Desmoplastic small cell tumor: a report of three cases and a review of the literature

CXCR4-Directed Imaging and Endoradiotherapy in Desmoplastic Small Round Cell Tumors

Desmoplastic small round cell tumor (DSRCT) is a rare, radiosensitive, yet difficult-to-treat sarcoma subtype affecting predominantly male adolescents. Extensive intraperitoneal seeding is common and requires multimodal management. With no standard therapy established, the prognosis remains poor, and new treatment options are needed. We demonstrate the clinical potential of C-X-C motif chemokine receptor 4 (CXCR4)-directed imaging and endoradiotherapy in DSRCT. Methods: Eight male patients underwent dual-tracer imaging with [18F]FDG and CXCR4-directed [68Ga]pentixafor PET/CT. A visual comparison of both tracers, along with uptake quantification in active DSRCT lesions, was performed. [68Ga]pentixafor uptake was correlated with immunohistochemical CXCR4 expression on tumor cells. Four patients with end-stage progressive disease underwent CXCR4-based endoradiotherapy. We report the safety, response by RECIST 1.1, and survival after endoradiotherapy. Results: Uptake of [68Ga]pentixafor in tumor lesions was demonstrated in all patients with DSRCT, providing diagnostic power comparable to [18F]FDG PET. Corresponding CXCR4 expression was confirmed by immunohistochemistry in all DSRCT biopsies. Finally, 4 patients were treated with CXCR4-directed [90Y]endoradiotherapy, 3 in a myeloablative dose range with subsequent autologous stem cell transplantation. All 3 required transfusions, and febrile neutropenia occurred in 2 patients (resulting in 1 death). Notably, severe nonhematologic adverse events were absent. We observed signs of response in all 3 patients, translating into disease stabilization in 2 patients for 143 and 176 d, respectively. In the third patient, postmortem autopsy confirmed a partial pathologic response. Conclusion: We validated CXCR4 as a diagnostic biomarker and a promising target for endoradiotherapy in DSRCT, demonstrated its feasibility, and provided the first evidence of its clinical efficacy.

Advances in the treatment of pediatric solid tumors: A 50-year perspective

In the United States, more than 10 000 cancers occur annually in children aged 0-14 years, and more than 5000 in adolescents aged 15-19. In the last 50 years, significant advances have been made in imaging, molecular pathology, stage and risk assessment, surgical approach, multidisciplinary treatment, and survival for pediatric solid tumors (particularly neuroblastoma, Wilms tumor, rhabdomyosarcoma, and hepatoblastoma). Moreover, the molecular driver for fibrolamellar hepatocellular carcinoma, which occurs in adolescence and young adulthood, has been identified.

Desmoplastic Small Round Cell Tumor of Pancreatic Origin in a Young Child: A Case Report and Review of Literature

BACKGROUND Desmoplastic small round cell tumor (DSRCT) is a rare lethal malignant tumor with young male predominance. The majority of cases arise in the abdominopelvic region and are hypothesized to have a mesothelial origin. However, extra-abdominal and extraperitoneal DSRCT have been reported. It is extremely uncommon for the pancreas to be a primary site for DSRCT, and only 5 cases have previously been reported in the English literature. Clinically, DSRCT has a wide range of presentations from asymptomatic to life-threatening comorbidity, and it responds poorly to treatment despite aggressive therapy. CASE REPORT We report a previously healthy 9-year-old boy with an incidentally discovered abdominal mass of pancreatic origin. All necessary laboratory investigations were within normal limits. Computed tomographic imaging showed a huge left-side retroperitoneal mass measuring 15 cm in the greatest dimension that was accompanied by vascular encasement. The mass was resected successfully. Histopathological examination along with ancillary tests favored a diagnosis of DSRCT over other small round blue cell tumors. Detection of translocation t(11;22)(p13;q12) with EWSR1-WT1 gene fusion, based on reverse transcription-polymerase chain reaction analysis, confirmed the diagnosis. Approximately 7 months later, the tumor recurred with mesenteric lymph nodes metastasis and the child was placed on palliative therapy. CONCLUSIONS It is worthwhile to consider DSRCT in the differential diagnosis of small round blue cell tumors, even in unusual sites, in a pediatric age group. Due to the poor prognosis, owing to chemotherapy resistance and a high rate of recurrence with significant tumor burden, reaching a precise diagnosis of DSRCT is essential. Almost all cases harbor the hallmark molecular alteration of t(11;22)(p13;q12) with EWSR1-WT1 gene fusion. Debulking surgery paired with a chemotherapy regimen comprising vincristine, doxorubicin, and cyclophosphamide and ifosfamide + etoposide has been shown to improve overall survival rate compared with other chemotherapeutic agents. However, no targeted therapeutic modality has been developed.

High-Dose Chemotherapy with Stem Cell Rescue in Desmoplastic Small Round Cell Tumor: A Single-Institution Experience and Review of the Literature

Purpose

Desmoplastic small round cell tumor (DSRCT) is a rare cancer that predominantly affects males averaging 21 years of age at the time of diagnosis. We describe four cases from our institution and place them within the context of a comprehensive review of the literature.

Patients and Methods

Study population included any patient who received treatment at Children's Hospital at Montefiore (CHAM) with histologic diagnosis of DSRCT. A search of the electronic databases PubMed, Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE for the terms “desmoplastic” AND “small” AND “round” AND “cell” AND “tumor” was performed.

Results

One CHAM patient died of disease at 39 months, one patient has relapsed disease at 40 months, and two patients have no evidence of disease at 60 and 91 months. In the literature review, the 3-year OS was 36% and 5-year OS was 13%. There was a statistically significant difference in OS between no transplant and SCT in remission (p=0.004); however, there was no difference between no transplant and SCT not in remission (p=0.23).

