Desmoplastic small round cell tumor in childhood: the St. Jude Children's Research Hospital experience

Kidney Disease in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

Kidney injury is a known late and potentially devastating complication of abdominal radiation therapy (RT) in pediatric patients. A comprehensive Pediatric Normal Tissue Effects in the Clinic review by the Genitourinary (GU) Task Force aimed to describe RT dose-volume relationships for GU dysfunction, including kidney, bladder, and hypertension, for pediatric malignancies. The effect of chemotherapy was also considered.

METHODS AND MATERIALS

We conducted a comprehensive PubMed search of peer-reviewed manuscripts published from 1990 to 2017 for investigations on RT-associated GU toxicities in children treated for cancer. We retrieved 3271 articles with 100 fulfilling criteria for full review, 24 with RT dose data and 13 adequate for modeling. Endpoints were heterogenous and grouped according to National Kidney Foundation: grade ≥1, grade ≥2, and grade ≥3. We modeled whole kidney exposure from total body irradiation (TBI) for hematopoietic stem cell transplant and whole abdominal irradiation (WAI) for patients with Wilms tumor. Partial kidney tolerance was modeled from a single publication from 2021 after the comprehensive review revealed no usable partial kidney data. Inadequate data existed for analysis of bladder RT-associated toxicities.

RESULTS

The 13 reports with long-term GU outcomes suitable for modeling included 4 on WAI for Wilms tumor, 8 on TBI, and 1 for partial renal RT exposure. These reports evaluated a total of 1191 pediatric patients, including: WAI 86, TBI 666, and 439 partial kidney. The age range at the time of RT was 1 month to 18 years with medians of 2 to 11 years in the various reports. In our whole kidney analysis we were unable to include chemotherapy because of the heterogeneity of regimens and paucity of data. Age-specific toxicity data were also unavailable. Wilms studies occurred from 1968 to 2011 with mean follow-ups 8 to 15 years. TBI studies occurred from 1969 to 2004 with mean follow-ups of 4 months to 16 years. We modeled risk of dysfunction by RT dose and grade of toxicity. Normal tissue complication rates ≥5%, expressed as equivalent doses, 2 Gy/fx for whole kidney exposures occurred at 8.5, 10.2, and 14.5 Gy for National Kidney Foundation grades ≥1, ≥2, and ≥3, respectively. Conventional Wilms WAI of 10.5 Gy in 6 fx had risks of ≥grade 2 toxicity 4% and ≥grade 3 toxicity 1%. For fractionated 12 Gy TBI, those risks were 8% and <3%, respectively. Data did not support whole kidney modeling with chemotherapy. Partial kidney modeling from 439 survivors who received RT (median age, 7.3 years) demonstrated 5 or 10 Gy to 100% kidney gave a <5% risk of grades 3 to 5 toxicity with 1500 mg/m2 carboplatin or no chemo. With 480 mg/m2 cisplatin, a 3% risk of ≥grade 3 toxicity occurred without RT and a 5% risk when 26% kidney received ≥10 Gy. With 63 g/m2 of ifosfamide, a 5% risk of ≥grade 3 toxicity occurred with no RT, and a 10% toxicity risk occurred when 42% kidney received ≥10 Gy.

CONCLUSIONS

In patients with Wilms tumor, the risk of toxicity from 10.5 Gy of WAI is low. For 12 Gy fractionated TBI with various mixtures of chemotherapy, the risk of severe toxicity is low, but low-grade toxicity is not uncommon. Partial kidney data are limited and toxicity is associated heavily with the use of nephrotoxic chemotherapeutic agents. Our efforts demonstrate the need for improved data gathering, systematic follow-up, and reporting in future clinical studies. Current radiation dose used for Wilms tumor and TBI appear to be safe; however, efforts in effective kidney-sparing TBI and WAI regimens may reduce the risks of renal injury without compromising cure.

Intra-abdominal desmoplastic small round cell tumor: The European pediatric Soft tissue sarcoma Study Group (EpSSG) experience

BACKGROUND

This study describes the clinical findings of a consecutive series of pediatric and adolescent patients with a diagnosis of intra-abdominal desmoplastic small round cell tumor (DSRCT) prospectively enrolled in European pediatric Soft tissue sarcoma Study Group (EpSSG) protocols: the BERNIE study, the EpSSG MTS 2008 study, and the EpSSG NRSTS 2005 study.

METHODS

Patients aged less than 21 years with a diagnosis of DSRCT arising in the abdomen were included. All trials recommended a multimodal approach including intensive multidrug chemotherapy and loco-regional treatment with surgery and/or radiotherapy whenever possible.

