Uterine leiomyomas in hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome can be identified through distinct clinical characteristics and typical morphology

Prospective Fumarate Hydratase Tumor Predisposition Syndrome Screening in Patients With Uterine Smooth Muscle Tumors: Age, Morphology, Fumarate Hydratase/S-(2-succino) Cysteine Immunohistochemistry, and Germline Testing

Fumarate hydratase tumor predisposition syndrome (FHTPS) is caused by germline fumarate hydratase (FH) pathogenic variants (PVs). Most women with FHTPS develop FH-deficient (FHD) uterine leiomyomas (ULs), which arise 10 to 15 years earlier than aggressive FHD-renal cell carcinoma. We evaluate a previously proposed FHTPS screening strategy for women with ULs. This 5-year, prospective and retrospective study performed FH and later S-(2-succino) cysteine immunohistochemistry (IHC) on all uterine smooth muscle (USM) tumors in patients 40 (later ≤30) years or younger and on all USM tumors with suggestive FHD morphology regardless of age. Patients with FHD tumors by IHC were referred to genetic counseling. Of 840 USM tumors, 112 FHD-tumors by IHC (13%) were identified, all with suggestive FHD-morphology; 44 patients (39%) underwent germline testing, and 15 harbored germline FH PVs (34.1% of germline tested, 13.4% of all FHD-tumors). While FHD tumors were seen across a wide age range (24 to 73 y), those with germline FH PVs were significantly younger (median 33 vs 44 years wild-type, P = 0.0032). Few (12.5%) patients ≥40 and no patients ≥50 had a germline FH PV, whereas a majority (60%) of patients <40 (86% of those <30) had a germline FH PV. We demonstrate that previously proposed resource-conscious screening involving morphology and IHC is effective for identifying women with FHTPS. We provide prospective data confirming patients presenting with FHD-ULs over age 50 are unlikely to harbor germline FH PVs and argue that for germline testing without consideration of other factors, a threshold of younger than 50 years may be appropriate.

Implications of Fumarate Hydratase Deficiency (FHD) and Cancer Risk: A Window into the Clinical and Oncological Implications of a Rare Disorder in Gynecology

Fumarate hydratase (FH) deficiency is a rare, yet impactful metabolic disorder caused by mutations in the FH gene, affecting the Krebs cycle, leading to the accumulation of fumarate and pseudohypoxic states. This metabolic shift promotes cell signaling alterations that can drive tumorigenesis, as heterozygous germline mutations in the FH gene, resulting in hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome. FH-deficient uterine leiomyomas show peculiar histological features that may lead to misdiagnosis STUMP (smooth muscle tumor of uncertain malignant potential) and uLMS (uterine leiomyosarcoma). Definitive diagnosis involves clinical evaluation, imaging, and histopathological examination, with immunohistochemistry for FH protein being a key diagnostic tool. Management of FH-deficient leiomyomas may involve conventional treatments like surgery and hormonal therapy but also requires careful monitoring and genetic counseling for associated malignancies. High-intensity focused ultrasound (HIFU) has emerged as a promising treatment option for fibroids, although long-term efficacy remains a concern also because of its inability to obtain tissue for a pathological diagnosis. Fumarate hydratase deficiency (FHD) represents a significant challenge in gynecologic oncology due to its association with an increased risk of hereditary leiomyomatosis and renal cell carcinoma. Nevertheless, to the best of our knowledge, there is a lack of studies demonstrating the potential role of FH deficiency in increased risk of leiomyosarcomatosus transformation. Early detection, genetic screening, and personalized treatment approaches are critical for improving patient outcomes. The aim of this review is to develop a narrative overview of the implications of FHD in gynecological diseases and its correlation with cancer risk. For the first time, this review offers an overview of the necessity for studies to address the possible correlation between FH deficiency and the risk of developing leiomyosarcoma, focusing on new perspectives that can be explored in the field of better FH deficiency knowledge and cancer risk.