Conclusion

Given the poor prognosis in DSRCT, this study supports further prospective research into the possible benefit of consolidation of autologous SCT in patients with DSRCT who are in remission, with the alternative inference that these patients in remission may fare well without SCT. Our retrospective review of the literature does not support SCT for patients who are not in remission.

Complete Response to Chemotherapy in Intra-Abdominal Desmoplastic Small round Cell Carcinoma. A Case Report

Aims and background

The authors report the case of a 23-year-old woman affected by intra-abdominal desmoplastic small round cell tumor (DSRCT) who obtained a complete response to multiagent chemotherapy. DSRCT is a rare, highly aggressive neoplasm generally arising in young people and seldom in females (about 20 cases described in the literature).

Methods

The patient underwent surgical resection of a large 15 × 15 cm mass located in the right lower abdominal quadrant, but after only 2 months later, two liver metastasis were noted. Thus, she was subjected to an aggressive antineoplastic treatment consisting of three groups of alternating non-cross resistant multiagent regimens administered every 21 days (cis-platin-etoposide-adriamycin-bleomicin; gemcitabine-ifosfamide-dacarbazine; methotrexate-5-fluorouracilfolinic acid) for a total of 9 administrations.

Results

After one cycle of treatment including the administration of all the three alternated schemes of chemotherapy, a complete disappearance of liver disease was noted. The treatment was relatively well-tolerated and the toxicity was acceptable. At present, after 15 months from diagnosis and 12 months after starting chemotherapy, the patient is disease-free and in good health.

Conclusions

Even though this study regards only a single patient, it is noteworthy because of the rarity of this neoplasm and because of the infrequent complete responses reported in the literature. The efficacy and manageability of the treatment, suggests that both the timing and schedule used could constitute an important therapeutical option for this aggressive and poorly chemo-responsive tumor.

Abdominal desmoplastic small round cell tumor without extraperitoneal metastases: Is there a benefit for HIPEC after macroscopically complete cytoreductive surgery?

Background

Desmoplastic Small Round Cell Tumor (DSRCT) is a rare disease affecting predominantly children and young adults and for which the benefit of hyperthermic intraperitoneal chemotherapy (HIPEC) after complete cytoreductive surgery (CCRS) remains unknown.

Methods

To identify patients with DSRCT without extraperitoneal metastases (EPM) who underwent CCRS between 1991 and 2015, a retrospective nation-wide survey was conducted by crossing the prospective and retrospective databases of the French Network for Rare Peritoneal Malignancies, French Reference Network in Sarcoma Pathology, French Sarcoma Clinical Network and French Pediatric Cancer Society.

Results

Among the 107 patients with DSRCT, 48 had no EPM and underwent CCRS. The median peritoneal cancer index (PCI) was 9 (range: 2–27). Among these 48 patients, 38 (79%) had pre- and/or postoperative chemotherapy and 23 (48%) postoperative whole abdominopelvic radiotherapy (WAP-RT). Intraperitoneal chemotherapy was administered to 11 patients (23%): two received early postoperative intraperitoneal chemotherapy (EPIC) and nine HIPEC. After a median follow-up of 30 months, the median overall survival (OS) of the entire cohort was 42 months. The 2-y and 5-y OS were 72% and 19%. The 2-y and 5-y disease-free survival (DFS) were 30% and 12%. WAP-RT was the only variable associated with longer peritoneal recurrence-free survival and DFS after CCRS. The influence of HIPEC/EPIC on OS and DFS was not statistically conclusive.

Conclusion

The benefit of HIPEC is still unknown and should be evaluated in a prospective trial. The value of postoperative WAP-RT seems to be confirmed.

Clinical features and outcomes of 20 patients with abdominopelvic desmoplastic small round cell tumor

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is a rare mesenchymal malignancy. We describe our experience with treating DSRCT at a large sarcoma referral center.

METHODS

A retrospective chart review was performed on DSRCT patients referred to our institution (1998-2014). Pathology specimens were reviewed to confirm the diagnosis. Clinical and imaging were extracted and summarized with descriptive statistics. Univariate analysis was performed to evaluate the association between patient, tumor, and treatment variables and overall survival (OS).

RESULTS

In this study cohort of 20 patients, median age at presentation was 29 y (range 18-43) and 90% were male. Fifty-five percent presented with metastasis. Patients underwent chemotherapy (n = 20), radiation therapy (n = 3), and cytoreductive surgery (CRS) (n = 5). Median OS was 22 m (interquartile range: 12-28 m). Five-year OS rate was 20%. Extra-abdominal metastasis was associated with a higher hazard ratio (HR) of mortality (HR: 3.1, 95% C.I. 1.0-9.4, p = 0.04), while CRS improved OS (HR: 0.1, 95% C.I. 0.03-0.7, p = 0.02).

CONCLUSIONS

Despite aggressive treatment, less than half of the patients were dead of DSRCT within 2 years of presentation. Although a select group of patients who underwent CRS had improved OS, novel treatments are urgently needed.

Scrotal wall metastasis from a primary lung adenocarcinoma

This a case of a 77 years old male heavy smoker, known to have Combined Pulmonary Fibrosis and Emphysema complicated by a primary invasive adenocarcinoma of the lung with bone metastasis, who presented with a two weeks history of right inguino-scrotal pain and swelling.

Imaging studies revealed a right paratesticular formation that appeared to involve the epididymis and the scrotal wall.

A biopsy of the mass showed morphological and Immunophenotypic features in favor of metastasis of an adenocarcinoma of the lung.

Based on our literature review, there are only few published cases about scrotal wall metastasis of a lung primary.

