Paediatric ovarian tumours and their associated cancer susceptibility syndromes

Biallelic MAD2L1BP (p31comet) mutation is associated with mosaic aneuploidy and juvenile granulosa cell tumors

MAD2L1BP-encoded p31comet mediates Trip13-dependent disassembly of Mad2- and Rev7-containing complexes and, through this antagonism, promotes timely spindle assembly checkpoint (SAC) silencing, faithful chromosome segregation, insulin signaling, and homology-directed repair (HDR) of DNA double-strand breaks. We identified a homozygous MAD2L1BP nonsense variant, R253*, in 2 siblings with microcephaly, epileptic encephalopathy, and juvenile granulosa cell tumors of ovary and testis. Patient-derived cells exhibited high-grade mosaic variegated aneuploidy, slowed-down proliferation, and instability of truncated p31comet mRNA and protein. Corresponding recombinant p31comet was defective in Trip13, Mad2, and Rev7 binding and unable to support SAC silencing or HDR. Furthermore, C-terminal truncation abrogated an identified interaction of p31comet with tp53. Another homozygous truncation, R227*, detected in an early-deceased patient with low-level aneuploidy, severe epileptic encephalopathy, and frequent blood glucose elevations, likely corresponds to complete loss of function, as in Mad2l1bp-/- mice. Thus, human mutations of p31comet are linked to aneuploidy and tumor predisposition.

Ovarian Masses in Children and Adolescents: A Review of the Literature with Emphasis on the Diagnostic Approach

Most abdominal masses in the pediatric population derive from the ovaries. Ovarian masses can occur in all ages, although their incidence, clinical presentation and histological distribution vary among different age groups. Children and adolescents may develop non-neoplastic ovarian lesions, such as functional cysts, endometrioma, torsion, abscess and lymphangioma as well as neoplasms, which are divided into germ cell, epithelial, sex-cord stromal and miscellaneous tumors. Germ cell tumors account for the majority of ovarian neoplasms in the pediatric population, while adults most frequently present with epithelial tumors. Mature teratoma is the most common ovarian neoplasm in children and adolescents, whereas dysgerminoma constitutes the most frequent ovarian malignancy. Clinical manifestations generally include abdominal pain, palpable mass, nausea/vomiting and endocrine alterations, such as menstrual abnormalities, precocious puberty and virilization. During the investigation of pediatric ovarian masses, the most important objective is to evaluate the likelihood of malignancy since the management of benign and malignant lesions is fundamentally different. The presence of solid components, large size and heterogenous appearance on transabdominal ultrasonography, magnetic resonance imaging and computed tomography indicate an increased risk of malignancy. Useful tumor markers that raise concern for ovarian cancer in children and adolescents include alpha-fetoprotein, lactate dehydrogenase, beta subunit of human chorionic gonadotropin, cancer antigen 125 and inhibin. However, their serum levels can neither confirm nor exclude malignancy. Management of pediatric ovarian masses needs to be curative and, when feasible, function-preserving and minimally invasive. Children and adolescents with an ovarian mass should be treated in specialized centers to avoid unnecessary oophorectomies and ensure the best possible outcome.

IDH Mutations Are Potentially the Intrinsic Genetic Link among the Multiple Neoplastic Lesions in Ollier Disease and Maffucci Syndrome: A Clinicopathologic Analysis from a Single Institute in Shanghai, China

BACKGROUND

This study aims to investigate isocitrate dehydrogenase gene mutations in patients with the non-hereditary skeletal disorders of Ollier disease and Maffucci syndrome, particularly in the extraosseous tumours.

METHODS

A total of 16 tumours from three patients with Ollier disease and three patients with Maffucci syndrome were collected. Sanger sequencing was applied to determine the hotspot mutations of IDH1 and IDH2 genes in multiple neoplastic tissues.

