A clinicopathological study of atypical leiomyomas: Benign variant leiomyoma or smooth-muscle tumor of uncertain malignant potential

A Case Report of a Uterine Smooth Muscle Tumor of Undetermined Malignant Potential (STUMP): A Diagnostic Dilemma and Management Challenges

Uterine smooth muscle tumors of undetermined malignant potential (STUMPs) are an uncommon kind of uterine smooth muscle tumor. It is distinguished by histopathologic and morphologic characteristics that are in between those of a benign leiomyoma and a malignant leiomyosarcoma. From a clinical standpoint, the clinical presentation of STUMP is similar to that of a fibroid. The diagnosis is usually confirmed after surgery. Here, we report the case of a 39-year-old woman who experienced increased menorrhagia, back pain, and pressure sensations during the past six months. She had a well-defined, freely movable lump in her lower abdomen, measuring the size of a 22-cm uterus. The patient exhibited pallor, and her imaging scan showed the presence of an intramural posterior uterine solid mass indistinguishable from fibroid measuring 8.5 × 9 cm. Goserelin acetate (Zoladex 3.6 mg implant) was recommended for a duration of six months. The patient experienced a significant amelioration in menorrhagia and discomfort. However, no reduction in the size of the mass was observed. Myomectomy was made for the suspicion of a malignant transformation. The histology examination confirmed the diagnosis of a STUMP; a hysterectomy was undergone, and the procedure went smoothly. The patient was discharged home in good condition with instructions for long-term follow-up due to a risk of recurrence of about 7%. The lack of standardized and clear clinical and diagnostic criteria for STUMP adds challenges to their management.

Ultrasound-guided microwave ablation for giant breast leiomyoma: A case report

Rationale

Breast leiomyoma is the rarest non-epithelial tumor of the breast. As a benign tumor, its main treatment is regular follow-up. Surgical treatment is often used in clinical practice when patients have symptoms or strongly require treatment. However, if the tumor is large or located around the nipple or areola, the cosmetic effect of surgery is not good, so it is urgent to find new treatment methods. We pioneered the use of microwave ablation in the treatment of giant breast leiomyoma and achieved good results.

Patient concerns

A 37-year-old female was admitted to hospital because she found a breast mass of approximately 8 cm. She had no obvious clinical symptoms, but had great psychological pressure.

Diagnosis

Pathological biopsy showed leiomyoma followingly the surgical operation of giant breast leiomyoma was planned. However, the breast mass was large, and the postoperative scar would affect the breast appearance.

Interventions

The consent was obtained from the patient and her family. The Ultrasound-guided microwave ablation was successfully performed.

Outcomes

The patient was followed up for 10 months, and the tumor volume ablation rate was 69.8%. The cosmetic effect of breast was excellent.

Lessons

To our knowledge, this is the first case to using microwave ablation (MWA) for the treatment of breast leiomyoma. Ultrasound-guided MWA can be used for the treatment of breast leiomyoma, especially when the mass is large and requires traditional surgical resection. It can effectively improve the breast aesthetics and further improve the quality of life of patients. However, it is only a case report, and needs more research to verify MWA in breast leiomyoma.

Acute abdomen with a parasitic smooth muscle tumor of uncertain malignant potential (STUMP) in pregnancy; a unique case report

INTRODUCTION AND IMPORTANCE

Diagnosis of a smooth muscle tumor of uncertain malignant potential (STUMP) during pregnancy is rare. Furthermore; the investigation of an intra-abdominal mass during pregnancy is clinically challenging due to anatomical changes and additional considerations of the developing fetus and radiation exposure. The unusual nature and diagnostic dilemma of such a case warrants a case report to serve as an educational prompt to clinicians who may encounter pregnant patients with undifferentiated intra-abdominal masses and/or suspecting of STUMP.

CASE PRESENTATION

We report a rare case of a parasitic STUMP diagnosed during pregnancy. The patient presented with a new umbilical hernia and deranged liver function tests (LFT's) during her third trimester. MRI reported a large mass in the left mid flank with intra-abdominal varices extending into the umbilical hernia. She went on to develop an acute abdomen requiring laparotomy where a parasitic fibroid adherent to the omentum was excised and a preterm infant was delivered via caesarean section. Histology was difficult due to pregnancy related changes but ultimately confirmed a diagnosis of STUMP.