Desmoplastic small round cell tumor: report of 2 cases treated with chemotherapy alone or in combination with bevacizumab

Here, we present 2 case reports of patients with desmoplastic small round cell tumor (DSRCT), a very rare and aggressive mesenchymal cancer, and we discuss 2therapeutic options for this sarcoma. This report focuses on men aged 22 and 37 years, respectively. The first patient presented with an abdominopelvic mass which was not suitable for surgery. He underwent chemotherapy (adriblastina and cisplatin) with a brief partial remission and survival time of 13 months. The second patient presented with an abdominal mass and underwent partial resection. He received chemotherapy and bevacizumab, resulting in a partial remission and a survival time of 34 months. The extent of surgery and monoclonal antibody use probably had a positive impact on survival. It is necessary to include specific targeted therapies in an attempt to improve survival. Surprisingly, positron emission tomography was not effective in restaging of the second patient, emphasizing the importance of computed tomography or magnetic resonance in DSRCT.

Desmoplastic small round cell tumour: characteristics and prognostic factors of 41 patients and review of the literature

Background

Desmoplastic small round cell tumour (DSRCT) is a rare but frequently fatal sarcoma, and many of its characteristics still require further clarification.

Methods

We retrospectively analysed 41 patients treated at or referred to two regional referral centres in the UK between 1991 and 2012. A review of the current literature was also performed.

Results

The median age of presentation was 27 years (range 16 to 45 years), with a male-to-female ratio of 3:1. Ninety percent of patients had disease in the abdomen. The median size of the presenting tumour was 13 cm (range 3.5 to 23 cm), and 80% had metastatic disease at diagnosis, mainly in the liver (33%) and lungs (21%). Time-to-progression (TTP) was 3.9, 2.3 and 1.1 months after first-, second- and third-line chemotherapy, respectively. First-line treatment with VIDE chemotherapy appeared to confer the longest TTP (median 14.6 months). Ifosfamide and doxorubicin resulted in TTP of >3.8 months when used in any-line setting. Eleven patients received targeted agents as part of a clinical trial. After a median follow-up of 14 months, the overall median survival (MS) was 16 months. There was no difference in MS with regards to age, gender, or size of the presenting tumour. Patients with extra-abdominal disease survived longer compared to those with tumours in the abdomen (all still alive vs MS of 15 months; P = 0.0246). Patients with non-metastatic intra-abdominal disease who underwent surgery had an MS of 47 months (16 months for those who did not have surgery; P = 0.0235). Radiotherapy for locoregional control in patients with metastatic intra-abdominal DSRCT was associated with longer survival (MS of 47 vs 14 months; P = 0.0147).

Conclusions

DSRCT is a rare but often fatal disease that mainly affects younger male patients. Those with intra-abdominal DSRCT have a poorer prognosis, although surgical resection for localised disease and radiotherapy in the metastatic setting are associated with improved survival. A patient’s age, gender and size of presenting tumour do not have prognostic significance.

Primary desmoplastic small round cell tumor of the testis: A case report and review of the literature

Desmoplastic small round cell tumors (DSRCTs) are extremely rare and mainly affect adolescents and young adults. The tumors are usually involved with the abdominal area and/or the pelvic peritoneum. Only a small number of cases have been reported concerning DSRCTs of the testicular region. The present study reports a case of DSRCT of the testis with radical orchectomy and systemic chemotherapy, leaving the patient disease-free for 14 months. However, the patient died of multiple metastasis 12 months later. Furthermore there is a review of the English literature to analyze the incidence, site of origin, imaging and pathological characteristics of DSRCT.

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.

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.

Clinical outcomes of patients with desmoplastic small round cell tumor of the peritoneum undergoing autologous HCT: a CIBMTR retrospective analysis

Desmoplastic small round cell tumor of the peritoneum (DSRCTP) is a rare, frequently fatal tumor. This retrospective study, based on CIBMTR registry data, describes the largest reported cohort of DSRCTP patients who have undergone Auto-SCT. The probabilities of disease-free survival (DFS) at 1 year for patients in CR and not in CR were 75% (95% confidence interval: 48-94%) and 35% (15-59%), respectively. The probability of OS at 3 years was 57% (29-83%) and 28% (9-51%) for patients in CR and not in CR, respectively. Median survival for the entire cohort was 31 months (36 months and 21 months for those in CR and not in CR, respectively). Engraftment at 42 days was 97% (88-100%). Treatment-related mortality was low, with only one death in the first 100 days. Auto-SCT is a tolerable approach in patients with DSRCTP, with the greatest benefit seen in those patients who obtain CR. For those not in CR, the median OS in this series is greater than previously reported (21 months vs 17 months), suggesting Auto-SCT is useful in prolonging DFS and OS, even in patients with residual or persistent disease pre-transplant.

Desmoplastic small round cell tumors with EWS-WT1 fusion transcript in children and young adults

BACKGROUND

The presence of the EWS-WT1 gene fusion transcript (GFT) is characteristic of desmoplastic small round cell tumor (DSRCT), a rare and very aggressive disease for which the treatment has not yet been clearly standardized.

METHODS

This was a retrospective national multicenter analysis of young patients <30 years with tumors expressing the EWS-WT1-GFT, designed to determine whether extensive surgery had an impact on survival.

RESULTS

Between 1995 and 2006, a EWS-WT1-GFT was detected in the tumors of 38 patients, 17 (44.7%) of whom had had a different initial pathologic diagnosis prior to molecular testing. Mean age was 13.2 years (range: 4-29.7 years). Only 9 patients (24%) had localized disease. Treatment was heterogeneous. Nine patients had "limited" surgical resections and 22 underwent "extensive" surgery. Two-year event-free survival and overall survival were 14.4% and 50%, respectively. Among the five patients who were alive in complete remission, four had undergone extensive and complete surgery.