RESULTS

The analysis included 32 cases (median age 13.7 years, male:female ratio 1.5:1). Three patients had localized tumors, seven had regionally disseminated disease, and 22 extraperitoneal metastases. All but one patient received multidrug chemotherapy and 11 had maintenance chemotherapy. Loco-regional treatment consisted of surgery only in seven cases, surgery plus adjuvant radiotherapy in 10, and radiotherapy only in six. Among the 17 cases who had radiotherapy, six had irradiation of the primary site, 10 had whole abdominopelvic radiotherapy plus boost to macroscopic residual disease, and one had irradiation to lung metastases only. With a median follow-up of 76 months (range: 18-124 months), 5-year event-free and overall survivals were 19.7% and 21.0%, respectively. Event-free survival was significantly worse for patients who did not receive loco-regional treatment (p-value .007).

CONCLUSIONS

The study confirmed that the outcome of patients with DSRCT remains dismal and did not improve over recent years despite an intensive multimodal treatment approach.

Desmoplastic small round cell tumor: from state of the art to future clinical prospects

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is an extremely rare and highly aggressive soft tissue sarcoma, presenting mainly in male adolescents and young adults with multiple nodules disseminated within the abdominopelvic cavity. Despite a multimodal approach including aggressive cytoreductive surgery, intensive multi-agent chemotherapy, and postoperative whole abdominopelvic radiotherapy, the prognosis for DSRCT remains dismal. Median progression-free survival ranges between 4 and 21 months, and overall survival between 17 and 60 months, with the 5-year overall survival rate in the range of 10-20%.

AREA COVERED

This review discusses the treatment strategies used for DSRCT over the years, the state of the art of current treatments, and future clinical prospects.

EXPERT OPINION

The unsatisfactory outcomes for patients with DSRCT warrant investigations into innovative treatment combinations. An international multidisciplinary and multi-stakeholder collaboration, involving both pediatric and adult sarcoma communities, is needed to propel preclinical model generation and drug development, and innovative clinical trial designs to enable the timely testing of treatments involving novel agents guided by biology to boost the chances of survival for patients with this devastating disease.

Desmoplastic Small Round Cell Tumors With EWS-WT1 Transcript Expression: Should We Consider Children and Adult Patients Differently?

Desmoplastic small round cell tumor (DSRCT) is an aggressive sarcoma occurring in the young, teenager, and adult populations. The aim of this study is to compare initial tumor presentation, therapeutic management and scalability between pediatric and adult DSRCT patients and investigate the possibility of specific therapeutic approaches. A multicenter retrospective study of 81 Franco-Belgian medical files with DSRCT harboring Ewing sarcoma-Wilm tumor transcript was made. Median age was 17 years (3 to 58) with 42 children (13.5 y [3;17]) and 39 adults (28 y [18;58]). No significant differences were found between the 2 groups regarding initial symptoms and metastasis at diagnosis. The therapeutic approaches were similar for both groups: use of neoadjuvant chemotherapy (78.6% vs. 79.5%, P=1), primary surgery (71.4% vs. 69.2%, P=0.73), adjuvant chemotherapy (54.8% vs. 61.5%, P=0.99), radiotherapy (23.8% and 10.3%, P=0.11) and intraperitoneal chemotherapy (14.3% vs. 2.6%; P=0.11). Median time to recurrence was 12 versus 18 months (P=0.13). Overall survival at 2 years and recurrence free were 46.4% versus 60.1% (P=0.83) and 14.3% versus 16%, respectively (P=0.16). Clinical presentation, initial therapeutics and outcome of DSRCT are equivalent suggesting that similar management should be considered for children and adults with DSRCT.

Intraabdominal and ganglionic desmoplastic small round cell tumor: a case series

Introduction

Desmoplastic small round cell tumor is a rare malignancy with poor prognosis, affecting young male patients. It frequently presents as a large abdominal mass with widespread peritoneal involvement at diagnosis. In late stages, metastases may be present.

Aim

We retrospectively reviewed patient characteristics, presenting symptoms, tumor pathology, treatment, and outcome of four patients with desmoplastic small round cell tumor at our institution.

Cases presentation

The first three cases reported are 32-, 17-, and 30-year-old North African males with intraabdominal desmoplastic small round cell tumor treated by surgery, chemotherapy, and radiation therapy with different follow-ups. The final case is a 16-year-old North African male with ganglionic desmoplastic small round cell tumor but no evidence of a tissue mass. He underwent two lines of chemotherapy with no response. The patient was lost after 2 years of follow-up. In all cases, desmoplastic small round cell tumor was confirmed by presence of t(11,22) (p13,q12) translocation.

Conclusion

Treatment of desmoplastic small round cell tumor is based on multidisciplinary therapy. Despite high-dose chemotherapy, extensive surgical resection, and radiotherapy, desmoplastic small round cell tumor remains lethal.

Multiagent chemotherapy including IrIVA regimen and maintenance therapy in the treatment of desmoplastic small round cell tumor

This study reports the treatment feasibility and efficacy of a novel multiagent intensive treatment program for young patients with desmoplastic small round cell tumor. This small series includes three patients and should be seen as a first suggestion of integration of the dose density and the maintenance chemotherapy concept. The IrIVA regimen (irinotecan, ifosfamide, vincristine, and actinomycin-D) is added-used at a short interval between chemotherapy administrations-at more classic intensive ifosfamide-based regimens. The vinorelbine and low-dose oral cyclophosphamide maintenance therapy is added at the end of conventional chemotherapy to achieve an antiangiogenic effect.

