Objective Responses in Metastatic Pleomorphic Rhabdomyosarcoma Treated with Combination of Doxorubicin and Pembrolizumab: A Case Series

Introduction

Pleomorphic rhabdomyosarcoma is a rare subtype of rhabdomyosarcoma, a soft tissue sarcoma with skeletal muscle differentiation. Although rhabdomyosarcoma is typically seen in the pediatric population, the pleomorphic variant most frequently presents in adulthood and is characteristically aggressive with no currently established treatment regimen in the setting of metastatic disease. There has been growing interest in the application of immune checkpoint inhibitors alongside conventional chemotherapeutic agents in the treatment of pleomorphic rhabdomyosarcoma.

Case Presentation

In the present case series, we report 2 patients with metastatic pleomorphic rhabdomyosarcoma treated with combination doxorubicin and pembrolizumab who had confirmed objective responses. Of note, these 2 patients had variable PD-L1 status - negative and low positive. Duration of treatment response was notable at 14 months and 9 months, respectively, with the first patient remaining on maintenance pembrolizumab therapy and the second patient subsequently achieving complete response with third-line trabectedin. Both patients are currently undergoing routine interval imaging with no evidence of disease at this time.

Conclusion

This report highlights and discusses the potential role of PD-1 blockade in the treatment of pleomorphic rhabdomyosarcoma and also discusses burgeoning immunological data that may explain the clinical responses seen in these 2 cases.

Complete loss of TP53 and RB1 is associated with complex genome and low immune infiltrate in pleomorphic rhabdomyosarcoma

Rhabdomyosarcoma accounts for roughly 1% of adult sarcomas, with pleomorphic rhabdomyosarcoma (PRMS) as the most common subtype. Survival outcomes remain poor for patients with PRMS, and little is known about the molecular drivers of this disease. To better characterize PRMS, we performed a broad array of genomic and immunostaining analyses on 25 patient samples. In terms of gene expression and methylation, PRMS clustered more closely with other complex karyotype sarcomas than with pediatric alveolar and embryonal rhabdomyosarcoma. Immune infiltrate levels in PRMS were among the highest observed in multiple sarcoma types and contrasted with low levels in other rhabdomyosarcoma subtypes. Lower immune infiltrate was associated with complete loss of both TP53 and RB1. This comprehensive characterization of the genetic, epigenetic, and immune landscape of PRMS provides a roadmap for improved prognostications and therapeutic exploration.

Diagnosis and treatment of pleomorphic rhabdomyosarcoma of the uterus: a rare case report and review of the literature

Pleomorphic rhabdomyosarcomas of the uterus (PRMSu) is a rare malignant tumor of the female genital tract. Accurate diagnosis and effective treatment of PRMSu are important. We report an 81-year-old woman who was diagnosed with PRMSu. She had an extremely unusual presentation of secondary dyspnea because of an extremely large uterus (26.0 cm). Pelvic magnetic resonance imaging showed rare severe enlargement and intrauterine filling with tumor tissue, and she was initially diagnosed with uterine leiomyosarcoma. The patient underwent hysterectomy, as well as bilateral salpingo-oophorectomy and omentectomy, and was finally confirmed as having PRMSu by histopathology combined with immunohistochemistry. We performed a systematic review of the literature between 1982 and 2020 and focused on different treatment strategies and prognosis of PRMSu. A retrospective review of 28 cases was conducted and survival analysis was estimated by using the Kaplan–Meier method. We found that the accuracy of diagnosis of PRMSu completely depends on histopathology and immunohistochemistry because of no special clinical symptoms, no sensitive tumor markers, and no special imaging findings. Although there is no standardized approach for treating this rare disease, the treatment strategy of a surgical operation combined with adjuvant chemotherapy appears to be the best choice.