CONCLUSIONS

Detection of the EWS-WT1-GFT plays a major role in the diagnosis of DSRCT. No survival difference was observed according to extent of surgery, but complete surgery seemed to offer the best chance of long-term survival. High-dose chemotherapy or local radiotherapy did not appear to improve survival in this retrospective analysis, but larger prospective studies are needed to provide definitive conclusions on the role of these treatments.

Desmoplastic small round cell tumor: current management and recent findings

Desmoplastic small round cell tumor (DSRCT) is a rare and highly aggressive mesenchymal tumor that develops in the abdominal cavity of young men adults. Patients typically present with symptoms of abdominal sarcomatosis. Diagnosis is based on histological analysis of biopsies which typically show small round blue cells in nests separated by an abundant desmoplastic stroma. DSRCT is associated with a unique chromosomal translocation t(11:22) (p 13; q 12) that involves the EWSR1 and WT1 genes. The prognosis is particularly poor; median survival ranges from 17 to 25 months, largely due to the presentation of the majority of patients with metastatic disease. Management of DSRCT remains challenging and current schemes lack a significant cure rate despite the use of aggressive treatments such as polychemotherapy, debulking surgery and whole abdominal radiation. Several methods are being evaluated to improve survival: addition of chemotherapy and targeted therapies to standard neoadjuvant protocol, completion of surgical resection with HIPEC, postoperative IMRT, treatment of hepatic metastases with [(90)Y]Yttrium microsphere liver embolization.

Ewing sarcoma/peripheral primitive neuroectodermal tumor and related tumors

Ewing sarcoma/peripheral primitive neuroectodermal tumor (EWS/pPNET) and other tumors with EWS gene rearrangements encompass a malignant and intermediate neoplasm with a broad anatomic distribution and a wide age range but a predilection for soft tissue in children, adolescents, and young adults. The overlapping histologic, immunohistochemical and cytogenetic and molecular genetic features create diagnostic challenges despite significant clinical and prognostic differences. Ewing sarcoma is the 3rd most common sarcoma in children and adolescents, and desmoplastic small round cell tumor is a rare neoplasm that occurs more often in older children, adolescents, and young adults. Pathologic examination is complemented by immunohistochemistry, cytogenetics, and molecular genetics. This article reviews the clinicopathologic features of EWS/pPNET and desmoplastic small round cell tumor in the spectrum of tumors with EWS gene rearrangements. Other tumors with different histopathologic features and an EWS gene rearrangement are discussed elsewhere in this volume.

Malignant small round cell tumors

Malignant small round cell tumors are characterised by small, round, relatively undifferentiated cells. They generally include Ewing's sarcoma, peripheral neuroectodermal tumor, rhabdomyosarcoma, synovial sarcoma, non-Hodgkin's lymphoma, retinoblastoma, neuroblastoma, hepatoblastoma, and nephroblastoma or Wilms’ tumor. Other differential diagnoses of small round cell tumors include small cell osteogenic sarcoma, undifferentiated hepatoblastoma, granulocytic sarcoma, and intraabdominal desmoplastic small round cell tumor. Differential diagnosis of small round cell tumors is particularly difficult due to their undifferentiated or primitive character. Tumors that show good differentiation are generally easy to diagnose, but when a tumor is poorly differentiated, identification of the diagnostic, morphological features is difficult and therefore, no definitive diagnosis may be possible. As seen in several study reports, fine needle aspiration cytology (FNAC) has become an important modality of diagnosis for these tumors. The technique yields adequate numbers of dissociated, viable cells, making it ideally suitable for ancillary techniques. Typically, a multimodal approach is employed and the principal ancillary techniques that have been found to be useful in classification are immunohistochemistry and immunophenotyping by flow cytometry, reverse transcriptase polymerase chain reaction (RT-PCR), fluorescence in situ hybridization (FISH), and electron microscopy. However, the recent characterization of chromosomal breakpoints and the corresponding genes involved in malignant small round cell tumors means that it is possible to use molecular genetic approaches for detection.

Oxaliplatin, irinotecan, and gemcitabine: a novel combination in the therapy of progressed, relapsed, or refractory tumors in children

Therapeutic options for unresectable neuroendocrine carcinomas and relapsed or refractory solid tumors are still limited in pediatric patients. We present a retrospective review of 12 children (3 to 16 y) in a case series treated with a novel combination of oxaliplatin, irinotecan, and gemcitabine (triple therapy). We defined its feasibility in a mainly outpatient setting and assessed its toxicity and effectiveness. Three patients with unresectable neuroendocrine carcinomas received triple therapy as first-line treatment; 9 children with relapsed or refractory solid tumors of different entities were assigned after failure of standard treatment protocols. The treatment schedule comprised oxaliplatin (85 mg/m²), irinotecan (175 mg/m²), and gemcitabine (1,000 mg/m²), the latter to be repeated on day 8. A median of 7 cycles was applied. Nine of 12 patients showed hematotoxicity 0-III degrees. Gastrointestinal toxicity I-II degrees were handled satisfactorily by supportive drugs. Tumor response was defined as partial response in 1 of 12 children, stable disease in 8 of 12 children, and progressive disease in 3 of 12 children with a median time of disease control of 7 months. We regard triple therapy as a well-tolerated outpatient treatment option offering children a high quality of life and showing considerable effectiveness in delaying tumor progress.

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.