Desmoplastic Small Round Cell Tumor of the Kidney: Report of a Case, Literature Review, and Comprehensive Discussion of the Distinctive Morphologic, Immunohistochemical, and Molecular Features in the Differential Diagnosis of Small Round Cell Tumors Affecting the Kidney

Desmoplastic small round cell tumor (DSRCT) is a rare, highly aggressive neoplasm typically presenting with widespread involvement of the abdominopelvic peritoneum of adolescent males, usually without organ-based primary. Although it is believed to originate from the serous (mainly peritoneal) membranes, intracranial, sinonasal, intraosseous, and other soft tissue sites are also documented. A chromosomal translocation t(11:22)(p13;q12) signature that fuses EWSR1 and WT1 genes results in the production of a chimeric protein with transcriptional regulatory activity that drives oncogenesis. Integration of clinical, morphologic, immunohistochemical, and genetic data is necessary to arrive at the correct diagnosis, especially when the tumor arises in an atypical site. A 15-year-old male presented with hematuria and was found to have a large renal tumor associated with adrenal, liver, lung, and bone metastases. Histopathologic and immunophenotypic features were distinctive for DSRCT. This diagnosis was confirmed by means of fluorescence in situ hybridization and cytogenetic analysis, which documented the pathognomonic t(11;22) translocation, and by reverse transcription polymerase chain reaction on snap-frozen tissue, which revealed the EWSR1/WT1-specific chimeric transcript. Despite high-dose chemotherapy and radiation therapy targeted to a single T11 vertebral metastasis, the disease progressed, and the patient died 4 years after the diagnosis. A search of electronic databases for DSRCT yielded 16 cases of well-documented renal primaries out of around 1570 cases from all sites gathered from the global literature. Desmoplastic small round blue cell tumor and other primary renal tumors considered in the differential diagnosis with DSRCT are discussed.

Desmoplastic Small Round Cell Tumor: Long-Term Complications After Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare intra-abdominal soft tissue sarcoma affecting adolescents and young adults. Cytoreduction, hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), and adjuvant radiotherapy may improve local control. We review our experience with patients who undergo CRS/HIPEC and adjuvant radiotherapy for DSRCT.

METHODS

A retrospective review was performed for patients with DSRCT from 2013 to 2017 who underwent CRS/HIPEC. Clinicopathologic, operative, and outcome data were reviewed.

RESULTS

Ten CRS/HIPEC procedures were performed for nine patients (7 males, 6 Caucasian, median age 19 years (range 10-24)). Four patients presented with extra-abdominal disease; five had liver involvement. The median peritoneal cancer index was 16 (range 5-20). All received neoadjuvant chemotherapy. CCR 0/1 resection was possible in nine patients. Major complications occurred in four with no operative mortalities. All received adjuvant chemotherapy, seven received radiation therapy, and three received stem-cell transplant. All but one patient recurred after treatment. The median recurrence-free and overall survival (OS) were 12 and 45 months (95% confidence interval 35.1-54.9) respectively, with a 3-year OS of 55%. Long-term parenteral nutrition was required in eight for a median of 261 days (range 37-997). Clinically significant long-term complications requiring further surgery included gastroparesis (N = 1), small bowel obstruction (N = 3) and hemorrhagic cystitis (N = 2).

CONCLUSIONS

Multimodal therapy for DSRCT consisting of multiagent neoadjuvant chemotherapy, CRS/HIPEC, adjuvant chemotherapy, and radiation therapy is associated with potential cumulative toxicity. Recurrence after resection is common. Prolonged parenteral nutrition may be necessary, and late gastrointestinal and genitourinary complications may require additional treatment.

Desmoplastic Small Round Cell Tumor: Imaging Pattern of Disease at Presentation

OBJECTIVE

The purpose of this study is to evaluate the clinical, pathologic, and multimodality cross-sectional imaging features of a cohort of 94 patients with desmoplastic small round cell tumor (DSRCT).

MATERIALS AND METHODS

This retrospective study of 94 patients with pathologically verified DSRCT was conducted at a tertiary cancer center between 2001 and 2013. Epidemiologic, clinical, pathologic, and imaging findings were recorded. Tumor size, location, and shape and the distribution pattern of metastases at presentation were analyzed.

RESULTS

DSRCT most often occurred in young patients (median age, 21.5 years; range, 5-53 years), showing a marked predominance in male patients (86 male patients vs eight female patients). Eighty nine-patients (95%) were white (defined in this study as white or Hispanic), four were African American, and one was of Asian descent. Most patients had symptoms, with abdominal pain noted as the most common symptom. At initial presentation, 85 patients (90%) had multifocal disease, nodular disease, diffuse omental and peritoneal disease, or a combination of these conditions. Thirty-eight patients (40%) had diaphragmatic involvement. Thirty-two patients (34%) had liver metastases, and 49 patients (52%) had retroperitoneal involvement in the form of implants, tumoral extension, or nodal involvement. With regard to thoracic findings, 33 patients (35%) had nodal disease, 17 (18%) had pleural effusions, and only two (2%) had lung metastases at presentation. Twelve patients (13%) had calcified lesions.