CLINICAL DISCUSSION

STUMP in pregnancy is rare and diagnosis is further complicated by histological challenges due to pregnancy related changes. Postoperative diagnosis is challenging due to lack of universally accepted diagnostic criteria and Uncertainty regarding prognostic factors makes management and follow-up of patients with STUMP challenging. Studies have shown that younger patients are more likely to demonstrate recurrence.

CONCLUSION

Investigation and management of intra-abdominal masses in pregnancy is challenging. It requires timely multi-disciplinary team (MDT) input. Additional complications and considerations relate to the preterm fetus. Knowledge and understanding of these difficulties will better equip clinicians working with such patients to formulate a structured and well informed approach to the pregnant patient with a new intra-abdominal mass. Diagnosis of STUMP during pregnancy may be challenging for the pathologist and require further exert opinion.

Recurrence of Uterine Smooth Muscle Tumor of Uncertain Malignant Potential: A Systematic Review of the Literature

Background: This study aimed to systematically review the existing literature on uterine smooth muscle tumor of uncertain malignant potential (STUMP) to provide information about characteristics and outcomes of patients and the risk factors for recurrence over a period of 60 years (1960−2021). Methods: According to PRISMA guidelines, we searched for "uterine smooth muscle tumor of uncertain malignant potential" in PubMed (all fields) and Scopus (Title/Abstract/Keywords) databases (accessed on 1 January 2022). Relevant articles were obtained in full-text format and screened for additional references. The only filter used was the English language. Studies including full case description of patients with histopathological diagnosis of STUMP in accordance with Stanford criteria were included. Results: Thirty-four studies, including 189 cases, were included. The median age was 43 years, and in 21.5% of cases there was a recurrence of the disease. Bivariate analysis showed a significant association between use of morcellation without bag and risk of recurrence (p = 0.001). Unprotected morcellation during demolitive or conservative surgery was independently associated with a higher risk of disease recurrence with a relative risk of 2.94 (p < 0.001). A significant progressive decrease in the recurrence rate was observed over time (r = −0.671, p = 0.008). The percentage of patients who underwent surgery followed by in-bag protected morcellation significantly increased after the publication of the U.S. Food and Drug Administration alert about the risk linked to this procedure (p = 0.01). Conclusions: Unprotected morcellation of the lesion is associated with the relapse of the disease. However, this clinical condition showed a drastic decrease over time. This could likely be due to the increased awareness by surgeons of the importance of customizing surgical treatment.

Intraparenchymal breast leiomyoma and atypical leiomyoma

Background

Breast leiomyoma is a rare benign mesenchymal tumor, accounting for less than 1% of all breast neoplasms. Cases of breast atypical leiomyoma is even more rarely reported and its diagnostic criteria together with its clinical courses is not cleared defined.

Case presentation

We described two patients with breast leiomyomas. One has unilateral benign breast leiomyoma, the other one has bilateral breast leiomyomas. For the bilateral case, the left-side tumor was diagnosed as benign leiomyoma while the right-side tumor was diagnosed as atypical leiomyoma. The morphological features that lead to the diagnosis of atypical leiomyoma are its invasive growth pattern, mild nuclear atypia, and mitotic figures up to 3mitoses/10HPF.

Conclusions

Atypical breast leiomyoma appears to behave like benign leiomyoma without recurrence in our study with nine-year follow-up. Due to the limited experience, cases presented as atypical intraparenchymal breast leiomyoma should be closely followed.

Risk of Recurrence in Uterine Leiomyoma with Bizarre Nuclei: a Systematic Review and Meta-Analysis

Objective Leiomyoma with bizarre nuclei (LBN) is a variant of uterine leiomyoma, which has replaced the previous category of “atypical leiomyoma” and must be distinguished from smooth muscle tumors of uncertain malignant potential (STUMP). However, previously published series of “atypical leiomyoma” might have included both LBN and STUMP, due to the lack of strict diagnostic criteria. Based on such hypothesis, we aimed to define the risk of recurrence in LBN.