Pleomorphic rhabdomyosarcoma on the chest wall which infiltrated intercostal muscles: A case report

INTRODUCTION

Rhabdomyosarcoma (RMS) is the malignant tumor of skeletal muscles that origin from rhabdomyoblast. RMS is the most common soft tissue tumor in children, but this is a sporadic condition in adults and only 1% of any solid malignancies of an adult. The most prevalent subtype of RMS in an adult is a pleomorphic type.

PRESENTATION OF CASE

We reported a case of a 57 years old woman with swelling on the left chest with pain for three years. Physical examination revealed swelling on the left chest with solid consistency and immobile. The thorax CT-scan with IV contrast suspicious soft tissue tumor on the anteromedial of the left chest wall that stuck to the left lung.

DISCUSSION

Histopathological examination confirmed the pleomorphic subtype of rhabdomyosarcoma. The interdisciplinary idea was reported to be superior to a single therapeutic modality. The patient underwent an incisional biopsy.

CONCLUSION

This is a case of pleomorphic rhabdomyosarcoma diagnosed base on histopathology from an incisional biopsy, and IHC performed wide excision gave satisfactory results.

Pleomorphic rhabdomyosarcoma of the spermatic cord and a secondary hydrocele testis: A case report

BACKGROUND

Pleomorphic rhabdomyosarcoma (RMS) of the spermatic cord is a group of rare neoplasms, and a secondary hydrocele testis occasionally occurs. The misdiagnosis of paratesticular mass may lead to a therapeutic delay.

CASE SUMMARY

A 79-year-old man presented to our clinic complaining of a 1-mo history of painless scrotal swelling. Physical examination revealed approximately a 15 cm × 10 cm × 5 cm inguinal mass with limited mobility. Contrast-enhanced magnetic resonance imaging showed a hydrocele testis, several enlarged inguinal lymph nodes, and a heterogeneously enhanced lesion with a relatively well-defined margin in the left inguinal region. Due to the imaging findings, he was diagnosed with pleomorphic RMS and received a wide resection of the mass, an inguinal incision with a high section of the left spermatic cord, and a left radical orchiectomy. He experienced local relapse 1 mo postoperatively and received radiotherapy and anlotinib hydrochloride-based immunotherapy as adjuvant therapy. The patient died 3 mo after the surgery.

CONCLUSION

The optimal interventions for advanced-stage pleomorphic RMS patients should be investigated by more preclinical studies and clinical trials. Physicians need to be aware of the occurrence of pleomorphic RMS in unusual locations, especially when accompanied by a hydrocele testis.

High-grade pleomorphic rhabdomyosarcoma in a 60-year-old male: a case report and review of the literature

Rhabdomyosarcoma is an aggressive malignant soft-tissue sarcoma that develop from undifferentiated mesenchymal cells. Less than 1% of all adult solid malignant cancers are sarcomas, and RMSs represent less than 2–5% of adult sarcomas.   RMS is divided into three main subtypes: Embryonal, alveolar and pleomorphic RMS (PRMS).   Most common subtype in adults is PRMS. Most common primary sites are extremities, trunk wall, and genitourinary organs. Metastasis are often found at diagnosis. 5-year overall survival rates were reported in the Surveillance, Epidemiology, and End Results database (SEER) to be 63% for pediatric patients and 27% for adults. Given the rarity of the adult PRMS, variation in its clinical presentation, characteristics of the tumor itself and the prognosis; there are very limited data available to guide the management of adults with PRMS. Herein we present a case report of pleomorphic rhabdomyosarcoma of the right thigh in a 60-year-old male who achieved a long-term survival (30 months) which was accomplished by multimodality treatment including surgery, radiotherapy, and chemotherapy.   

