Primary pineal rhabdomyosarcoma successfully treated by high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation: case report

A rare presentation of a bilateral intracranial parameningeal embryonal rhabdomyosarcoma mimicking vestibular schwannoma in a two-year-old child: a case report

Intracranial parameningeal rhabdomyosarcomas are rare, aggressive, rapidly progressive paediatric malignancies that carry a poor prognosis. The authors report a case of a 2-year-old boy who initially presented with a left facial palsy, ataxia and, shortly after, bloody otorrhoea. MRI imaging was initially suggestive of a vestibular schwannoma. However, there was rapid progression of symptoms and further MRI imaging showed very rapid increase in tumour size with mass effect and development of a similar tumour on the contralateral side. A histological diagnosis of bilateral parameningeal embryonal rhabdomyosarcoma was made. Despite treatment, progression led to hydrocephalus and diffuse leptomeningeal disease, from which the patient did not survive. Few intracranial parameningeal rhabdomyosarcomas have previously been reported and these report similar presenting symptoms and rapid disease progression. However, this is the first reported case of a bilateral intracranial parameningeal embryonal rhabdomyosarcoma which, on initial presentation and imaging, appeared to mimic a vestibular schwannoma.

Primary Pineal Rhabdomyosarcoma: A Rare Case

Primary pineal rhabdomyosarcoma (RMS) is extremely rare, and only three cases have been reported so far. Here, we report a case of 12-year-old male who presented with complaints of diplopia and diminution of vision since 15 days. He also had left-sided facial paresis. Magnetic resonance imaging brain revealed a space-occupying lesion in the region of pineal gland. The patient underwent midline suboccipital craniectomy with excision of tumor. Microscopic examination revealed a highly cellular tumor with areas showing small round cells admixed with cells having abundant eosinophilic cytoplasm resembling rhabdomyoblasts and multinucleated giant cells. Differential diagnoses of pineal anlage tumor and primary RMS were considered. The tumor cells were positive for desmin while being negative for synaptophysin and glial fibrillary acidic protein. Myogenin was used to confirm the diagnosis of RMS, which showed focal nuclear positivity. INI1 was retained. All the markers for germ cell tumors were negative.

Treatment strategy and long-term outcomes of primary intracranial rhabdomyosarcoma: a single-institution experience and systematic review

OBJECTIVE

Primary intracranial rhabdomyosarcoma (PIRMS) is rare, and the effects of the treatment strategy on overall survival (OS) are unclear. This study aimed to evaluate risk factors pertinent to OS and to propose an optimal treatment strategy.

METHODS

Clinical data of patients with PIRMS treated at Beijing Tiantan Hospital and from the English-language literature between 1946 and 2018 were reviewed. A literature review was performed via Ovid, MEDLINE, Embase, PubMed, Web of Science, and Cochrane databases using the terms "rhabdomyosarcoma," "intracranial," "cerebral," and "brain." Previously published data were processed and used according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

There were 8 males (66.7%) and 4 females with PIRMS at our institution, with a mean age of 24.3 years. Gross-total resection was achieved in 4 patients (33.3%), and adjuvant radiation and chemotherapy were administered in 5 (45.5%) and 3 (27.3%) patients, respectively. After a mean follow-up period of 13.7 months, all patients developed local-regional recurrence and died of the disease. Twenty-nine cases (14 female and 15 male) were reported in the literature with a median age of 9.0 years. After a mean follow-up duration of 18.6 months, 13 patients (44.8%) developed recurrences, 7 patients (24.1%) had extracranial metastasis, and 14 patients (48.3%) died. In the pooled cases, adjuvant radiation (hazard ratio [HR] 0.089, 95% confidence interval [CI] 0.027-0.288, p < 0.001) and age < 10 years (HR 0.227, 95% CI 0.077-0.666, p = 0.007) were independent predictors of good local-regional progression-free survival (LR-PFS). Adjuvant radiation therapy (HR 0.301, 95% CI 0.110-0.828, p = 0.020) and age < 10 years (HR 0.359, 95% CI 0.131-0.983, p = 0.046) were significant predictors for favorable OS in the multivariate model.

CONCLUSIONS

Due to the rarity of the disease, a poor outcome of PIRMS was demonstrated based on the pooled cohort. Use of radiation was associated with improved outcomes and should be considered to improve OS/LR-PFS. Further study is required to identify the optimal treatment regimen.Systematic review no.: CRD42019121249 (crd.york.ac.uk/PROSPERO/).

Two cases of primary supratentorial intracranial rhabdomyosarcoma with DICER1 mutation which may belong to a "spindle cell sarcoma with rhabdomyosarcoma-like feature, DICER1 mutant"

Rhabdomyosarcoma is the most common soft-tissue sarcoma affecting children and adolescents. It is defined as a malignant neoplasm characterized by morphologic, immunohistochemical, ultrastructural, or molecular genetic evidence of primary skeletal muscle differentiation, usually in the absence of any other pattern of differentiation. Primary intracranial rhabdomyosarcoma (PIRMS) is an extremely rare neoplasm, with only 60 cases reported in the literature, and generally has poor prognosis with an overall survival of only 9.1 months. The DICER1 gene encodes an RNA endoribonuclease that plays a key role in gene expression regulation through the production of small RNAs. Herein, we report two cases of PIRMS with somatic DICER1 mutation showing morphological and immunohistochemical evidence of primary skeletal muscle differentiation; the two cases share common clinical features, including young age, supratentorial tumor, and onset of intratumoral bleeding. Although methylation profiling was not performed, both cases shared clinical and pathological characteristics in common with recently proposed methylation entity "spindle cell sarcoma with rhabdomyosarcoma-like features, DICER1 mutant (SCS-RMSlike-DICER1)''. Our cases provide further evidence of the link between primary intracranial sarcoma and DICER1 mutation which may form a distinct entity.

Primary CNS Alveolar Rhabdomyosarcoma: Importance of Epigenetic and Transcriptomic Assays for Accurate Diagnosis

We present the case of a 22-year-old woman who developed increasing headaches, nausea, and vomiting. Imaging identified a 3 × 3 cm heterogeneously enhancing cystic mass in the posterior III ventricular/pineal region. Pathology review of the initial lesion revealed a highly malignant spindle cell neoplasm composed of round to mostly oval elongated cells with relatively small amounts of cytoplasm arranged in sheets and fascicles with focal storiform pattern. Whole genome methylation analysis through unsupervised clustering with data generated from other primary intracranial tumors and peripheral sarcomas was performed at the German Cancer Research Center (DKFZ) and classified the tumor with the group of alveolar rhabdomyosarcomas (ARMS). Further RNA sequencing revealed an in frame PAX3 (EX 7)-NCOA2 (EX12) fusion confirming the diagnosis. This is the first evidence of occurrence of PAX3-NCOA2 in primary CNS ARMS.