Study Design A systematic review and meta-analysis was performed by searching 4 electronic databases for all studies assessing the outcome of patients with “atypical leiomyoma” or LBN. The pooled absolute risk of recurrence was calculated. The included studies were subdivided into two subgroups based on the criteria used: “LBN + STUMP” or “LBN-only”.

Results Twelve studies with 433 patients were included. The pooled risk of recurrence was 5.5% overall. The funnel plot showed two cluster of studies which superimposed to the two subgroups. In the LBN + STUMP cluster/subgroup, the pooled risk of recurrence was 7.7%. In the LBN-only cluster/subgroup, the pooled risk of recurrence was 1.9%. Statistical heterogeneity was null in all analyses.

Conclusion Our results show a risk of recurrence of 1.9% for LBN; higher recurrence rates in older studies are likely due to the inclusion of STUMPs.

Molecular prognostication of uterine smooth muscle neoplasms: From CGH array to CINSARC signature and beyond

Uterine leiomyoma and leiomyosarcoma are located at the ends of the spectrum of smooth muscle lesions. Leiomyosarcoma belongs to the complex genomic sarcomas characterized by complex karyotypes. In contrast, leiomyoma, has a low level of chromosomal complexity. The analysis of genomic profiles of uterine smooth muscle tumors shows that genomic complexity, which is an expression of chromosomal instability, correlates with the metastatic potential and malignity of tumors: the more genetically complex a smooth muscle tumor is, the more malignant is its progression. In uterine tumors with uncertain malignant potential, the assessment of genomic index by CGH array, that is, counting the genomic complexity of a tumor, allows tumors with a risk of recurrence such as leiomyosarcomas to be distinguished from benign tumors like leiomyomas. The prognosis of leiomyosarcoma is poor and the most powerful prognostic factor so far is stage, as the histologic grade is not informative. In the quest to find efficient molecular prognostic factors, the transcriptomic signature CINSARC Nanocind, a mirror of chromosomic complexity and instability, outperforms stage, in both overall and recurrence-free survival. Genomic index and the CINSARC signature will contribute to improving diagnoses, therapeutic strategies, and randomization in future clinical trials. The biological understanding of the links between the CINSARC signature and metastatic mechanisms may lead to the development of new drugs. Furthermore, ctDNA is a promising new technique to detect residual disease and early recurrence.

Uterine smooth muscle tumours of uncertain malignant potential: single-centre experience and review of the literature

Introduction

Uterine smooth muscle tumours of uncertain malignant potential (STUMPs) are a rare histologically heterogeneous group of uterine smooth muscle tumours (SMTs). Their malignant potential and clinical differentiation between leiomyoma and leiomyosarcoma remain uncertain prior to surgical removal.

Aim of the study

To investigate the patients and tumour characteristics of patients with STUMPs and to propose algorithms for optimal diagnosis, treatment, and follow-up management.

Material and methods

This was a single-centre retrospective cohort study of all patients who underwent surgery for a preoperative diagnosis of uterine myoma at the University Hospital “Dr. Georgi Stranski”, Pleven, Bulgaria during a period of 33 months (from January 2013 until October 2015). Data were obtained from the medical history records. We performed descriptive analysis to characterise the patient population (e.g. demographics, age, contraceptive use, and complaints that led to the diagnosis) and the tumour characteristics. Last data were obtained prior May 2019.

Results

A total of 320 medical records were retrospectively evaluated. The preoperative diagnosis of myoma was confirmed in 279 of the cases (89.4%). In 27 (8.3%) cases the final histological result was completely different. In 14 (2.3%) a histological postoperative diagnosis of STUMP was identified. All 14 STUMP lesions were intramural with a median size of 7.5 cm (range 3.5 to 15 cm). The median age at diagnosis of STUMP was 45.4 years (range 36 to 52 years), and 92.9% (n = 13) of the patients were premenopausal. Ultrasound data of a rapidly growing myoma were a reason for diagnosis in only three patients (25%), whereas 92.9% of the patients (n = 13) presented with heavy menstrual bleeding with or without anaemia. After surgery, none of the patients with STUMP experienced a relapse of the disease within the median follow-up time of 48 months (R = 40-78).