A pictorial review of imaging of abdominal tumours in adolescence

Neoplastic abdominal tumours, particularly those originating from embryonal tissue (such as hepatoblastoma and nephroblastoma) and neural crest cells (such as neuroblastoma), are well-documented in young children. Neoplasms of adulthood, most commonly carcinoma of different visceral organs, are also well-documented. Abdominal tumours in adolescence constitute a distinct pathological group. The radiological features of some of these tumours have been described only in isolated reports. The purpose of this pictorial essay was to review the imaging findings of various kinds of abdominal tumours in adolescent patients (with an age range of 10-16 years) who presented to the Children Cancer Center of our institution in the past 15 years. Some tumours, though rare, have characteristic imaging appearances (especially in CT) that enable an accurate diagnosis before definite histological confirmation.

Cytoreductive surgery associated to hyperthermic intraperitoneal chemoperfusion for desmoplastic round small cell tumor with peritoneal carcinomatosis in young patients

PURPOSE

Desmoplastic round small cell tumor (DRSCT) is a rare intraabdominal mesenchymal tissue neoplasm in young patients and spreads through the abdominal cavity. Its prognosis is poor despite a multimodal therapy including chemotherapy, radiotherapy, and surgical cytoreduction (CS). hyperthermic intraperitoneal chemotherapy (HIPEC) is considered as an additional strategy in the treatment of peritoneal carcinomatosis; for this reason, we planned to treat selected cases of children with DRSCT using CS and HIPEC.

METHODS

Peritoneal disease extension was evaluated according to Gilly classification. Surgical cytoreduction was considered as completeness of cytoreduction-0 when no macroscopic nodule was residual; HIPEC was performed according to the open technique.

RESULTS

We described 3 cases: the 2 first cases were realized for palliative conditions and the last one was operated on with curative intent. There was no postoperative mortality. One patient was reoperated for a gallbladder perforation. There was no other complication related to HIPEC procedure.

CONCLUSIONS

Surgical cytoreduction and HIPEC provide a local alternative approach to systemic chemotherapy in the control of microscopic peritoneal disease in DRSCT, with an acceptable morbidity, and may be considered as a potential beneficial adjuvant waiting for a more specific targeted therapy against the fusion protein.

Desmoplastic small round cell tumor of the mandible in a child with unusual plantar metastasis

Desmoplastic small round-cell tumor (DSRCT) is a rare and aggressive tumor that usually affects young males. Abdominal or pelvic disease is generally present in patients with DSRCT. Despite multimodality treatment, it still remains highly aggressive and has poor prognosis. We report a 16-year-old male with DSRCT in the mandible, an unusual site of the disease, treated with chemo-radiotherapy but recurred in an unexpected site 5 months after the completion of treatment.

A case of desmoplastic small round cell tumor diagnosed in a young female patient

Desmoplastic small round cell tumor is a very rare malignancy. We report the case of a 26-year-old woman who suffered from dyspepsia and abdominal pain for 2 months. We performed an endoscopic biopsy of the duodenal mass and diagnosed her disease as desmoplastic small round cell tumor using immunohistochemical staining, fluorescence in situ hybridization, and reverse transcriptase polymerase chain reaction. Because the mass invaded the pancreas and superior mesenteric vein as well as duodenum and the disease was disseminated to liver and peritoneum, she received palliative chemotherapy using vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide. The maximal response to chemotherapy was stable disease. The patient expired 9 months after diagnosis.

[Desmoplastic small round-cell tumor: two cases of diffuse abdominopelvic infiltration]

Desmoplastic small round-cell tumors are a rare malignant tumor that affects male children and young adults. It frequently presents as a large abdominal mass with widespread peritoneal involvement at diagnosis. We report two cases of desmoplastic small round-cell tumors, with diffuse infiltration in the abdomen and pelvis in two adult caucasian males. The first case-report is a middle-aged man and the second a young adult man with early recurrence and diffuse metastatic lymph nodes. Both tumors have a distinct morphology, a polyphenotypic differentiation and a t(11;22) (p13;q12) translocation. The prognosis remains poor and leads to death in most cases, despite surgical resection, radiotherapy and high-dose chemotherapy.

Sister Mary Joseph's nodule as presenting sign of a desmoplastic small round cell tumor

Umbilical metastases, also named Sister Mary Joseph's nodules, are well documented in the adult population and most often represent an underlying intra-abdominal malignancy, usually a carcinoma of gastrointestinal or gynecologic origin. They are indicative of widespread abdominal disease and are associated with a poor prognosis. An extensive review of the literature reveals only two such presentations in the pediatric population. A 14-year-old male presented with an umbilical mass, which was found to be a metastatic lesion of a desmoplastic small round cell tumor (DSRCT) of the abdomen. The diagnosis of an intra-abdominal malignancy, most commonly a DSRCT, should be considered in the presence of an umbilical mass in a child.

Desmoplastic small round cell tumour: a review of literature and treatment options

INTRODUCTION

Desmoplastic Small Round Cell Tumour (DSRCT) is a rare but aggressive malignancy with poor outcome.

AIMS

To review the clinico-pathological features and radiological, histological and tumour markers of the disease and to evaluate the evidence for treatment options available.

METHODS

We report a clinical case from our centre and have conducted a review of the literature from Medline (Pubmed) database from 1989 to 2007.

RESULTS

DSRCT typically presents with advanced disease and is prevalent in young males. Lack of staging criteria and small numbers of patients make comparison of evidence for its treatment difficult.

CONCLUSION

Surgical excision is only recommended for non-metastatic disease with combination chemo-radiotherapy as an adjunct. These modalities used in isolation may have less impact. Furthermore, the side effect profile from radiotherapy may outweigh any survival benefit. For advanced disease, symptom control is most important as these modalities impact survival minimally and palliation of secondary symptoms is paramount. Multi-disciplinary team and specialist centre review for histology and oncology are essential in managing this disease process and will enable greater numbers of patients to be enrolled into therapeutic trials and future evolving therapies.

