Whole exome sequencing of benign pulmonary metastasizing leiomyoma reveals mutation in the BMP8B gene

Whole exon capture sequencing for identifying mutations associated with pulmonary benign metastasising leiomyoma

A woman in her early 20s presented with cough and fever. She had undergone an abdominal myomectomy 3 years ago for uterine leiomyoma. Chest CT and positron emission tomography-CT revealed multiple round nodules in both lungs, suggesting metastatic lesions. A CT-guided lung biopsy was performed, and the tumour was diagnosed as pulmonary benign metastasising leiomyoma (PBML) based on pathological analyses. Whole exon capture sequencing of uterine leiomyoma and PBML sections revealed that 13 genes (MCM10, SLC16A9, RAG1, BAZ1A, NLRP2, TRMT61B, CPXM1, NGLY1, SUCLG2, FAM13A, CAGE1, PHTF2 and ZDHHC2) were concurrently present in the two tumours. The patient was prescribed goserelin injections every 4 weeks. The symptoms improved 2 weeks after starting the treatment. The lung nodules considerably decreased in size after three courses of goserelin treatment. The nodular size continues to decrease with the treatment.

Concurrent Benign Metastasizing Leiomyoma in the Abdominal Wall and Pelvic Cavity: A Case Report and Review of the Literature

Benign metastatic leiomyoma (BML) is a histologically benign disease with invasive biological behavior. Most patients are women of childbearing age with a history of uterine leiomyoma. The progress of the disease is relatively slow, the prognosis is good, and most patients can survive for a long time. The lung is the common metastatic site, and BML with metastatic lesions outside the lung is very rare. A 37-year-old woman with multiple BML in the abdominal wall and pelvic cavity after uterine leiomyoma surgery was admitted to our hospital. Combined with the clinical data of this case and reviewing the relevant literature, this paper discusses the pathological characteristics, diagnosis, differential diagnosis, and treatment of BML.

Pulmonary benign metastasising leiomyoma: a single-institution case series

Background

Benign metastasising leiomyoma (BML) is a rare and often asymptomatic presentation of smooth muscle tumour of uterine origin, occurring outside the uterus. We present the first case series of pulmonary BML in a contemporary UK population.

Patients were identified from prospective histopathological databases spanning from 2003 to 2019. Data was collected retrospectively from physical and electronic data sources.

Results

Six post-menopausal females were identified with an average age of 44±8 years (mean±SD). Fifty percent of our cohort was asymptomatic with an incidental finding of pulmonary nodules, whilst the others complained of non-specific respiratory symptoms. Five patients (88%) had multiple lesions (median 9, range 2 to 12)—with bilateral distribution, measuring an average of 11 mm (range 7 to 27) in size on cross-sectional imaging. All patients underwent diagnostic surgical pulmonary wedge resection, with no perioperative morbidity.

Immunohistochemistry confirmed the presence of ‘spindle cells’, staining positive for smooth muscle actin, desmin and progesterone receptors for all patients (100%), and oestrogen receptors in five patients (87%). Four patients (67%) underwent a hysterectomy prior to diagnosis of BML and one (17%) due to the diagnosis itself. Four patients (67%) underwent oophorectomy, whilst one patient required hormonal suppression therapy. Survival was 100% at a median follow-up of 59.5 months (range 29 to 166).

Conclusions

BML is a rare clinical entity accounting for a small proportion of patients presenting with pulmonary nodules. Following successful tissue diagnosis, outcomes with conservative or medical management are excellent.