Conclusions

STUMP tumours are rare tumours, predominantly diagnosed in premenopausal women. They define a group of patients with very good long-term prognosis. Therefore, longer follow-up is needed to allow for conclusions on recurrence rate and survival.

Deep venous thrombosis manifestation of common femoral vein leiomyoma

Deep vein thrombosis is a common clinical condition, with well-known risk factors. An unusual case of venous leiomyoma manifesting as a deep vein thrombosis in the left femoral vein of a 55-year-old man was managed successfully at our institution with anticoagulation, en-bloc excision and reconstruction of the femoral vein with spiral vein graft.

Clinical experience of uterine smooth muscle tumor of uncertain malignant potential in two gynecological centers: Oncological and obstetrical aspects

OBJECTIVES

To evaluate the clinical characteristics and obstetrical and oncological outcomes of patients with uterine smooth muscle tumors of uncertain malignant potential (STUMP) and analyze the risk factors for recurrence.

STUDY DESIGN

A retrospective cohort study was performed at two gynecological centers using data collected between January 2008 and August 2018. All the patients enrolled were diagnosed with STUMP and had been followed up for at least 6 months. The patients' characteristics, treatment methods, recurrence rate, and subsequent pregnancy outcomes were evaluated.

RESULTS

The mean age of the 62 patients was 36.1 ± 9.1 years (median 35, range 20-55 years) and mean follow-up duration was 36.3 ± 26.8 months (29.5, 6-130). All the patients were of premenopausal status. Fourteen patients (22.6 %) were initially treated by hysterectomy and 48 (77.4 %) by myomectomy. During the study period, three patients (4.8 %) experienced recurrence. However, there was no statistical difference between myomectomy and hysterectomy in terms of the rate of recurrence of STUMP or sarcoma, and all patients survived even after recurrence. Multivariate analysis revealed that a history of previous myomectomy was the sole independent risk factor for recurrence (odds ratio = 51.071; 95 % confidence interval = 2.743-950.726; p = 0.008). Subsequent pregnancies were successful in 10 of 19 women (52.6 %) who tried to conceive. Two of them had ongoing pregnancies at the time of last follow-up; the remaining eight women experienced a total of 14 subsequent pregnancies.

CONCLUSIONS

The recurrence rate of STUMP was similar between hysterectomy and myomectomy. Therefore, fertility sparing myomectomy can be considered in women diagnosed with STUMP with close monitoring.

Endocrine disruptor exposure during development increases incidence of uterine fibroids by altering DNA repair in myometrial stem cells

Despite the major negative impact uterine fibroids (UFs) have on female reproductive health, little is known about early events that initiate development of these tumors. Somatic fibroid-causing mutations in mediator complex subunit 12 (MED12), the most frequent genetic alterations in UFs (up to 85% of tumors), are implicated in transforming normal myometrial stem cells (MSCs) into tumor-forming cells, though the underlying mechanism(s) leading to these mutations remains unknown. It is well accepted that defective DNA repair increases the risk of acquiring tumor-driving mutations, though defects in DNA repair have not been explored in UF tumorigenesis. In the Eker rat UF model, a germline mutation in the Tsc2 tumor suppressor gene predisposes to UFs, which arise due to "second hits" in the normal allele of this gene. Risk for developing these tumors is significantly increased by early-life exposure to endocrine-disrupting chemicals (EDCs), suggesting increased UF penetrance is modulated by early drivers for these tumors. We analyzed DNA repair capacity using analyses of related gene and protein expression and DNA repair function in MSCs from adult rats exposed during uterine development to the model EDC diethylstilbestrol. Adult MSCs isolated from developmentally exposed rats demonstrated decreased DNA end-joining ability, higher levels of DNA damage, and impaired ability to repair DNA double-strand breaks relative to MSCs from age-matched, vehicle-exposed rats. These data suggest that early-life developmental EDC exposure alters these MSCs' ability to repair and reverse DNA damage, providing a driver for acquisition of mutations that may promote the development of these tumors in adult life.

