Solitary relapse of desmoplastic small round cell tumor detected by positron emission tomography/computed tomography

Metastatic Pulmonary Desmoplastic Small Round Cell Tumor on FDG PET/CT

ABSTRACT

A 33-year-old woman presents with cough and hemoptysis for 1 month. Chest CT showed a soft tissue mass in the left upper lobe of the lung. FDG PET/CT showed multiple foci of intense activity not only in the lung but also in the lymph nodes and the bones, which was diagnosed as lung malignancy with metastases. Histopathology revealed desmoplastic small round cell tumor. Our case indicated that, although the incidence is low, desmoplastic small round cell tumor should be considered among differential diagnoses of lung malignancies.

Desmoplastic small round cell tumor 20 years after its discovery

Desmoplastic small round cell tumor (DSRCT) was proposed as a distinct disease entity by William L Gerald and Juan Rosai in 1991. Over 850 patients have been reported in the medical literature. A specific translocation, t(11;22)(p13;q12), is seen in almost all cases, juxtaposing the EWS gene to the WT1 tumor suppressor gene. DSRCT is composed of nests of small round cells with polyphenotypic differentiation, typically a mixture of epithelial, mesenchymal and neural features, surrounded by a prominent desmoplastic stroma. DSRCT has a predilection for adolescent and young adult males, and primarily involves the abdominal cavity and pelvis. Survival is low despite their initial response to multimodal treatment. Most patients relapse with disseminated disease that is unresponsive to further therapy.

FDG PET/CT imaging of desmoplastic small round cell tumor: findings at staging, during treatment and at follow-up

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a very uncommon soft-tissue tumor of children and young adults. It has an aggressive course with generally poor survival. In general the assessment of tumor burden and response has relied upon CT or MRI. However these tumors are often metabolically active and can be evaluated using FDG PET/CT imaging.

OBJECTIVE

The purpose of this study was to determine the metabolic activity of desmoplastic small round cell tumors using FDG PET/CT imaging and the potential utility of FDG PET/CT in this disease.

MATERIALS AND METHODS

Eight patients (seven male, one female; ages 2-20 years, median 11 years) with confirmed DSRCT underwent 82 positron emission tomography/computed tomography (PET/CT) scans. PET/CT was used for initial staging (seven patients, eight scans), monitoring response to therapy (eight patients, 37 scans) and for surveillance of DSRCT recurrence (six patients, 37 scans).

RESULTS

Each scan performed at diagnosis showed abnormally elevated uptake in the primary tumor. Five patients had abdominal pelvic involvement, and two of those also had thoracic disease. Six patients whose scans showed no abnormal sites of uptake at the end of therapy have had progression-free survivals of 2-10 years. One patient whose scan continued to show uptake during treatment died of disease 1.3 years from diagnosis. Another patient with persistent uptake remained in treatment 3 years after initial diagnosis. One surveillance scan identified recurrent disease.

CONCLUSION

FDG PET/CT identified elevated metabolic activity in each patient studied. Despite our small sample size, FDG PET/CT scans appear useful for the management of patients with DSCRT. Patients whose studies become negative during or following treatment may have a prolonged remission.

Desmoplastic small round cell tumor: a rare cause of a progressive brachial plexopathy

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is an uncommon, embryonic-type neoplasm, typically presenting as an abdominal mass in young men. A single case of DSRCT arising in the peripheral nervous system has been reported previously.

METHODS

The clinical course, imaging, electrophysiological, intraoperative, histopathological, molecular findings, and postoperative follow-up are reported.

RESULTS

A 43-year-old man presented with slowly progressive right brachial plexopathy. Magnetic resonance imaging revealed an enlarged medial cord with heterogeneous contrast enhancement. Histology showed a "small round cell" neoplasm with a polyphenotypic immunoprofile, including epithelial and mesenchymal markers. A pathognomonic fusion of Ewing sarcoma breakpoint region 1 and Wilms tumor 1 genes (EWSR1/WT1) was present. Treatment involved gross total excision and local radiotherapy.

CONCLUSIONS

Our findings confirm the occurrence of DSRCT as a primary peripheral nerve tumor. Despite its usually very aggressive clinical course, prolonged recurrence-free survival may be reached. Histomorphology and immunoprofile of DSRCT may lead to misdiagnosis as small cell carcinoma.

Autologous hematopoietic stem cell transplantation following high dose chemotherapy for non-rhabdomyosarcoma soft tissue sarcomas

BACKGROUND

Soft tissue sarcomas (STS) are a highly heterogeneous group of rare malignant solid tumors. Non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) comprise all STS except rhabdomyosarcoma. In patients with advanced local or metastatic disease, autologous hematopoietic stem cell transplantation (HSCT) applied after high-dose chemotherapy (HDCT) is a planned rescue therapy for HDCT-related severe hematologic toxicity. The rationale for this update is to determine whether any randomized controlled trials (RCTs) have been conducted and to clarify whether HDCT followed by autologous HSCT has a survival advantage.