Desmoplastic small round cell tumor masquerading as advanced ovarian cancer

Desmoplastic small round cell tumor (DSRCT) is a rare abdominal malignancy usually diagnosed in young adult males. Most patients have widespread disease at presentation, with an organ of origin difficult to ascertain. A 33-year-old female presented to her gynecologist with complaints of suprapubic pressure, abdominal pain, and increased abdominal girth. She had a large intraabdominal tumor on ultrasound, thought to be ovarian cancer. She underwent surgical exploration, which confirmed a malignancy, but the exact etiology was uncertain. Final pathology was consistent with DSRCT. DSRCT is a rare malignancy that can mimic other more commonly seen tumors such as lymphoma and ovarian cancer. When encountering an extensive intraabdominal malignancy of uncertain etiology, DSRCT should be in the differential diagnosis.

Desmoplastic small round cell tumor of the pleura

Desmoplastic small round cell tumor (DSRCT) is a rare neoplasm with aggressive behavior. Usually it presents as a peritoneal mass, although other cases in various locations have been described. Since less than 10 cases of primary DSRCT in the pleura have been described, it is of interest to report a pediatric case arising from the pleura. The diagnosis was confirmed by molecular detection of the EWS/WT-1 fusion gene product. Multidisciplinary treatment with chemotherapy, radiotherapy, and surgical resection resulted in a progression-free survival time above the median survival, suggesting that this conventional approach could prove effective for this rare and very aggressive malignancy.

Autologous stem cell transplantation for high-risk Ewing's sarcoma and other pediatric solid tumors

The prognosis for many pediatric and young adult patients with solid tumors that have metastasized at the time of diagnosis or have relapsed after therapy remains very poor. The steep dose-response curve of many of these tumors to alkylating agents makes myeloablative chemotherapy followed by autologous stem cell transplantation (ASCT) an attractive potential therapy. The role of ASCT for these high-risk patients is yet to be conclusively determined. We have transplanted 36 patients on two consecutive protocols with a variety of histological diagnoses. Overall survival (OS) was 63% (95% CI: 47-79%) at 1 year and 33% (95% CI: 16-50%) at 3 years. Patients with a diagnosis of Ewing's sarcoma (ES) or desmoplastic small round cell tumor (DSRCT) had significantly better survival than those with other diagnoses with estimated 3-year OS of 54% (95% CI: 29-79%) for this group of patients (P = 0.03). There were two transplant-related deaths both attributable to hepatic veno-occlusive disease. Median follow-up among survivors is 3.5 years (range: 0.6-7.9 years). These data justify continued investigation of ASCT as a consolidation therapy in patients with metastatic or relapsed ES and DSRCT.

Combined resection and multi-agent adjuvant chemotherapy for desmoplastic small round cell tumor arising in the abdominal cavity: Report of a case

Desmoplastic small round cell tumor (DSRCT) is a rare, highly aggressive malignancy with distinctive histological features: a nesting pattern of cellular growth within dense desmoplastic stroma, occurring in young population with male predominance. The mean survival period is only about 1.5-2.5 years. The tumor has co-expressed epithelial, muscle, and neural markers in immunohistochemical studies. This work reports a 27-year-old man presenting with hematemesis and chronic constipation. Serial studies including endoscopy, upper gastrointestinal series, abdominal computed tomography and barium enema study showed disseminated involvement of visceral organs. The patient underwent aggressive surgery and received postoperative adjuvant chemotherapy consisting of 5-fluorouracil, cyclophosphamide, etoposide, doxorubicin, and cisplatin. He survived without any disease for 20 mo after the surgery. No standard treatment protocol has been established. Aggressive surgery combined with postoperative multi-agent adjuvant chemotherapy is justified not only to relieve symptoms but also to try to improve the outcome in this advanced DSRCT young patient.

Intraabdominal desmoplastic small round cell tumors: a diagnostic and therapeutic challenge

BACKGROUND

Intraabdominal desmoplastic small round cell tumors (IDSRCT) are uncommon but aggressive tumors that occur in young males. To the authors' knowledge, only limited data are available on the natural history and optimal treatment of this disease.

METHODS

The authors reviewed 12 patients with IDSRCT who were treated at their institution between January 1991 and December 2001.

RESULTS

All patients were males, with a median age of 26 years. All patients were symptomatic at the time of presentation, with a mean duration of symptoms of 2 months. Common presenting symptoms and signs were abdominal pain (67% of patients), palpable abdominal mass (58% of patients), abdominal distension (42% of patients), and hepatomegaly (33% of patients). Six patients (50%) had distant metastases at presentation. Five patients underwent biopsy only. Surgical resection was attempted in seven patients and included macroscopic total resection in three patients and debulking in four patients. All of those patients subsequently developed recurrent or progressive disease, which required a second operation in six patients. Overall, 6 patients (50%) developed symptomatic intestinal obstruction requiring surgical management, and 3 patients (25%) developed ureteral obstruction. All 12 patients received multiagent chemotherapy. Seven patients (55%) also received radiation therapy. The median survival of patients who underwent surgical resection was 34 months, whereas the median survival of patients who underwent biopsy alone was 14 months. One patient remained alive 72 months after he underwent complete resection of primary and recurrent tumors, and 1 patient remained alive with disease 32 months after he underwent complete resection of a primary tumor.

CONCLUSIONS

Patients with IDSRCT presented with a short duration of nonspecific symptoms, and the disease was fatal almost uniformly, regardless of the treatment modality used. Surgical resection may prolong survival in some patients.