CONCLUSION

DSRCT is a rare, multifocal peritoneal malignancy with frequently disseminated abdominal disease at presentation. In the abdomen, disease most commonly involves the omentum and peritoneum, followed by the retroperitoneum. The liver is the most common solid visceral metastatic site. A substantial number of patients have diaphragmatic involvement. In the thorax, nodal and pleural involvement is more common than lung involvement.

Desmoplastic small round cell tumor: A nationwide study of a rare sarcoma

BACKGROUND AND OBJECTIVES

Desmoplastic small round cell tumor (DSRCT) is a rare peritoneal surface malignancy. Current research is limited by the scarcity of this disease.

METHODS

Patients with DSRCT were identified in the 2004-2014 NCDB. Factors affecting overall survival (OS) were assessed. Additionally, trends were examined based on the volume of cases treated at individual facilities.

RESULTS

A total of 125 patients were identified with a median age of 21 (IQR 15-27). Six had extra-abdominal disease and 15 (12%) had liver involvement. Median OS was 28 months. Systemic chemotherapy (HR 0.4, P = 0.015) and surgery (HR 0.6, P = 0.047) were associated with reduced mortality. For the 74 patients undergoing surgery, absence of liver involvement and receipt of postoperative chemotherapy were associated with improved OS on univariate analysis. On multivariable analysis, two factors approached significance: adjuvant chemotherapy was associated with a reduced risk of mortality (HR 0.3, P = 0.073) and residual macroscopic disease after resection correlated with increased risk of mortality (HR 5.3, P = 0.071). High-volume facilities (≥5 cases) experienced improved OS (median 59.1 vs 28.8 months), albeit not significantly (P = 0.135), compared to low-volume centers.

CONCLUSION

Despite multimodal treatment, DSRCT is associated with dismal outcomes. Facilities familiar with treating this uncommon disease may experience superior outcomes.

Paratesticular desmoplastic small round cell tumors: A case report and review of the literature

Desmoplastic small round cell tumor (DSCRT) is a rare malignancy most often seen in the abdomen or pelvis of young men. Unfortunately, this disease is usually metastatic at diagnosis and has dismal outcomes. We describe a case of isolated paratesticular DSCRT in a 14-year-old male successfully treated with surgical resection, chemotherapy, and adjuvant radiation, and we present a review of the relevant literature. It appears that isolated, paratesticular DSCRTs have a markedly better outcome than the classic abdominal or pelvic location. We hypothesize that this is due to earlier detection and the relative ease of surgical resection.

Perspectives in Pediatric Pathology, Chapter 25. Testicular and Paratesticular Tumors in the Pediatric Age Group

Testicular tumors in the prepubertal age are relatively rare, representing only 9.4% of the total testicular and paratesticular specimens from a 20-year review performed at a large pediatric hospital [ 1 ]. They account for 1% to 2% of all solid tumors in the pediatric age group, with an annual incidence between 0.5/100 000 and 2/100 000 boys according to Coppes et al [ 2 ] and data from the Prepubertal Testicular Tumor Registry [ 3 ]. Similar to other neoplasms afflicting children, a bimodal age distribution is observed. The first peak is between birth and 3 years of age, and a second one occurs at the onset of puberty, extending to the fourth decade. Reports on their frequency vary because some investigators include the adolescent period, while others do not [ 4 ]. The vast majority of testicular tumors are germ cell neoplasms, accounting for 95% across all ages [ 5 ]. In children, germ cell tumors also predominate, representing 71% of all testicular neoplasms. These include yolk sac tumors (49%), teratomas (13%), seminomas and mixed germ cell tumors (9%), and sex-cord stromal tumors (29%). Malignant potential is significantly lower (less than 70%) in the pediatric age group compared to adults (90%) [ 6 ]. According to Pohl et al, 74% of prepubertal testicular tumors are benign [ 7 ].

Imatinib mesylate in desmoplastic small round cell tumors

AIM

To investigate the possible role of imatinib, an inhibitor of the tyrosine kinase activity of PDGF-R, in desmoplastic small round cell tumor (DSRCT).

PATIENTS & METHODS

From August 2005 to June 2009, DSRCT patients refractory to conventional treatment were enrolled. Patients received imatinib 400 mg daily. Primary end point of this open label, prospective, Phase II trial was objective response rate.

RESULTS

Of the 13 enrolled patients, eight were evaluable for response. Median age was 20 years (range: 9-32). Objective responses at 3 months were: stable disease in one patient and progressive disease in seven patients.

CONCLUSION

Imatinib showed no efficacy in the treatment of DSRCT unresponsive to conventional therapy, despite molecular-based selection of patients.