OBJECTIVES

To assess the effectiveness and safety of HDCT followed by autologous HSCT for all stages of non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) in children and adults.

SEARCH METHODS

For this update we modified the search strategy to improve the precision and reduce the number of irrelevant hits. All studies included in the original review were considered for re-evaluation in the update. We searched the electronic databases CENTRAL (2012, Issue 11) in The Cochrane Library , MEDLINE and EMBASE (05 December 2012) from their inception using the newly developed search strategy. Online trials registers and reference lists of systematic reviews were searched.

SELECTION CRITERIA

Terms representing STS and autologous HSCT were required in the title or abstract. In studies with aggregated data, participants with NRSTS and autologous HSCT had to constitute at least 80% of the data. Single-arm studies were included in addition to studies with a control arm because the number of comparative studies was expected to be very low.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted study data. Some studies identified in the original review were re-examined and found not to meet the inclusion criteria and were excluded in this update. For studies with no comparator group, we synthesized the results for studies reporting aggregate data and conducted a pooled analysis of individual participant data using the Kaplan-Meyer method. The primary outcomes were overall survival (OS) and treatment-related mortality (TRM).

MAIN RESULTS

The selection process was carried out from the start of the search dates for the update. We included 57 studies, from 260 full text articles screened, reporting on 275 participants that were allocated to HDCT followed by autologous HSCT. All studies were not comparable due to various subtypes. We identified a single comparative study, an RCT comparing HDCT followed by autologous HSCT versus standard chemotherapy (SDCT). The overall survival (OS) at three years was 32.7% versus 49.4% with a hazard ratio (HR) of 1.26 (95% confidence interval (CI) 0.70 to 2.29, P value 0.44) and thus not significantly different between the treatment groups. In a subgroup of patients that had a complete response before treatment, OS was higher in both treatment groups and OS at three years was 42.8% versus 83.9% with a HR of 2.92 (95% CI 1.1 to 7.6, P value 0.028) and thus was statistically significantly better in the SDCT group. We did not identify any other comparative studies. We included six single-arm studies reporting aggregate data of cases; three reported the OS at two years as 20%, 48%, and 51.4%. One other study reported the OS at three years as 40% and one further study reported a median OS of 13 months (range 3 to 19 months). In two of the single-arm studies with aggregate data, subgroup analysis showed a better OS in patients with versus without a complete response before treatment. In a survival analysis of pooled individual data of 80 participants, OS at two years was estimated as 50.6% (95% CI 38.7 to 62.5) and at three years as 36.7% (95% CI 24.4 to 49.0). Data on TRM, secondary neoplasia and severe toxicity grade 3 to 4 after transplantation were sparse. The one included RCT had a low risk of bias and the remaining 56 studies had a high risk of bias.

AUTHORS' CONCLUSIONS

A single RCT with a low risk of bias shows that OS after HDCT followed by autologous HSCT is not statistically significantly different from standard-dose chemotherapy. Therefore, HDCT followed by autologous HSCT for patients with NRSTS may not improve the survival of patients and should only be used within controlled trials if ever considered.

Positron emission tomography for response assessment in desmoplastic small round cell tumor

BACKGROUND

Desmoplastic small round cell tumors (DSRCT) typically have a large stromal component and often are extensively disseminated in the peritoneal cavity at diagnosis. These factors contribute to difficulty in quantifying response to chemotherapy using RECIST or WHO criteria. This study compares the overall disease response to chemotherapy by fluorodeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) in patients with DSRCT.

METHODS

We conducted a retrospective chart review of 7 patients with DSRCT who were imaged by FDG-PET and CT at diagnosis and after 3 cycles of chemotherapy. Response to chemotherapy was graded according to EORTC metabolic response guidelines and RECIST.

RESULTS

All tumors demonstrated some decrease in SUVmax (51%±21%) and longest diameter (23%±8%) with chemotherapy. The best response achieved by FDG-PET was a partial response in 6 patients and by CT was a partial response in 1 patient. Measured response was concordant between the 2 modalities in 2 patients.

CONCLUSIONS

In this small series response measurement by FDG-PET did not always correlate with response measurement by CT. A greater decrease in metabolic activity as compared with size was seen in all patients. Further studies are needed to define the role of FDG-PET in assessing early response of DSRCT to chemotherapy.

Imaging of pediatric desmoplastic small-round-cell tumor with pathologic correlation

Desmoplastic small-round-cell tumors are rare aggressive malignancies that belong to the "small round blue cell" tumor family. They predominantly affect the abdomen in adolescent and young adult males. Computed tomography is currently the modality of choice both for diagnosis and follow-up assessment. In this review, the authors provide a concise yet comprehensive discussion of this condition with emphasis on the imaging findings. Pathologic correlation, differential diagnostic considerations, and treatment will also be presented.