Clinical perspective on desmoplastic small round-cell tumor

Rare diseases are often associated with uninformed medical decisions and poorly executed treatments because of inexperience of the physicians. Desmoplastic small round-cell tumor is a rare disease that is a form of peritoneal surface malignancy usually affecting young males, with a mean survival of 29 months. In order to begin to build a more knowledgeable clinical pathway all 7 patients treated at the Washington Hospital Center were studied and compared to patients described in the medical literature. Clinical and pathological data, tumor distribution, cytoreductive surgery, completeness of cytoreduction and survival were recorded and analyzed. The first most common symptoms were pain, increased abdominal girth and palpable abdominal mass in our patients and in the literature review. The overall survival did not improve with cytoreductive surgery plus intraperitoneal chemotherapy (mean survival 32 months); however, 2 long-term survivors who responded to systemic chemotherapy of 55 and 101 months were recorded. The latter may be the longest survivor reported in the literature. No consistent response to chemotherapy was observed in our patients or in any literature review. Complete surgical removal of this malignancy did not correlate with survival in our patients. The absence of improved survival of our aggressively treated patients as compared to the literature was thought to be a consequence of an advanced stage of the disease. A new comprehensive approach that uses complete clearing of cancer by surgery and perioperative systemic and perioperative intraperitoneal chemotherapy as early as is possible in the natural history of the disease emerged as goals for future management.

Desmoplastic small round cell tumour: a description of two cases and review of the literature

BACKGROUND

Desmoplastic small round cell tumour (DSRCT) is a recently described neoplasm, typically occurring in adolescent and young males. It usually shows an aggressive behaviour, presents in the abdomen, often with diffuse peritoneal implants. It has been demonstrated to be a chemosensitive tumour, generally with short-lasting response and poor survival gain from systemic chemotherapy. The authors report two additional cases of DSRCT and review the available medical literature.

PATIENTS AND METHODS

Two young males with intra-abdominal DSRCT were treated with a first-line chemotherapy including carboplatin, doxorubicin and etoposide.

RESULTS

Both of the patients obtained a partial response after first-line chemotherapy. The first patient started, subsequently, CD34+ stem cell mobilisation with high-dose cyclophosphamide (7 g/m(2)) in order to perform high-dose chemotherapy, but CD34+ cell count was insufficient to practice leukapheresis; he died 34 months after the diagnosis because of progression of the disease. The second patient underwent cytoreductive surgery, but progressed 2 months later despite second-line treatment; he died 16 months after the diagnosis.

CONCLUSION

This experience confirms that DSRCT may be considered a chemosensitive tumour, highly aggressive, with short-lasting response to chemotherapy. Anyway, the recent literature suggests that multidisciplinary treatment including chemotherapy, surgery and radiation might be the proper approach to this rare malignancy.

Peripheral blood stem cell support reduces the toxicity of intensive chemotherapy for children and adolescents with metastatic sarcomas

BACKGROUND

To increase the dose intensity (DI) of chemotherapy for pediatric patients with metastatic sarcomas, including the Ewing sarcoma family of tumors (ESFT) and rhabdomyosarcoma (RMS), the authors tested the feasibility of an intensive regimen supported by granulocyte-colony stimulating factor (G-CSF) and peripheral blood stem cells (PBSC).

METHODS

Twenty-three children and adolescents with metastatic sarcomas received vincristine, doxorubicin, cyclophosphamide, ifosfamide, sodium mercaptoethanesulfonate (mensa), and etoposide (VACIME) chemotherapy, consisting of 8 courses of vincristine 2 mg/m(2) on Day 0, doxorubicin 37.5 mg/m(2) per day on Days 0-1, cyclophosphamide 360 mg/m(2) per day on Days 0-4, ifosfamide 1800 mg/m(2) per day on Days 0-4, mesna 2400 mg/m(2) per day, and etoposide 100 mg/m(2) per day on Days 0-4. Doxorubicin was omitted in Courses 7 and 8. G-CSF was given after each course of therapy. Courses of therapy were repeated every 21 days or as soon as hematopoietic recovery permitted. PBSC were collected twice: first, after Course 2 (infused after Courses 3 and 4) and, second, after Course 4 (infused after Courses 5 and 6). Surgical resection followed Course 6, and radiotherapy followed Course 8.

RESULTS

PBSC collections were adequate in 91% of all harvests. The mean DI was 82% (standard deviation, 14%) of the intended DI, which was greater than historic data without PBSC support. Seventeen patients (74%) achieved a complete response (CR), 12 patients with chemotherapy alone and 5 more patients after undergoing surgical resection. Fifteen patients developed progressive disease, with a 2-year event free survival (EFS) rate of 39% (95% confidence interval, 19-59%). Hematopoietic toxicity was severe and cumulative, although it was less than that seen previously without PBSC support.

CONCLUSIONS

PBSC-supported multicycle chemotherapy is a feasible method to increase chemotherapy DI for pediatric patients with metastatic sarcomas. Although the CR rate compared favorably with previously reported response rates, the 2-year EFS rate was similar to that achieved with other intensive regimens.

Whole abdominopelvic radiotherapy for desmoplastic small round-cell tumor

PURPOSE

Desmoplastic small round-cell tumor (DSRCT) is a rare, recently described intraperitoneal malignancy occurring predominantly in adolescent boys. Our objective was to evaluate the feasibility and outcome of whole abdominopelvic irradiation (WAPI) as part of a combined modality protocol for patients with DSRCT.

METHODS AND MATERIALS

The records of all 21 patients treated with WAPI for DSRCT at our institution from 1992 to 2001 were retrospectively reviewed. Patients were treated on an institutional protocol with 7 cycles of an alkylator-based chemotherapy. After maximal surgical debulking, patients were treated with external beam radiotherapy to the whole abdomen and pelvis to a dose of 30 Gy.