Molecular Changes Associated With Tumor Initiation and Progression of Soft Tissue Sarcomas: Targeting the Genome and Epigenome

Soft tissue sarcomas are rare, but generally aggressive tumors which disproportionately affect children and young adults. They represent less than 10% of all cancers, but are one of the most frequently diagnosed cancers in pediatric patients. These cancers have a high rate of morbidity and mortality, and their overall incidence has been increasing at an estimated rate of 26% over the last 2 decades. The cause of this increased incidence is unknown but various environmental factors have been implicated. Establishing standard therapeutic strategies is challenging for soft tissue sarcomas as more than 50 different histological subtypes exist, each with their own molecular alterations and clinical characteristics, and this combination of tumor heterogeneity and a limited number of clinical cases make detailed omics level molecular studies particularly challenging. This chapter will focus on the unique genetic and epigenetic changes which characterize these cancers, with an emphasis on translocation-associated sarcomas involving primary gene fusions with the RNA chaperone protein EWSR1. We will highlight current therapeutic approaches and discuss opportunities for targeted molecular therapeutics.

Clinical Characteristics and Outcomes of Pediatric Patients with Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DSRCT) is a rare malignancy that typically affects pediatric and young adult patients. There are limited data on the clinical features of pediatric DSRCT. We selected patients aged 0-21 years reported to the Surveillance, Epidemiology and End Results Program from 1991-2011. We estimated overall survival using Kaplan-Meier approaches and compared outcomes using the log rank test. The median age of the 95 pediatric patients was 15.3 years (range: 0-21). The majority of tumors originated in the abdomen and pelvis (84.4%) and the majority of patients had distant metastasis (72.6%). A minority of patients received radiation (34%). Overall survival at 5 years was poor (18.1%; 95% confidence interval 10.1-27.9%). Radiation therapy was associated with superior survival. Pediatric patients with DSRCT have significant disease burden. Outcomes for children are poor, though patients selected for radiation appear to have improved survival.

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.

Current management of pediatric soft tissue sarcomas

Pediatric soft tissue sarcomas are a group of malignant neoplasms arising within embryonic mesenchymal tissues during the process of differentiation into muscle, fascia and fat. The tumors have a biphasic peak for age of incidence. Rhabdomyosarcoma (RMS) is diagnosed more frequently in younger children, whereas adult-type non-RMS soft tissue sarcoma is predominately observed in adolescents. The latter group comprises a variety of rare tumors for which diagnosis can be difficult and typically requires special studies, including immunohistochemistry and molecular genetic analysis. Current management for the majority of pediatric sarcomas is based on the data from large multi-institutional trials, which has led to great improvements in outcomes over recent decades. Although surgery remains the mainstay of treatment, the curative aim cannot be achieved without adjuvant treatment. Pre-treatment staging and risk classification are of prime importance in selecting an effective treatment protocol. Tumor resectability, the response to induction chemotherapy, and radiation generally determine the risk-group, and these factors are functions of tumor site, size and biology. Surgery provides the best choice of local control of small resectable tumors in a favorable site. Radiation therapy is added when surgery leaves residual disease or there is evidence of regional spread. Chemotherapy aims to reduce the risk of relapse and improve overall survival. In addition, upfront chemotherapy reduces the aggressiveness of the required surgery and helps preserve organ function in a number of cases. Long-term survival in low-risk sarcomas is feasible, and the intensity of treatment can be reduced. In high-risk sarcoma, current research is allowing more effective disease control.

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.

Diagnostic Immunohistochemistry in Cutaneous Neoplasia: An Update

Immunohistochemistry (IHC) is an important adjunct in the diagnosis of neoplastic skin diseases. In addition to the many established IHC markers currently in use, new markers continue to emerge, although their general acceptance and routine application requires robust validation. Here, we summarize the most well-established and commonly used biomarkers along with an array of newer ones reported in the past several decades that either demonstrate or hold high clinical promise in the field of cutaneous pathology. We also highlight recent applications of novel IHC markers in melanoma diagnosis including genetic mutation status markers [e.g. BRAF (v-raf murine sarcoma viral oncogene homolog B) and NRAS (neuroblastoma RAS viral oncogene homolog)] and an epigenetic alteration marker (e.g. 5-hydroxymethylcytosine). We specifically focus on the role of IHC in the differential diagnosis of cutaneous lesions that fall under the following categories: melanoma, epidermal tumors with an intraepidermal epitheliomatous pattern, spindle cell lesions of the dermis, small round blue cell tumors of the dermis, and cutaneous adnexal tumors. While IHC is a valuable tool in diagnostic dermatopathology, marker selection and interpretation must be highly informed by clinical context and the histologic differential diagnosis. With rapid progress in our understanding of the genetic and epigenetic mechanisms of tumorigenesis, new IHC markers will continue to emerge in the field of diagnostic dermatopathology.

Desmoplastic Small Round Cell Tumor (DSRCT): an Unusual Intra-abdominal Tumor

Desmoplastic small round cell tumor (DSRCT) is a rare intra-abdominal tumor commonly seen in adolescents and young adult males. It is an important differential diagnosis in these patients presenting with abdominal masses and/or GI obstruction. The management and prognosis improve if preoperative diagnosis can be established.