Update on Cancer Screening in Children with Syndromes of Bone Lesions, Hereditary Leiomyomatosis and Renal Cell Carcinoma Syndrome, and Other Rare Syndromes

The management of children with syndromes associated with an increased risk of benign and malignant neoplasms is a complex challenge for health care professionals. The 2023 American Association for Cancer Research Childhood Cancer Predisposition Workshop provided updated consensus guidelines on cancer surveillance in these syndromes, aiming to improve early detection and intervention and reduce morbidity associated with such neoplasms. In this article, we review several of the rare conditions discussed in this workshop. Ollier disease and Maffucci syndrome are enchondromatoses (disorders featuring benign bone lesions) with up to 50% risk of malignancy, including chondrosarcoma. These patients require surveillance with baseline whole-body MRI and routine monitoring of potential malignant transformation of bony lesions. Hereditary multiple osteochondromas carry a lower risk of chondrosarcoma (<6%) but still require lifelong surveillance and baseline imaging. Related syndromes of benign bone lesions are also described. Hereditary leiomyomatosis and renal cell carcinoma syndrome, associated with fumarate hydratase pathogenic variants, is discussed in detail. Surveillance for renal cell carcinoma in pediatric age is recommended, as well as prompt intervention when a lesion is detected. Schinzel-Giedion syndrome and Rubinstein-Taybi syndrome are described for their associated malignancies and other complications, as well as expert consensus on the need for childhood cancer surveillance. Clinical recommendations, including imaging modalities and frequency of screenings, are proposed and are tailored to each syndrome's age-specific tumor risk profile. In all syndromes, patients and their families should be educated about the potential malignancy risk and advised to seek medical care for rapid growth of a mass, persistent pain, or other unexplained symptoms.

Clinical and molecular risk factors for repeat interventions due to symptomatic uterine leiomyomas

BACKGROUND

Repeat leiomyoma occurrence or even reintervention is common after myomectomy. Little is known about the factors related to repeat interventions.

OBJECTIVE

This study aimed to determine the frequency of leiomyoma-related reintervention after an initial laparoscopic or abdominal myomectomy and to analyze both clinical and molecular risk factors for reinterventions. Another objective was to define the frequency of clonally related tumors from repeat operations.

STUDY DESIGN

This retrospective cohort study included 234 women who had undergone laparoscopic or abdominal myomectomy in 2009 to 2014. Information on repeat leiomyoma-related interventions as well as on other clinical factors was collected from medical records after a median follow-up time of 11.4 years (range 7.9-13.8 years) after the index procedure. The effect of clinical risk factors on the risk of reintervention was analyzed by the Kaplan-Meier estimator and the Cox proportional hazards model. For molecular analyses, we examined the mutation profiles of 133 formalin-fixed paraffin-embedded leiomyoma samples from 33 patients with repeat operations. We screened the tumors for the 3 primary leiomyoma driver alterations-mediator complex subunit 12 mutations, high mobility group AT-hook 2 overexpression, and fumarate hydratase-deficiency-utilizing Sanger sequencing and immunohistochemistry. To further assess the clonal relationship of the tumors, we executed whole-exome sequencing for 52 leiomyomas from 21 patients who exhibited the same driver alteration in tumors obtained from multiple procedures.

RESULTS

Reintervention rate at 11.4 years after myomectomy was 20% (46/234). Number of leiomyomas removed at the index myomectomy was a risk factor (hazard ratio 1.21; 95% confidence interval 1.09-1.34). Age at index myomectomy (hazard ratio 0.94; 95% confidence interval 0.89-0.99) and postoperative parity (hazard ratio 0.23; 95% confidence interval 0.09-0.60) were protective factors. Molecular characterization of tumors from index and nonindex operations confirmed a clonal relationship of the tumors in 3/33 (9%) patients. None of the leiomyomas harboring a mediator complex subunit 12 mutation-the most common leiomyoma driver-were confirmed clonally related. Fumarate hydratase-deficiency was detected in repeat leiomyomas from 3/33 (9%) patients. All these patients harbored a germline fumarate hydratase mutation, which is distinctive for the hereditary leiomyomatosis and renal cell cancer syndrome. Finally, we identified 3 (3/33; 9%) patients with 2 tumors each displaying somatic mutations in a recently identified novel leiomyoma driver gene, YEATS domain-containing protein 4. All YEATS domain-containing protein 4 mutations were different and thus the tumors were not clonally related.

CONCLUSION

Our study shows that reintervention is common after surgical myomectomy. Uterine leiomyomas typically develop independently, but some share a clonal origin. Repeat leiomyoma occurrence may be due to genetic predisposition, such as a germline fumarate hydratase mutation. Distinct somatic YEATS domain-containing protein 4 mutations identified in multiple leiomyomas from the same patient indicate a possible role for YEATS domain-containing protein 4 in repeat leiomyomas.