Liquid Biopsy as a Tool for Differentiation of Leiomyomas and Sarcomas of Corpus Uteri

Utilization of liquid biopsy in the management of cancerous diseases is becoming more attractive. This method can overcome typical limitations of tissue biopsies, especially invasiveness, no repeatability, and the inability to monitor responses to medication during treatment as well as condition during follow-up. Liquid biopsy also provides greater possibility of early prediction of cancer presence. Corpus uteri mesenchymal tumors are comprised of benign variants, which are mostly leiomyomas, but also a heterogenous group of malignant sarcomas. Pre-surgical differentiation between these tumors is very difficult and the final description of tumor characteristics usually requires excision and histological examination. The leiomyomas and malignant leiomyosarcomas are especially difficult to distinguish and can, therefore, be easily misdiagnosed. Because of the very aggressive character of sarcomas, liquid biopsy based on early diagnosis and differentiation of these tumors would be extremely helpful. Moreover, after excision of the tumor, liquid biopsy can contribute to an increased knowledge of sarcoma behavior at the molecular level, especially on the formation of metastases which is still not well understood. In this review, we summarize the most important knowledge of mesenchymal uterine tumors, the possibilities and benefits of liquid biopsy utilization, the types of molecules and cells that can be analyzed with this approach, and the possibility of their isolation and capture. Finally, we review the typical abnormalities of leiomyomas and sarcomas that can be searched and analyzed in liquid biopsy samples with the final aim to pre-surgically differentiate between benign and malignant mesenchymal tumors.

Uterine smooth muscle tumor of uncertain malignant potential: fertility and clinical outcomes

Objective

In this study, we aimed to evaluate the clinicopathological features, obstetric, and oncological outcomes of patients diagnosed with a uterine smooth muscle tumors of uncertain malignant potential (STUMP).

Methods

A dual-institutional, database review was carried out to screen patients with STUMP who were treated with upfront surgery between January 2006 and December 2017. Data including age at the time of diagnosis, recurrence rate, disease-free survival, overall survival, and fertility outcomes were retrospectively analyzed.

Results

Fifty-seven patients with STUMPs were included in the study. The median age at the time of diagnosis was 42 (range, 16 to 75) years. The median follow-up was 57 (range, 16 to 125) months. Eight patients (14%) had recurrence during follow-up. Recurrent STUMPs were seen in seven patients and leiomyosarcoma after 14 months in one patient. Seven patients with a recurrent STUMP survived, while the remaining patient died. Recurrence rates were similar for women who underwent myomectomy and those who underwent hysterectomy. The presence of uterine localization of tumor (subserosal vs intramural-submucosal) statistically significantly affected recurrence rates (odds ratio=5.72; 95% confidence interval=1.349–24.290; p=0.018). Ten of 27 patients who underwent myomectomy for uterine myoma had fertility desire. Seven pregnancies were recorded.

Conclusions

Our study results suggest that fertility-sparing approaches are feasible in patients with STUMP, although recurrence may be seen.

Review of the literature laparoscopic surgery for metastatic hepatic leiomyosarcoma associated with smooth muscle tumor of uncertain malignant potential: Case report

Metastatic hepatic leiomyosarcoma is a rare malignant smooth muscle tumor. We report a case of metastatic hepatic leiomyosarcoma associated with smooth muscle tumor of uncertain malignant potential (STUMP). A 68-year-old female presented with a liver mass (60 mm × 40 mm, Segment 4). She underwent left salpingo-oophorectomy for an ovary tumor with STUMP in a broad ligament 6 years ago. Though FDG-PET showed obvious metabolically active foci, abnormal metabolically active foci other than the lesion were not detected. A malignant liver tumor was strongly suspected and laparoscopic partial liver resection was performed with vessel-sealing devices using the crush clamping method and Pringle maneuver. Immunohistochemical findings revealed metastatic liver leiomyosarcoma associated with STUMP in a broad ligament. This case is an extremely rare case of malignant transformation from primary STUMP to metastatic hepatic leiomyosarcoma. It provides important evidence regarding the treatment for metastatic hepatic leiomyosarcoma associated with STUMP.