Characteristic imaging features of desmoplastic small round cell tumour

BACKGROUND

Desmoplastic small round cell tumour (DSRCT) is a rare malignant neoplasm. Its radiological features have rarely been described.

OBJECTIVE

To assess the CT parameters characteristic of DSRCT. We also report our experience with combined FDG PET/CT in staging and follow-up for DSRCT.

MATERIALS AND METHODS

The pretreatment diagnostic CT's of 65 patients with DSRCT were evaluated. Pertinent imaging findings were catalogued, with histopathology or serial follow-up studies as reference standard. Combined FDG PET/CT examinations of 11 of these patients who underwent pretreatment imaging were also reviewed.

RESULTS

Sixty-two patients presented with primary intra-abdominal disease; three had primary extra-abdominal tumours at presentation. The most common imaging finding of patients with intra-abdominal DSRCT was multiple peritoneal soft tissue masses, with a dominant mass in the retrovesical or rectouterine location in more than half of the cases. Forty percent had metastatic disease to the liver, lungs, spleen or bones at diagnosis. FDG PET/CT accurately detected 97.4% of all DSRCT lesions.

CONCLUSION

DSRCT typically presents as a large abdominopelvic mass with widespread peritoneal involvement predominantly in young males. Familiarity with its radiological features can help guide diagnosis and treatment. Functional imaging with PET/CT offers advantage over anatomical imaging for accurate disease staging.

Imaging of desmoplastic small round cell tumour in adults

Desmoplastic small round cell tumour (DSRCT) belongs to the histological descriptive category of small round blue cell tumours. DSRCT primarily occurs in adolescents and young adults between the ages of 15 and 25 years and has a male predominance. DSRCT is an aggressive disease with a poor prognosis; timely diagnosis is therefore critical to the management of these patients. Although their radiographic appearances overlap with other aggressive malignancies, there are certain imaging features that can suggest the diagnosis and expedite the initiation of appropriate therapy. The aim of our pictorial review is to describe the imaging findings of primary and metastatic DSRCT in adults.

Autologous hematopoietic stem cell transplantation following high-dose chemotherapy for non-rhabdomyosarcoma soft tissue sarcomas

BACKGROUND

Soft tissue sarcomas (STS) are a highly heterogeneous group of rare malignant solid tumors. Non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) comprise all STS except rhabdomyosarcoma. In patients with advanced local or metastatic disease, autologous hematopoietic stem cell transplantation (HSCT) applied after high-dose chemotherapy (HDCT) is a planned rescue therapy for HDCT-related severe hematologic toxicity.

OBJECTIVES

To assess the effectiveness and safety of HDCT followed by autologous HSCT for all stages of soft tissue sarcomas in children and adults.

SEARCH STRATEGY

We searched the electronic databases CENTRAL (The Cochrane Library 2010, Issue 2), MEDLINE and EMBASE (February 2010). Online trial registers, congress abstracts and reference lists of reviews were searched and expert panels and authors were contacted.

SELECTION CRITERIA

Terms representing STS and autologous HSCT were required in the title, abstract or keywords. In studies with aggregated data, participants with NRSTS and autologous HSCT had to constitute at least 80% of the data. Comparative non-randomized studies were included because randomized controlled trials (RCTs) were not expected. Case series and case reports were considered for an additional descriptive analysis.

DATA COLLECTION AND ANALYSIS

Study data were recorded by two review authors independently. For studies with no comparator group, we synthesised results for studies reporting aggregate data and conducted a pooled analysis of individual participant data using the Kaplan-Meyer method. The primary outcomes were overall survival (OS) and treatment-related mortality (TRM).

MAIN RESULTS

We included 54 studies, from 467 full texts articles screened (11.5%), reporting on 177 participants that received HSCT and 69 participants that received standard care. Only one study reported comparative data. In the one comparative study, OS at two years after HSCT was estimated as statistically significantly higher (62.3%) compared with participants that received standard care (23.2%). In a single-arm study, the OS two years after HSCT was reported as 20%. In a pooled analysis of the individual data of 54 participants, OS at two years was estimated as 49% (95% CI 34% to 64%). Data on TRM, secondary neoplasia and severe toxicity grade 3 to 4 after transplantation were sparse. All 54 studies had a high risk of bias.

AUTHORS' CONCLUSIONS

Due to a lack of comparative studies, it is unclear whether participants with NRSTS have improved survival from autologous HSCT following HDCT. Owing to this current gap in knowledge, at present HDCT and autologous HSCT for NRSTS should only be used within controlled trials.