Molecular characterization of a bladder pleomorphic rhabdomyosarcoma in an adult patient

Pleomorphic rhabdomyosarcoma (PRMS) is a rare but highly aggressive soft tissue tumor, accounting for 3% of soft tissue sarcomas. PRMS is the most frequent subtype of RMS in adulthood and it is mainly located in the large muscles of the extremities, particularly the lower limbs and the trunk, more rarely in other locations especially in the bladder. At our knowledge, only six cases of adult pleomorphic rhabdomyosarcoma of the bladder have been reported in the literature. In this study, we report a case of PRMS of bladder with a very poor prognosis. In fact, the patient died a month after surgery. The tumor was characterized by poorly differentiated, medium-sized sometimes rhabdoid cells, mixed with large-sized and pleomorphic elements with evident anisonucleosis, and with large areas of necrosis. We used an extensive immunohistochemical panel to exclude other tumors much more frequently reported at this site. The positivity for myogenic markers such as actin, desmin, myogenin and MyoD1 allowed the correct diagnosis. Furthermore, since preliminary studies highlighted a series of specific molecular alterations in PMRS cell lines, we analyzed a panel of specific mutations and gene rearrangements by RT-PCR and FISH methods. We showed a copy gains of CCND1 and MALT genes in our samples, suggesting an accurate molecular characterization of PRMS to establish a better management of patients and new therapeutic opportunities.

Pleomorphic rhabdomyosarcoma of the liver in an adult: a rare case report

BACKGROUND

Rhabdomyosarcoma (RMS), a malignant neoplasm that normally differentiates to form striated muscle, is the most common type of childhood soft tissue sarcoma. However, it infrequently occurs in adults and is uncommon in the liver. We herein report a case of RMS of the liver in an adult.

CASE PRESENTATION

A 73-year-old woman was admitted to our institution for investigation of a hepatic mass. She had been followed for primary biliary cirrhosis for the past 20 years. A contrast-enhanced computed tomography scan of the abdomen showed a 12- × 10-cm heterogeneous low-density mass lesion containing cystic and solid components. A percutaneous liver biopsy was performed, and poorly differentiated cancer containing an RMS cell-like component was observed. The patient was diagnosed with RMS of the liver, and open surgery with right hepatic lobectomy was performed. Histopathological examination confirmed a diagnosis of pleomorphic RMS of the liver. The patient died of rapid progression of the tumor 6 months after the operation.

CONCLUSIONS

The tumor site in the present case is rare. The details of this case add to the current evidence base regarding establishment of the standard diagnosis and treatment of this rare condition. We recommend consideration of RMS as a differential diagnosis for hepatic tumors.

Clinicopathologic features of 300 rhabdomyosarcomas with emphasis upon differential expression of skeletal muscle specific markers in the various subtypes: A single institutional experience

The present study was aimed at evaluating clinicopathologic and immunohistochemical (IHC) features of 300 rhabdomyosarcomas (RMSs), including differential IHC expression and prognostic value of myogenin and MyoD1 across various subtypes of RMSs. IHC expression of myogenin and MyoD1 was graded on the basis of percentage of tumor cells displaying positive intranuclear immunostaining i.e. grade 1 (1-25%); grade 2 (26-50%); grade 3 (51-76%) and grade 4 (76-100%).Clinical follow-up was available in 238 (79.3%) patients. Various clinicopathologic parameters were correlated with 3-year disease free survival (DFS) and overall survival (OS). There were 140 cases (46.7%) of alveolar RMS (ARMS), 90 of embryonal RMS (ERMS) (30%), 61 (20.3%) of spindle cell/sclerosing RMS and 9 cases (3%) of pleomorphic RMS. Most cases, barring pleomorphic RMSs, occurred in the first two decades (228 cases) (76%), frequently in males, in the head and neck region (126) (42%). By immunohistochemistry, desmin was positive in 292/299 (97.6%) tumors; myogenin in 238/267 (89.1%) and MyoD1 in 192/266 (72.2%) tumors. High myogenin expression (in ≥51% positive tumor cells) was significantly associated with ARMSs (95/121, 78.5%), as compared to other subtypes (48/117, 41%) (p value < 0.001). High MyoD1 expression (≥51% tumor cells) was seen in more cases of pure sclerosing, combined with spindle cell/sclerosing RMSs (10/10, 100%), as compared to the other subtypes (91/141, 67.4%) (p = 0.032). There was no significant difference between high myogenin expression and clinical outcomes. Patients without metastasis and harbouring tumors, measuring ≤5 cm showed a significant increase in OS, with p values = 0.01 and <0.001, respectively. ARMS was the most frequent subtype. There was a significant association between high myogenin expression and ARMSs and high MyoD1 expression and spindle cell/sclerosing RMSs. High myogenin expression did not correlate with clinical outcomes. Patients with smaller sized tumors and without metastasis had significantly better clinical outcomes.