RESULTS

All 21 patients completed the prescribed treatment. The median follow-up was 28 months. The overall survival and relapse-free survival rate at 3 years was 48% and 19%, respectively. The median survival was 32 months, and the median time to relapse was 19 months. Most relapses were intraperitoneal and/or hepatic. Acute toxicities included Radiation Therapy Oncology Group Grade 2 upper and lower gastrointestinal toxicity in 81% and 71% of patients, respectively. All patients experienced acute hematologic toxicity, with Grade 4 thrombocytopenia, leukopenia, and anemia in 76%, 29%, and 33%, respectively. The major long-term toxicity was small bowel obstruction, which occurred in 7 patients (33%) after surgery and WAPI.

CONCLUSION

DSRCT is a rare and highly lethal disease, requiring aggressive multimodality therapy. WAPI is feasible in conjunction with intensive chemotherapy and surgery. Hematologic and gastrointestinal toxicities are expected but manageable with diligent supportive care. The long-term efficacy of this therapy remains disappointing, thus novel approaches are being investigated.

Desmoplastic small round cell tumor: imaging findings associated with clinicopathologic features

PURPOSE

To describe imaging findings of desmoplastic small round cell tumor (DSCRT) and to clarify the relation between radiologic appearances and clinicopathologic features.

MATERIALS AND METHODS

CT scans and MRI examinations of four male patients with histologically confirmed DSCRT (mean age = 20 years) were retrospectively analyzed.

RESULTS

The common imaging finding was multiple peritoneal masses with regular contour situated within mesentery. Tumors showed central low attenuation in 75% of patients on nonenhanced CT. All tumors showed inhomogeneous enhancement on CT. Small foci of punctate calcification were identified in a part of the tumor in all patients. Bone metastases were identified on enhanced CT in two patients 2 and 8 months after diagnosis, respectively. Pleural dissemination was identified in all patients, and one patient had double-sided dissemination. T2-weighted MRI showed inhomogeneous high signal intensity, and small cysts were identified in two patients. Fluid-fluid levels were identified in six tumors on T2-weighted images, which suggested the presence of hemorrhage. Tumors had inhomogeneous signal intensity low or isointense relative to skeletal muscle on T1-weighted images. Two lesions exhibited inhomogeneous enhancement with central low intensity consistent with necrosis.

CONCLUSION

Imaging studies can depict disseminated characteristics and disease extent during the clinical course of DSRCT.

Tumor de pequenas células redondas desmoplásico intra-abdominal: relato de caso

Os autores relatam um caso de tumor de pequenas células redondas desmoplásico intra-abdominal acometendo paciente do sexo masculino, de 21 anos de idade, atendido com quadro de dor abdominal, trombose do membro inferior direito e perda da função renal, de causa obstrutiva. A investigação demonstrou volumosa lesão abdominopélvica, sólida, bocelada, com áreas císticas internas, situada posteriormente à bexiga, causando obstrução ureteral, compressão da veia ilíaca direita e oclusão parcial do reto, além de acometimento de linfonodos intra e retroperitoneais. São descritos os achados cirúrgicos, de ultra-sonografia, tomografia computadorizada e ressonância magnética, bem como aqueles do estudo macroscópico, microscopia e imuno-histoquímica.

Successful dose-intensive treatment of desmoplastic small round cell tumor in three children

Desmoplastic small round cell tumor (DSRCT) is a rare soft tissue tumor of primitive origin occurring primarily in children and young adults. Based on published reports in the literature, the response to conventional chemotherapy is poor. We report three pediatric patients successfully treated with dose-intensive, multimodal therapy. Between August 1994 and March 1998, we evaluated three consecutive patients with DSRCT at Children's Hospital and Regional Medical Center, Seattle, Washington. We established the diagnosis based on clinical presentation, radiologic staging, and pathologic review with immunohistochemical staining. All patients received a combined modality protocol including dose-intensive chemotherapy (two of them with peripheral blood stem cell [PBSC] support), second look surgery, and consolidative local irradiation. The patients remain in continuous remission at 66, 42, and 26 months after diagnosis, respectively. Two of our patients were younger than any previously reported patient, extending the age group for which DSRCT should be considered on diagnosis of small round cell tumors. The uniform survival achieved in our series indicates potential benefit for the combination of dose-intensive multiagent chemotherapy, local irradiation, and aggressive surgical approach in this disease.

Pathologic, cytologic and immunohistochemical findings of an intra-abdominal desmoplastic small round cell tumor in a 15-year-old male

The intra-abdominal desmoplastic small round cell tumor is a rare neoplasm. It usually occurs in young males and diffusely involves the peritoneum and pursues an aggressive clinical course. The present patient was a 15-year-old male who experienced abdominal pain and abdominal swelling. The patient was diagnosed with an intestinal myogenic sarcoma, and surgery for tumor resection was performed in June 1999. The tumor was a 20 x 15 x 15 cm well-defined mass in the peritoneum involving the transverse colon and stomach with peritoneal disseminations and splenic metastasis. Microscopic findings were well-defined nests composed of small round cells and separated by abundant desmoplastic stroma. Cytologically, the tumor cells consisted of small, round to oval cells with a scant amount of light blue cytoplasm. Immunohistochemically, the tumor cells were positive for anti-epithelial membrane antigen, vimentin, desmin, neuron-specific enolase and WT1 protein antibodies. Similar pathologic features with other small round cell tumors may lead to differential diagnostic difficulties that require the application of ancillary diagnostic methods, such as immunohistochemistry and cytogenetic techniques.