Molecular and clinicopathologic characterization of intravenous leiomyomatosis

Intravenous leiomyomatosis (IVL) is an unusual uterine smooth muscle proliferation that can be associated with aggressive clinical behavior despite a histologically benign appearance. It has some overlapping molecular characteristics with both uterine leiomyoma and leiomyosarcoma based on limited genetic data. In this study, we assessed the clinical and morphological characteristics of 28 IVL and their correlation with molecular features and protein expression, using array comparative genomic hybridization (aCGH) and Cyclin D1, p16, phosphorylated-Rb, SMARCB1, SOX10, CAIX, SDHB and FH immunohistochemistry. The most common morphologies were cellular (n = 15), usual (n = 11), and vascular (n = 5; including 3 cellular IVL showing both vascular and cellular features). Among the immunohistochemical findings, the most striking was that all IVL showed differential expression of either p16 or Cyclin D1 in comparison to surrounding nonneoplastic tissue. Cytoplasmic phosphorylated-Rb was present in all but one IVL with hyalinization. SMARCB1, FH, and SDHB were retained; S0X10 and CAIX were not expressed. The most common genetic alterations involved 1p (39%), 22q (36%), 2q (29%), 1q (25%), 13q (21%), and 14q (21%). Hierarchical clustering analysis of recurrent aberrations revealed three molecular groups: Groups 1 (29%) and 2 (18%) with associated del(22q), and Group 3 (18%) with del(10q). The remaining IVL had nonspecific or no alterations by aCGH. Genomic index scores were calculated for all cases and showed no significant difference between the 14 IVL associated with aggressive clinical behavior (extrauterine extension or recurrence) and those without (median scores 5.15 vs 3.5). Among the 5 IVL associated with recurrence, 4 had a vascular morphology and 3 had alterations of 8q. Recurrent chromosome alterations detected herein overlap with those observed in the spectrum of uterine smooth muscle tumors and involve genes implicated in mesenchymal tumors at different sites with distinct morphological features.

Reasons to Reconsider Risk Associated With Power Morcellation of Uterine Fibroids

Our insights into the molecular pathogenesis of uterine smooth muscle tumors have improved significantly. Accordingly, in the present review, we advocate a more refined risk assessment for patients considering surgical removal of fibroids or hysterectomy, respectively, requiring morcellation. For this procedure, the risk estimates given for the iatrogenic spread of a previously unexpected malignancy considerably vary among different studies. Nearly all previous studies conducted retrospectively refer to the risk of a patient having an unexpected malignancy at the time of surgery. We feel that, more appropriately, risk should refer to the number of tumors because, as a rule, every single nodule arises independently and, thus, carries an independent risk of being malignant or not. Furthermore, whether so-called parasitic fibroids carry an underestimated risk of stepwise malignant transformation is discussed.

Benign leiomyoma with multiple metastases to vertebrae and calvarium: An index case with comprehensive review of endocrine targets

"Benign" metastatic leiomyomas (BML) are indolently growing metastatic tumors which mostly associate with uterine leiomyomas in women in reproductive ages. The reason to define these lesions as "benign" despite metastasis is their pathological features with low mitotic counts, lack of or minimal nuclear atypia, pseudocyst formation, and coagulative necrosis unlike leiomyosarcomas. Despite lack of pathological malignant features, they may cause significant morbidity and even mortality. Here, we describe a BML case with metastases to vertebrae and skull bones. Vertebral and skull metastases of BMLs were very rarely reported. In treatment of these tumors, hysterectomy and GnRH modifier treatments are widely employed. GnRH agonists act by desensitization and downregulation of the GnRH receptors, while GnRH antagonists act via the canonical competitive blockage. These treatments reduce FSH and LH levels, thereby reducing the systemic levels of sex steroids which stimulate leiomyoma growth. However, leiomyomas inherently harbor aromatase activity and synthesize their own estrogen; hence, treatment with systemic estrogen antagonists may provide better tumor control. Another important factor in BML pathogenesis is progesterone, and both progesterone receptor antagonists and high-dose progesterone receptor agonists may reduce BML growth. Following surgical treatment of the calvarial mass and radiotherapy of the vertebral metastatic foci, our BML case was successfully managed with hysterectomy and anastrozole treatment. Higher awareness of BML cases and their molecular endocrinological features in the neurosurgical community may pave to develop better strategies for treatment of these tumors causing high morbidity.

Cancer Genes Mutations in Benign Metastasizing Leiomyoma: A Case Report

Benign metastasizing leiomyoma is a very uncommon clinicopathologic entity with unknown molecular pathogenesis. We present a case of a 40-year-old woman who has a history of surgical resection of a large uterine leiomyoma and then subsequently presented with benign metastasizing leiomyomas to her lungs. Due to her tumor being estrogen receptor (ER) positive and progesterone receptor (PR) positive, she was empirically treated with anastrozole with sustained clinical benefit. Molecular studies with Foundation One testing showed low mutational burden and mutational variants in five known cancer genes. Our findings have important clinical and pathogenetic implication for metastasizing uterine leiomyoma.