we demonstrate the feasibility of saline infusion sonohysterography-based strain imaging for the determination of stiffness variations in uterine masses in vivo. Strain images are estimated using a 2-dimensional multilevel hybrid algorithm developed for sector array ultrasound transducers. Coarse displacements are initially estimated using envelope echo signals, followed by a guided finer displacement estimation using window lengths on the order of 6 wavelengths and 7 A-lines on radiofrequency data. Strain images are obtained by estimating displacement slopes using least squares estimation. In this prospective study, we show that stiffer masses such as fibroids appear darker or as regions with low strain on strain images and are thus clearly differentiated when compared to normal uterine tissue. A high strain boundary around stiffer masses referred to as a "halo" due to increased slipping or sliding of the mass during the applied deformation is also visualized. Uterine polyps, on the other hand, are visualized as masses that are brighter or regions with high strain when compared to the background myometrium, indicating the presence of a softer mass. Axial strain images provide additional new information that may supplement current clinical B-mode imaging used for the diagnosis of uterine abnormalities. Our results show the feasibility of improving clinical diagnosis based on strain imaging.

Thoracic neoplasms at the Jena reference center for soft tissue tumors

INTRODUCTION

The Jena Soft Tissue Tumor Reference Center is the major German pathology institute for consultation of malignant mesenchymal tumors. Here, we present the clinicopathological data on thoracic soft tissue tumors of a two-year period.

METHODS

The tumors were analyzed according to their localization, type (soft tissue tumor, other tumor type, non-neoplastic lesion) and biological behavior. The frequency of the defined soft tissue tumor entities were considered after categorizing the cases according to the WHO Classification of Tumors. Gender and age were also assessed.

RESULTS

In total, 1,071 cases of thoracic tumors were recorded within the 2 years. The majority were non-epithelial lesions (75.3%, n = 806/1,071), of which 68.1% (n = 549/806) were malignant or intermediate malignant. 107 non-epithelial lesions involved the lung and 37 the pleura. By far the most common lung and pleural tumors were undifferentiated sarcomas. In the lung, other frequent entities were solitary fibrous tumors, synovial sarcomas and leiomyosarcomas. We also recorded 13 non-epithelial tumors of the heart and 66 tumors of the breast with angiosarcomas being the most frequent subtype. There was a female predominance for vascular neoplasms, while men prevailed for adipocytic tumors.

CONCLUSIONS

Our study provides information about the frequency, distribution, age and gender of patients with thoracic soft tissue tumors including several rare entities. Thus, it may help in the differential diagnosis of these neoplasms. In addition, we present a model highlighting the potential progression of lung carcinoma to undifferentiated sarcoma via the process of epithelial-mesenchymal transition.

Multifocal osteolytic lesions within lumbar spine in a middle-aged Chinese woman: a benign metastasizing leiomyoma?

STUDY DESIGN

Case report.

OBJECTIVE

To describe a case presented as osteolytic lesions involving 2 inconsecutive lumbar, which was pathologically proved to be of smooth muscular origin.

SUMMARY OF BACKGROUND DATA

Smooth muscle tumor of uncertain malignant potential (STUMP) could be diagnosed when the neoplasm showed some malignant behavior, whereas its histologic image revealed very low malignance. A 47-year-old woman presented with low back pain and numbness of the left lower extremity attributable to osteolytic lesions in the second and fourth lumbar vertebral bodies, which was subsequently diagnosed as STUMP. A benign metastasizing leiomyoma was highly suspected.

METHODS

Clinical, pathologic, and radiologic characters of the patient with STUMP confined within the lumbar spine were retrospectively reviewed. A mini review was also conducted.

RESULTS

We describe the first spine-confined case of STUMP.

CONCLUSION

Significant new information in the growing literature of this rare and newly identified diagnosis has addressed the need for orthopedists to consider the STUMP diagnosis.

[Primary endobronchial leiomyoma--endoscopic laser resection]

Leiomyomas account for less than 2% of all benign lung tumors. Only one third is endobronchial in location, usually presenting as primary solitary lesions and airway obstruction findings. Literature on primary endobronchial leiomyomas is therefore scarce, with a few more than 100 cases being reported. We describe a case of a 44-year-old female that presented with bronchial asthma like symptoms and an obstructive pneumonia, due to a right main bronchus primary leiomyoma that was successfully resected using Nd:YAG laser through rigid bronchoscopy. Purpose of this case is to enhance the rarity of primary endobronchial leiomyoma diagnosis and report the relevance of laser resection in its definitive treatment. A brief review on lung leiomyomas is discussed over the text.

Decoding melanoma metastasis

Metastasis accounts for the vast majority of morbidity and mortality associated with melanoma. Evidence suggests melanoma has a predilection for metastasis to particular organs. Experimental analyses have begun to shed light on the mechanisms regulating melanoma metastasis and organ specificity, but these analyses are complicated by observations of metastatic dormancy and dissemination of melanocytes that are not yet fully malignant. Additionally, tumor extrinsic factors in the microenvironment, both at the site of the primary tumor and the site of metastasis, play important roles in mediating the metastatic process. As metastasis research moves forward, paradigms explaining melanoma metastasis as a step-wise process must also reflect the temporal complexity and heterogeneity in progression of this disease. Genetic drivers of melanoma as well as extrinsic regulators of disease spread, particularly those that mediate metastasis to specific organs, must also be incorporated into newer models of melanoma metastasis.