Peritonectomy and hyperthermic intraperitoneal chemotherapy as treatment for desmoplastic small round cell tumour

INTRODUCTION

The St George Hospital specialises in peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC) for treatment of intra-abdominal malignancies. Despite performing around 800 peritonectomy and HIPEC procedures, we have rarely encountered desmoplastic small round cell tumours (DSRCT). We present our experiences with DSRCT, and propose peritonectomy and HIPEC as a treatment option for DSRCT.

PRESENTATION OF CASE

This is a case series of 3 cases. The first case was a 26-year-old male who presented with appendicitis which we diagnosed as DSRCT and treated with peritonectomy and HIPEC. The second case was a 14-year-old male referred to our centre for peritonectomy and HIPEC after initial presentation with a pelvic mass and treatment with chemotherapy. The third case was a 21-year-old male referred to our centre for peritonectomy and HIPEC for recurrent DSRCT after previously being treated with neoadjuvant chemotherapy and surgery without HIPEC.

DISCUSSION

DSRCT is a rare, almost exclusively intra-abdominal malignancy, which predominantly affects young males. Survival prognosis remains poor in DSRCT despite conventional treatment with surgery, chemotherapy and radiotherapy; however, HIPEC has offered promising survival results. Our recurrences with peritonectomy and HIPEC at 6 months and 15 months are comparable with the literature of 8.85 months.

CONCLUSION

In our experience, patients with DSRCT who present with nodal involvement or recurrent disease tend to recur early despite treatment with peritonectomy and HIPEC. Longer term follow up of our patients and future studies involving HIPEC in DSRCT would be useful in assessing long-term clinical outcomes and survival.

Incidence and outcomes of desmoplastic small round cell tumor: results from the surveillance, epidemiology, and end results database

Desmoplastic small round cell tumor (DSRCT) is a rare but highly fatal malignancy. Due to the rarity of this neoplasm, no large population based studies exist. Procedure. This is a retrospective cohort analysis. Incidence rates were calculated based on sex and ethnicity and compared statistically. Gender-, ethnicity-, and treatment- based survival were calculated using the Kaplan-Meier method. Results. A total of 192 cases of DSRCT were identified. Peak incidence age was between 20 and 24 years. Age-adjusted incidence rate for blacks was 0.5 cases/million and for whites was 0.2 cases/million (P = 0.037). There was no statistically significant difference in survival based on gender or ethnicity. When adjusted for age, there was no statistically significant difference in survival amongst patients who received radiation therapy compared to those who did not (HRadj = 0.73; 95% CI 0.49, 1.11). There was a statistically significant survival advantage for patients who received radiation after surgery compared to those who did not (HR 0.49; 95% CI 0.30, 0.79). Conclusion. DSRCT is more common in males and in people of African-American descent. Although overall survival remains poor, radiation therapy following surgery seems to improve outcome in these patients.

Autologous haematopoietic stem cell transplantation following high-dose chemotherapy for non-rhabdomyosarcoma soft tissue sarcomas: a Cochrane systematic review*

OBJECTIVES

We conducted a systematic review to compare the efficacy and adverse events of autologous haematopoietic stem cell transplantation (HSCT) following high-dose chemotherapy (HDCT) versus standard-dose chemotherapy (SDCT) in patients with locally advanced or metastatic non-rhabdomyosarcoma soft tissue sarcomas (NRSTS).

SETTING

Patients were observed in hospital units specialised for cancer therapy.

PARTICIPANTS

The review evaluated 294 patients with 19 different subtypes of malignant NRSTS. The patients had a median age between 10 and 46 years (range 2-65) and were mostly men.

PRIMARY AND SECONDARY OUTCOME MEASURE

The planned and measured primary outcomes were overall survival and treatment-related mortality. The planned and measured secondary outcomes were progression-free survival, grade 3-4 non-haematological toxicity and secondary neoplasia. Other secondary outcomes including disease-free survival, event-free survival and health-related quality of life were not reported.

RESULTS

We included 62 studies reporting on 294 transplanted patients. We identified 1 randomised controlled trial (RCT) with 38 transplanted and 45 non-transplanted patients and judged a low risk of bias. We further identified 61 single-arm studies with 256 transplanted patients. Overall survival in the RCT was reported not statistically significantly different between autologous HSCT following HDCT versus SDCT. The HR was 1.26 (95% CI 0.70 to 2.29; p=0.44) and the point estimates at 3 years were 32.7% vs 49.4%. Data from single-arm studies were used to extract data on adverse events. Treatment-related mortality was reported in 5.1% (15 of 294) transplanted patients.

CONCLUSIONS

Overall survival in patients with locally advanced or metastatic NRSTS was not statistically different after autologous HSCT following HDCT compared with SDCT in a single RCT with a total of 83 patients. No other comparative study was available. The proportion of adverse events among the transplanted patients is not clear.

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.

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.