RESULTS

A majority of the tumours displayed an IDH1 mutation (p.R132C in 11 tumours including the paediatric ovarian tumour from one patient with Ollier disease, 4 cutaneous haemangiomas from three patients with Maffucci syndrome, 5 enchondromas and 1 chondrosarcoma; p.R132H in 2 cartilaginous tumours from one patient).

CONCLUSIONS

IDH1 mutations were demonstrated in multiple cartilaginous tumours and extraskeletal neoplasms in this case series. Specifically, identical IDH1 mutations were confirmed in the separate lesions of each patient. These results are in concordance with findings that have been reported. However, here, we additionally reported the first case of Ollier disease with an ovarian tumour, which harboured the identical IDH1 mutation with the corresponding cartilaginous tumour. We further provided evidence that IDH mutations are the potential genetic links among the multiple neoplastic lesions of Ollier disease and Maffucci syndrome.

Hereditary ovarian tumour syndromes: current update on genetics and imaging

Hereditary ovarian tumour syndromes are a diverse group of hereditary syndromes characterised by the development of specific histotypes of ovarian neoplasms. While BRCA syndromes are exclusively associated with high-grade serous carcinomas, patients with Lynch syndrome show a preponderance of endometrioid subtype of ovarian and endometrial carcinomas. Distinct non-epithelial phenotypes, such as sex cord stromal tumours with annular tubules, Sertoli-Leydig cell tumours, and small cell carcinoma of the hypercalcaemic type occur in patients with Peutz-Jeghers, DICER1, and rhabdoid tumour predisposition syndromes, respectively. Gorlin-Goltz syndrome is characterised by the development of bilateral, multiple ovarian fibromas in 14-24% of patients. Ovarian steroid cell tumours and broad ligament papillary cystadenomas are characteristically found in women with von Hippel-Lindau syndrome. Recent studies have allowed the characterisation of tumour genetics and associated oncological pathways that contribute to tumourigenesis. Implications of the diagnosis of these syndromes on screening, management, and prognosis are discussed.

Small-Cell Carcinoma of the Ovary, Hypercalcemic Type-Genetics, New Treatment Targets, and Current Management Guidelines

Small-cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare and highly aggressive ovarian malignancy. In almost all cases, it is associated with somatic and often germline pathogenic variants in SMARCA4, which encodes for the SMARCA4 protein (BRG1), a subunit of the SWI/SNF chromatin remodeling complex. Approximately 20% of human cancers possess pathogenic variants in at least one SWI/SNF subunit. Because of their role in regulating many important cellular processes including transcriptional control, DNA repair, differentiation, cell division, and DNA replication, SWI/SNF complexes with mutant subunits are thought to contribute to cancer initiation and progression. Fewer than 500 cases of SCCOHT have been reported in the literature and approximately 60% are associated with hypercalcemia. SCCOHT primarily affects females under 40 years of age who usually present with symptoms related to a pelvic mass. SCCOHT is an aggressive cancer, with long-term survival rates of 30% in early-stage cases. Although various treatment approaches have been proposed, there is no consensus on surveillance and therapeutic strategy. An international group of multidisciplinary clinicians and researchers recently formed the International SCCOHT Consortium to evaluate current knowledge and propose consensus surveillance and therapeutic recommendations, with the aim of improving outcomes. Here, we present an overview of the genetics of this cancer, provide updates on new treatment targets, and propose management guidelines for this challenging cancer.

Ovarian neoplasms of childhood

Ovarian neoplasms are rare in children. Although usually asymptomatic, they sometimes present with abdominal pain, abdominal distension or palpable mass. The distribution of neoplasms in the pediatric population is different from in adults; benign mature cystic teratoma is the most common ovarian tumor in children. Radiologists should be familiar with the variable sonographic, CT and MRI findings of ovarian neoplasms. Although the less frequently encountered ovarian malignancies cannot be reliably distinguished by imaging alone, it does play an important role in workup. This review discusses the imaging and relevant clinical manifestations of the more commonly encountered pediatric ovarian neoplasms.