High-intensity focused ultrasound ablation in the treatment of fumarate hydratase-deficient uterine leiomyoma

OBJECTIVE

This study aimed to explore the efficacy and safety of high-intensity focused ultrasound (HIFU) ablation for treating fumarate hydratase (FH)-deficient uterine leiomyomas.

METHOD

Ten patients with FH-deficient uterine leiomyomas treated with HIFU ablation at the Third Xiangya Hospital from July 2017 to January 2023 were enrolled in this study. The effectiveness and adverse effects of HIFU were analyzed.

RESULTS

The median age of the patients who received HIFU was 32.0 years (range: 28-41 years). Only 2 patients had solitary uterine leiomyomas, whereas the remaining 8 patients had multiple uterine leiomyomas. The median diameter of the largest myoma was 56 mm (range: 41-99 mm). Magnetic resonance imaging showed that the FH-deficient uterine leiomyomas of 8 patients presented as mixed intensity on T2WI, that of one patient was hypointense, and that of another patient was hyperintense on T2WI. All patients successfully underwent HIFU ablation in one session without severe adverse effects. The median nonperfusion volume ratio (NPVR) was 40% (30.0%-78.0%) after HIFU treatment. Four patients had NPVR ≥70%. At 3-month follow-up after HIFU ablation, the clinical symptoms of 5 of the 8 patients with symptoms before treatment were relieved. Six months after treatment, 4 of the 8 patients with symptoms were still in remission. All patients received reintervention by March 2024. The reintervention rates were 20%, 70%, and 90% at 12, 24, and 36 months, respectively, after HIFU ablation.

CONCLUSION

HIFU is a safe and feasible treatment for FH-deficient uterine leiomyomas, and most patients show effective results in the short term after treatment. However, the reintervention rates are high, and the long-term effects are limited.

Whole-Exome Sequencing Revealed a Pathogenic Germline Variant in the Fumarate Hydratase Gene, Leading to the Diagnosis of Hereditary Leiomyomatosis and Renal Cell Cancer

The diagnosis of hereditary skin tumors is difficult for "old" diagnostic tools such as immunohistochemistry. Whole-exome sequencing analysis as a "new" diagnostic tool enables us to make a final diagnosis in spite of unknown hereditary diseases in the past. Hereditary leiomyomatosis and renal cell cancer are autosomal dominant hereditary cancer syndromes characterized by uterine myomas, cutaneous leiomyomas, and aggressive renal cell cancer. The syndrome is associated with pathogenic germline variants in the fumarate hydratase gene. Herein, we demonstrate a pathogenic germline variant of the fumarate hydratase gene in a 60-year-old woman with multiple cutaneous leiomyomas, leading to the diagnosis of hereditary leiomyomatosis and renal cell cancer. Whole-exome sequencing analysis using genomic DNA extracted from peripheral blood leukocytes revealed one germline variant in the FH gene on chromosome 1 (c.290G>A, p.Gly97Asp). She received total hysterectomy due to uterine myoma, which strongly supported the diagnosis. No tumor was detected in her kidney by computed tomography and ultrasound examination. Genetic examination for the mutation of the fumarate hydratase gene is important in order to reach the correct diagnosis and to detect renal cancer at its early stage.

Uterine Leiomyomas with Specific Histology Features of Two Fumarate Hydratase/Succinate Dehydrogenase-Deficient Tumors: A Double Case Report

Background and Objectives: Mutations in succinate dehydrogenase (SDH) and fumarate hydratase (FH) give rise to various familial cancer syndromes, with these alterations being characteristic of certain types of histomorphologically specific leiomyomas that hold significant predictive value. Materials and Methods: This study presents two cases of uterine leiomyomas exhibiting rare histomorphological and genetic characteristics, which are crucial for prognosis and further treatment. Results: Distinct histopathological features such as marked nuclear atypia, intracellular eosinophilic globules, and abnormal intratumoral vessels raise suspicion for specific leiomyoma subtypes, which carry predictive significance for additional hereditary cancer syndromes. Immunohistochemical analysis confirmed FH/SDH deficiency in both patients, who underwent careful follow-up. Conclusions: This study describes two cases involving unusual leiomyomas, the histopathological characteristics of which may easily go unrecognized. These features hold predictive significance because their specific mutations point to additional hereditary cancer syndromes, highlighting the need for further examinations.