Paratesticular desmoplastic small round cell tumour: an unusual tumour with an unusual fusion; cytogenetic and molecular genetic analysis combining RT-PCR and COBRA-FISH

Desmoplastic small round cell tumour is a rare malignant tumour with a male to female ratio of 4:1. It manifests mostly at serosal sites. Here we present a case of a 28-year-old male patient, who presented with a fast growing paratesticular mass. On biopsy nests and cords of small round cells, without a clear morphological lineage of differentiation were seen. Occasionally desmoplatic small round cell tumour shows different lines of differentiation. An unequivocal histological diagnosis might be difficult in such cases. Here we demonstrate by a combination of methods the characteristic immunohistochemical profile and - albeit unusual - molecular background and discuss the eventual link with Ewing sarcoma.Immunohistochemical studies showed a membranous staining of Keratine AE1/3 and a dot-like staining of Desmine, confirming its diagnosis. Using COBRA-FISH following a metaphase approach we demonstrated a balanced translocation, t(11;22)(p13;q12) and in RT-PCR formation of the EWSR1-WT1 fusion product, a specific translocation of desmoplastic round cell tumour. The fusion involves exon 9 of EWSR1 to exon 8 of WT1, an unusual fusion product, though earlier described in a case of a desmoplastic small round cell tumour of the hand. The EWSR1-WT1 chimera seems to function as an oncogenic transcription factor. Here the zinc finger domain of the WT1 acts with affinity with certain promoter domains influencing the expression of various downstream proteins such as: PDGFA, PAX2, insulin-like growth factor 1 receptor, epidermal growth factor receptor, IL2 receptor beta, BAIAP3, MLF1, TALLA-1, LRRC15 and ENT. We discuss their potential oncogenic roles and potential therapeutic consequences.

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.

Analysis of prognostic factors of pediatric-type sarcomas in adult patients

OBJECTIVE

Pediatric-type sarcomas such as Ewing's sarcoma (EWS)/primitive neuroectodermal tumor family and rhabdomyosarcoma are relatively uncommon in adult patients. Optimal treatment strategies for this population and prognosis in adult patients compared with pediatric patients remain controversial.

METHODS

We retrospectively reviewed pediatric-type sarcoma patients older than 15 years at a single institution.

RESULTS

A total of 84 consecutive patients between 1995 and 2009 were identified at the Samsung Medical Center, Seoul, Korea. Median age was 30 years with a range of 15-74 years. Forty-seven patients (56.0%) were diagnosed with Ewing's sarcoma/primitive neuroectodermal tumor family, 34 (40.5%) with rhabdomyosarcoma and 3 (3.6%) with desmoplastic round-cell tumor. Median follow-up duration was 5.9 years. Median overall survival for all patients was 33.1 months (95% CI 13.5-52.7) and median event-free survival for all patients was 14.4 months (95% CI 5.9-22.9 months). Multivariate analysis revealed that localized disease was a significant independent prognostic factor for longer overall survival (hazard ratio 0.30, 95% CI 0.14-0.66, p = 0.003), and favorable primary tumor sites were associated with longer event-free survival (hazard ratio 0.33, 95% CI 0.11-0.98, p = 0.045).

CONCLUSION

We identified the prognostic variables which may facilitate risk-adapted therapies for this rare adult sarcoma group, which should be further investigated.

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.

Symptomatic hypoglycemia related to inappropriately high igf-ii serum levels in a patient with desmoplastic small round cell tumor

A 45-year old man was diagnosed with desmoplastic small round cell tumor (DSRCT) with involvement of the peritoneum and pelvis. Disease progression was observed despite systemic chemotherapy. Six months after diagnosis, he developed severe hypoglycemia presented with seizures. He received intravenous glucose infusion and hydrocortisone with poor glycemic control, but with seizures resolution. The investigation excluded insulinoma, adrenal, liver and GH deficiencies. Laboratory showed slight rise of IGF-II and significant increase of the ratio IGF-II : IGF-I, which is pathognomonic of non-islet cell tumor hypoglycemia (NICTH). He received the diagnoses of NICTH related to IGF-II inappropriate production by DSRCT. Despite the attempt to control tumor mass and hypoglycemia, the patient died 9 months after diagnosis. NICTH related to inappropriate IGF-II secretion should be investigated in all cancer patients with refractory hypoglycemia whom insulinoma and other metabolic abnormalities were excluded from.

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.

Sequential intensified chemotherapy with stem cell rescue for children and adolescents with desmoplastic small round-cell tumor

The RMS4.99 study was designed to explore the role of early sequential intensified chemotherapy (SICT) with PBSC rescue in patients with soft tissue sarcoma with a poor prognosis. Fourteen patients with desmoplastic small round-cell tumor (DSRCT) were included in this study. Initial chemotherapy was followed by a course of CY and etoposide with subsequent PBSC harvest, then three consecutive intensified chemotherapy combinations followed by PBSC rescue and G-CSF administration: first cycle thiotepa (150 mg/m(2) x 2 on day 1) and melphalan (60 mg/m(2) on day 2), second cycle CY (2 g/m(2) on days 1 and 2) and thiotepa (150 mg/m(2) x 2 on day 3), third cycle melphalan (80 mg/m(2) on day 1). The interval between cycles had to be kept as short as possible. Then patients underwent surgery or radiotherapy or both, after which six courses of vincristine, actinomycin D, CY were administered. Ten patients received SICT, which was well tolerated. With a median follow-up of 27 months only three patients are alive without evidence of disease. The 3-year event-free and overall survival rates were 15.5 and 38.9%, respectively. The prognosis for pediatric patients with DSRCT did not improve after administering intensified chemotherapy early in their treatment, so different strategies are needed.