Primary rhabdomyosarcoma of the distal femoral diaphysis: a case report and review of the literature

Primary rhabdomyosarcoma of the bone is an extremely rare condition with few examples reported in the literature. We present the case of a 34-year-old male who presented with a lesion in the distal femur with initial imaging features consistent with Ewing sarcoma. Histologically, the lesion consisted of atypical pleomorphic polygonal rhabdomyoblasts demonstrating focal desmin and myogenin expression. A diagnosis of pleomorphic rhabdomyosarcoma was rendered. Despite systemic treatment and surgery, this patient experienced a rapidly progressive disease course. We believe this is only the second report in the orthopedic literature of a case of primary pleomorphic rhabdomyosarcoma of the bone. The key imaging, pathologic, and clinical findings are discussed.

Primary Pleomorphic Rhabdomyosarcoma of Thyroid Gland in an Adult Patient: A Case Report

Thyroid sarcoma is a very rare entity, accounting for less than 1% of all malignant thyroid tumours. Rhabdomyosarcoma (RMS) is a sarcoma subtype, which is more common in children and adolescents. In this case, a 68-year old man, presented with hoarseness and diagnosed with pleomorphic RMS, was explored. No study of primary thyroid pure RMS has been reported in the literature, with the exception of the case reports of differentiated RMS.

Adult Pleomorphic Rhabdomyosarcoma: A Multicentre Retrospective Study

BACKGROUND

Pleomorphic rhabdomyosarcoma (RMS) is a rare sub-type of RMS. Optimal treatment remains undefined.

PATIENTS AND METHODS

Between 1995 and 2014, 45 patients were diagnosed and treated in three tertiary sarcoma Centers (United Kingdom, Switzerland and Germany). Treatment characteristics and outcomes were analyzed.

RESULTS

The median age at diagnosis was 71.5 years (range=28.4-92.8 years). Median survival for those with localised (n=32, 71.1%) and metastatic disease (n=13, 28.9%) were 12.8 months (95% confidence interval=8.2-34.4) and 7.1 months (95% confidence interval=3.8-11.3) respectively. The relapse rate was 53.8% (four local and 10 distant relapses). In total, 14 (31.1%) patients received first line palliative chemotherapy including multi-agent paediatric chemotherapy schedules (n=3), ifosfamide-doxorubicin (n=4) and single-agent doxorubicin (n=7). Response to chemotherapy was poor (one partial remission with vincristine-actinomycin D-cyclophosphamide and six cases with stable disease). Median progression-free survival was 2.3 (range=1.2-7.3) months.

CONCLUSION

Pleomorphic RMS is an aggressive neoplasm mainly affecting older patients, associated with a high relapse rate, a poor and short-lived response to standard chemotherapy and an overall poor prognosis for both localised and metastatic disease.

Rhabdomyosarcoma: a rare laryngeal neoplastic entity

A case of pleomorphic rhabdomyosarcoma of the larynx is presented, which is extremely rare in a laryngeal site. The symptomatology and macroscopic aspect of the neoplasm can simulate the presence of other neoplastic variants of the larynx, and, for this reason, histological examination must be associated with immunohistochemistry for correct diagnosis and treatment.