Clinicopathological analysis of 22 Müllerian adenosarcomas and the sequencing of DICER1 mutation

BACKGROUND

Müllerian adenosarcoma, a rare malignancy, presents diagnostic and therapeutic challenges. In this study, we conducted an analysis of the clinicopathological characteristics of 22 adenosarcomas, with a particular focus on screening for DICER1 hot mutations.

METHODS

The cohort consisted of patients with adenosarcoma who were registered at the West China Second Hospital between the years 2020 and June 2022. Sanger sequencing was employed to screen for somatic Hotspot mutations in the RNase IIIb domain of DICER1 in the 22 adenosarcomas.

RESULTS

Only one patient exhibited a DICER1 mutation that was not a DICER1 Hotspot mutation. Among the 22 patients, all underwent total hysterectomy with bilateral salpingo-oophorectomy, and 14 out of these 22 patients received adjuvant treatment.

CONCLUSION

In summary, our study of 22 Müllerian adenosarcomas focused on the clinicopathological features and the presence of DICER1 Hotspot mutations. Although our findings did not reveal any DICER1 mutations in the studied samples, this negative result provides valuable information for the field by narrowing down the genetic landscape of adenosarcomas and highlighting the need for further research into alternative molecular pathways driving this malignancy.

Histopathologic "Evolution" in Pediatric Primary Intracranial High-Grade Sarcoma - a Key that Unlocked the Correct Diagnosis

Central nervous system (CNS) tumors are the second most common in the pediatric age group, accounting for 3.5% of overall mortality. The 2021 World Health Organization (WHO) classification of pediatric CNS tumors has given insight into their molecular biology. Correct diagnosis of high-grade intracranial sarcomas is a well-known challenge because of their histopathological variation, presence of heterologous elements, and haphazard pattern of growth. We present a case of a 13-year-old female with a right-sided frontal hemorrhagic mass. Pathological work-up revealed an intra-cranial high-grade sarcoma, not otherwise specified (NOS). Despite receiving chemo-radiation, the lesion recurred after 9 months. This time, the sarcoma had evolved, showing distinct focal rhabdomyoblastic differentiation. Next-generation sequencing (NGS) based assay revealed variants p.E1705V, p.Y1417Ter in DICER1, and other mutations in KRAS and TP53 genes. The lesion was then diagnosed as spindle cell sarcoma with rhabdomyosarcoma-like features, DICER1 mutant. We propose that upfront molecular studies in pediatric undifferentiated high-grade sarcomas are indicated for precise diagnosis and classification.

DICER1 Mutation in Recurrent Ovarian Sertoli-Leydig Cell Tumor: A Case Report

BACKGROUND

DICER1 mutation has been linked to development of Sertoli-Leydig cell tumor and cystic nephroma, among other neoplasms.

CASE

We present a unique case of recurrent ovarian Sertoli-Leydig cell tumor in a pediatric patient with a known DICER1 mutation and history of cystic nephroma. She underwent surgical staging and adjuvant chemotherapy, and her recurrences have been treated with chemotherapy, whole-abdomen radiation therapy, and further surgical debulking.

CONCLUSION

This report adds to the small body of evidence about this rare but unexpectedly highly aggressive tumor, especially in the recurrent setting, and reminds the reader of the importance of cancer diagnosis in this population.

Recurrent gynandroblastoma of the ovary with germline DICER1 mutation: A case report and review of the literature

Sex cord-stromal tumors (SCSTs) are ovarian tumors that generally present with an adnexal mass and signs/symptoms of hormone excess. Gynandroblastoma is a rare subtype of SCST with a combination of female and male sex cord differentiation. These tumors typically present in premenopausal women and are diagnosed at early stages with benign clinical courses. Here, we present a rare case of recurrent gynandroblastoma in a premenopausal woman with a DICER1 germline mutation. The patient was referred to our clinic for new symptoms of hormonal imbalance with a history of ovarian juvenile granulosa cell tumor (JGCT). Evaluation revealed a 5x5cm complex right adnexal mass and rising inhibin B. Patient underwent total abdominal hysterectomy with right salpingo-oophorectomy, omentectomy and right pelvic and para-aortic lymphadenectomy. Pathology showed a right ovarian gynandroblastoma. Somatic biallelic mutations in the RNase IIIb domain of DICER1 were identified; a 23-gene germline panel confirmed a germline DICER1 pathogenic variant. Cascade testing of her children documented that both daughters inherited the pathogenic variant. Testing for DICER1 mutations has important implications for individual and familial tumor risk assessment given what we know about DICER1 mutation and increased childhood cancer risk.

Prevalence and Spectrum of DICER1 Mutations in Adult-onset Thyroid Nodules with Indeterminate Cytology

CONTEXT

DICER1 mutations are found in multinodular goiter and differentiated thyroid carcinoma in children, and can be a manifestation of DICER1 syndrome, but the prevalence of DICER1 mutations and their significance in adult-onset thyroid nodules is unknown.

OBJECTIVE

Determine (1) the prevalence of DICER1 hotspot mutations in thyroid nodules; (2) the frequency of a second DICER1 pathogenic variant in thyroid nodules with DICER1 hotspot mutations; (3) the prevalence of other thyroid cancer driver mutations in thyroid nodules with and without DICER1 hotspot mutations.