Desmoplastic small round cell tumor: impact of F-FDG PET induced treatment strategy in a patient with long-term outcome

The desmoplastic small round cell tumor (DSRCT) is an uncommon and highly aggressive cancer. The role of ¹⁸F-FDG PET in management of DSRCT is little reported. We report a case of metastasized abdominal DSRCT detected in a 43-year old patient whose diagnostic and therapeutic approaches were influenced by ¹⁸F-FDG PET-CT. The patient is still alive ten years after diagnosis. ¹⁸F-FDG PET-CT seems to be a useful method for assessing therapeutic efficiency and detecting early recurrences even in rare malignancies such as DSRCT.

[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.

Intracerebral small round cell tumor: an unusual case with EWS-WT1 translocation

Desmoplastic small round cell tumor (DSRCT) is a rare tumor, seen both in children and young adults with a marked predilection for the peritoneal cavity. Histology showed a small round cell tumor with a fibromyxoïd stroma and immunohistochemistry indicated neural and mesenchymal differentiation, and diagnosis was made by molecular detection of the EWS-WT1 fusion gene product. DSRCT should be considered in the differential diagnosis of intracranial small round cell tumors.

Outpatient and home chemotherapy with novel local control strategies in desmoplastic small round cell tumor

Desmoplastic Small Round Cell Tumor (DSRCT) has a very poor prognosis. This report illustrates novel chemotherapy and local control interventions in a 5-year old patient. The patient was treated in the outpatient setting, achieved remission, with excellent quality of life. The patient presented with massive ascites and >1000 abdominal tumors. Neoadjuvant chemotherapy included vincristine (1.5 mg/m(2)), ifosfamide (3 g/m(2)/day x 3), dexrazoxane/doxorubicin (750/75 mg/m(2)), and etoposide (150 mg/m(2)). Continuous hyperthermic peritoneal perfusion (CHPP) with cisplatin (100 mg/m(2)) was given after extensive cytoreductive surgery. This was followed by irinotecan (10 mg/m(2)/day x 5 x 2 weeks) + temozolomide monthly x 2, then abdominal radiation 30 Gy with simultaneous temozolomide (100 mg/m(2)/day x 5). A total of 12 cycles of irinotecan and temozolamide were given. Except for initial chemotherapy, subsequent courses were in the outpatient setting. Focal retroperitoneal relapse at 18 months was treated with IMRT with bevacizumab (5 mg/kg) and 2 perihepatic metastases with radio frequency ablation/cryoablation followed by chronic outpatient maintenance chemotherapy (valproic acid, cyclophosphamide, and rapamycin). Almost 2 years from diagnosis, the patient maintained an excellent quality of life. This is a novel approach to the treatment of children with massive abdomino-pelvic DSRCT.

Mesenchymal neoplasms of the major salivary glands: clinicopathological features of 18 cases

Non-lymphoid mesenchymal neoplasms of salivary gland origin are rare, accounting for 1.9-5% of major salivary gland tumors. We describe the clinico-pathologic features of 18 cases of mesenchymal neoplasms of the major salivary glands experienced at Asan Medical Center, Seoul, Korea, from 1998 to 2004. Mesenchymal neoplasms accounted for 3.4% of the total of 524 major salivary gland tumors. The parotid gland was the preponderant site (15 cases). Thirteen tumors were benign, constituting 3.5% of the total of 371 benign neoplasms. Schwannomas were the most common benign tumors (six cases), followed by lipomas (three cases), plexiform neurofibroma, hemangioma, desmoid tumor, and solitary fibrous tumor (one each). The malignant tumors consisted of one dermatofibrosarcoma protuberans, synovial sarcoma, leiomyosarcoma, pleomorphic liposarcoma and desmoplastic small round cell tumor each. Immunohistochemical analysis for the expression of vimentin, actin, desmin, neuron-specific enolase, keratin, CD34, CD99 and bcl-2 contributed to the differential diagnoses. Genetic analysis for fusion transcripts was conclusive in the diagnosis of desmoplastic small round cell tumor, which is extremely rare at this location. Pre-operative imaging study and fine needle aspiration cytology had limitations in prediction of the mesenchymal nature of the tumors, due to either low index of suspicion, similarities to mixed tumors, or specimen inadequacy. Awareness of the development of various mesenchymal tumors in the major salivary glands could increase the accuracy of preoperative and postoperative diagnosis, and therapeutic efficacy.