Fumarate Hydratase-Deficient Leiomyoma of the Uterine Corpus: Comparative Morphologic Analysis of Protein-Deficient Tumors With and Without Pathogenic Germline Fumarate Hydratase Gene Mutations

Deficiency of fumarate hydratase (FH) protein expression in uterine corpus leiomyomas may be attributable to either germline or somatic mutations of the FH gene, the former being definitional for the hereditary leiomyomatosis and renal cell cancer syndrome. The authors assess whether, using previously reported FH-associated morphologic features, FH protein-deficient uterine corpus leiomyomas associated with a pathogenic germline mutations of the FH gene (group 1) are distinguishable from FH protein-deficient uterine corpus leiomyomas without such mutations (and whose FH protein loss is presumed to be attributable to somatic/epigenetic inactivation or other unknown phenomena: group 2). Groups 1 and 2 were compared regarding a variety of clinicopathologic features, including 7 core "FH-associated" tumoral morphologic features: staghorn vasculature; alveolar-type edema; bizarre nuclei; chain-like tumor nuclei; hyaline cytoplasmic globules; prominent nucleoli, intranuclear inclusions, and perinucleolar halos; and prominent eosinophilic/fibrillary cytoplasm. Among 2418 patients diagnosed with uterine corpus leiomyoma during the study period, FH-associated morphologic features were reported in 1.5% (37 patients), and FH immunohistochemistry was performed in 29 (1.19%). Fourteen (48.27%) of the 29 patients showed FH protein deficiency by immunohistochemistry. Twelve patients underwent germline testing, of which 8 (66.7%) were classified as group 1 and 4 (33.3%) as group 2. FH protein-deficient tumors were larger (10.44 vs 4.08 cm, P  =  0.01) and associated with younger patients (42.05 vs 47.97, P  =  0.004) than 370 randomly selected uterine leiomyoma controls. Groups 1 and 2 showed no significant differences in patient age and tumor size. In group 1 tumors, the FH-associated morphologic features were generally present diffusely; all group 1 tumors displayed ≥5 FH-associated features, whereas all group 2 tumors displayed <5 FH-associated features (means 6.5  ±  0.53 vs 3.5  ±  1.00, P < 0.001). Notably, eosinophilic/fibrillary cytoplasm and alveolar-type edema were each significantly more prevalent in group 1 tumors than group 2 tumors (P  =  0.018 for both). No single morphologic feature was found to be completely sensitive and specific in making the distinction between group 1 and 2 tumors. Our findings suggest that groups 1 and 2 are unlikely to be morphologically distinguishable by individual morphologic features. Whether there is a combination of features that can reliably make this distinction is unclear and will require additional studies with larger cohorts.

Inherited mutations affecting the SRCAP complex are central in moderate-penetrance predisposition to uterine leiomyomas

Uterine leiomyomas (ULs) are benign smooth muscle tumors that are common in premenopausal women. Somatic alterations in MED12, HMGA2, FH, genes encoding subunits of the SRCAP complex, and genes involved in Cullin 3-RING E3 ligase neddylation are mutually exclusive UL drivers. Established predisposition genes explain only partially the estimated heritability of leiomyomas. Here, we examined loss-of-function variants across 18,899 genes in a cohort of 233,614 White European women, revealing variants in four genes encoding SRCAP complex subunits (YEATS4, ZNHIT1, DMAP1, and ACTL6A) with a significant association to ULs, and YEATS4 and ZNHIT1 strikingly rank first and second, respectively. Positive mutation status was also associated with younger age at diagnosis and hysterectomy. Moderate-penetrance UL risk was largely attributed to rare non-synonymous mutations affecting the SRCAP complex. To examine this disease phenotype more closely, we set out to identify inherited mutations affecting the SRCAP complex in our in-house sample collection of Finnish individuals with ULs (n = 860). We detected one individual with an ACTL6A splice-site mutation, two individuals with a YEATS4 missense mutation, and four individuals with DMAP1 mutations: one splice-site, one nonsense, and two missense variants. These individuals had large and/or multiple ULs, were often diagnosed at an early age, and many had family history of ULs. When a somatic second hit was found, ACTL6A and DMAP1 were silenced in tumors by somatic mutation and YEATS4 by promoter hypermethylation. Decreased H2A.Z staining was observed in the tumors, providing further evidence for the pathogenic nature of the germline mutations. Our results establish inactivation of genes encoding SRCAP complex subunits as a central contributor to moderate-penetrance UL predisposition.