METHODS

Population-based study of 14 993 consecutive fine needle aspiration biopsies of thyroid nodules evaluated by ThyroSeq v3. From 214 DICER1 hotspot-positive cases, we selected 61, matched to DICER1 hotspot-negative nodules. We performed full sequencing of all exons and exon-intron boundaries of DICER1.

SETTING

Commercial and university-based laboratories in the United States and Canada.

RESULTS

Among 14 993 thyroid nodules, 214 (1.4%) revealed a DICER1 hotspot mutation. A second pathogenic/likely pathogenic variant in DICER1 was found in 45/59 (76%) DICER1 hotspot-positive nodules studied while no other DICER1 variant was identified in the DICER1 hotspot-negative group by full DICER1 sequencing. Other alterations in thyroid-related genes were significantly more frequent in DICER1 hotspot-negative nodules (32/61) than in DICER1 hotspot--positive nodules (4/59) (P < .0001).

CONCLUSION

DICER1 alterations occur in a proportion of adult thyroid nodules and appear mutually exclusive with alterations in other thyroid cancer-related genes. DICER1 hotspot mutations occur with a second hit in most cases and could suggest occult DICER1 syndrome in adults with thyroid nodules.

Prevalence of Pathogenic Germline DICER1 Variants in Young Individuals Thyroidectomised Due to Goitre - A National Danish Cohort

INTRODUCTION

DICER1 syndrome encompasses a variety of benign and malignant manifestations including multinodular goitre, which is the most common manifestation among individuals carrying pathogenic DICER1 variants. This is the first study estimating the prevalence of pathogenic DICER1 variants in young individuals with multinodular goitre.

METHODS

Danish individuals diagnosed with nodular goitre based on thyroidectomy samples in 2001-2016 with the age limit at time of operation being ≤ 25 years were offered germline DICER1 gene testing.

RESULTS

Six of 46 individuals, 13% (CI [3.3;22.7], p <0.05), diagnosed with nodular goitre on the basis of thyroidectomy samples under the age of 25 years had pathogenic germline variants in DICER1. They were found in different pathoanatomical nodular goitre cohorts i.e. nodular goitre (n=2), colloid nodular goitre (n=3) and hyperplastic nodular goitre (n=1).

CONCLUSIONS

We recommend referral of patients thyroidectomised due to goitre aged <21 years and patients thyroidectomised due to goitre aged <25 years with a family history of goitre to genetic counselling. Patients of all ages thyroidectomised due to goitre, who are affected by another DICER1 manifestation should be referred to genetic counselling.

Somatic tumour testing establishes that bilateral DICER1-associated ovarian Sertoli-Leydig cell tumours represent independent primary neoplasms

AIMS

Sertoli-Leydig cell tumours (SLCTs) are rare ovarian neoplasms that are commonly associated with somatic or germline DICER1 mutations, especially when of the moderately or poorly differentiated type. A large majority are unilateral, but bilateral neoplasms have been reported, sometimes in the context of germline DICER1 mutations (DICER1 syndrome). It is currently unknown whether these represent independent neoplasms or metastasis from one ovary to the other and we aimed to elucidate this.

METHODS AND RESULTS

We report three cases of bilateral ovarian SLCT (all in patients with DICER1 syndrome) and review all reported cases of bilateral neoplasms. In the three cases (all moderately or poorly differentiated neoplasms), the time interval between the discovery of the tumours in each ovary ranged from 2.7 years to 6 years. In all cases, different DICER1 somatic hotspot mutations within the two tumours provided definitive proof that they represent independent neoplasms; this may be important clinically. Our literature review revealed that, when this information was available, all patients with bilateral SLCT had a germline DICER1 mutation.

CONCLUSIONS

Bilateral ovarian SLCTs represent independent rather than metastatic neoplasms, and essentially always occur in the context of DICER1 syndrome.

A rare malignant thyroid carcinosarcoma with aggressive behavior and DICER1 gene mutation: a case report with literature review

Background

Malignant biphasic tumor also known as carcinosarcoma is an uncommon neoplasm that is composed of both malignant epithelial and mesenchymal components. Most reported cases of carcinosarcoma affect the female genital tract; however, other sites including head and neck, lung, and breast have been described. Carcinosarcoma of the thyroid is an extremely rare and aggressive malignancy with an ominous clinical course similar to anaplastic carcinoma.

Case presentation

We report a case of a 45-year-old female who was found to have a biphasic thyroid carcinosarcoma. Her clinical course declined significantly shortly after she underwent a total thyroidectomy and she developed distant metastases to the lungs. Histopathological features of the primary and metastatic tumor were identical. The tumor is composed of an intimately intermixed epithelial component of poorly differentiated follicular thyroid carcinoma and a spindle cell sarcoma with rhabdomyosarcoma differentiation. Molecular analysis using a next-generation sequencing based assay revealed a DICER1 (E1705K) point mutation in neoplastic cells.

Conclusion

To our knowledge, the E1705K point mutation within the DICER1 gene is the first reported mutation in carcinosarcoma of the thyroid. A comprehensive review of the relevant literature is also included for discussion.