Intra-abdominal desmoplastic small round cell tumors: CT findings and clinicopathological correlations in 13 cases

Imaging Diagnosis of Desmoplastic Small Round Cell Tumor: A Report of Two Cases

Desmoplastic small round cell tumor (DSRCT) is a rare multifocal peritoneal sarcoma, typically found in adolescent and young adult males. Symptoms are nonspecific and vary depending on tumor involvement. Diagnosis is primarily histopathological, although imaging results can assist in the diagnostic process. Although not pathognomonic, certain radiologic findings can help narrow down potential diagnoses and sometimes suggest the condition, as seen in our cases. Treatment options are not well-established or effective, and despite employing various therapeutic approaches, the prognosis remains poor. We present two cases of boys aged 11 and 10 with a final diagnosis of DSRCT, emphasizing the imaging findings.

Desmoplastic Small Round Cell Tumors: A review with focus on clinical management and therapeutic options

Desmoplastic Small Round Cell Tumors (DSRCTs) are an entity of rare, aggressive soft tissue sarcomas described by Gerald and Rosai in 1989. It predominantly affects male adolescents and young adults, with a peak incidence between an age of 20 and 30 years. Typically, DSRCT demonstrate as multiple small tumor nodules within the abdominal cave, retroperitoneum and pelvis. In more than 50% of the cases, the neoplasm presents metastatic at the timepoint of diagnosis. Histologically, DSRCTs have a characteristic morphology with sharply demarcated islands of uniform small round cells in abundant desmoplastic stroma organized in loose extracellular matrix. Immunohistochemistry reveals a polyphenotypic differentiation with co-expression of epithelial, myogenic, mesenchymal and neural markers. The morphology is highly variable and can hinder diagnosis. The most consistent molecular characteristic of DSRCT is the reciprocal t(11;22)(p13q12) translocation. This mutation leads to a formation of the EWSR1-WT1 fusion oncogene, which encodes for a chimeric protein with transcriptional regulatory activity and is regarded as driving source of the disease. To date, there is no standardized concept for clinical management, staging and treatment. Patients receive an aggressive multimodal therapeutic approach consisting of chemotherapy, radical surgical procedures, hyperthermic, intraperitoneal chemotherapy (HIPEC) and radiation. New targeted therapies are used in experimental settings as salvage therapy. So far, none of these therapies showed significant long-term success. This review gives an overview of diagnostic difficulties and pitfalls, discusses therapeutic strategies and highlights options for clinical management.

Sinonasal desmoplastic small round cell tumor: a case report and review of the literature

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare malignancy with poor prognosis that generally involves the peritoneum. Its diagnosis can be achieved only by immunohistochemistry and cytogenetic studies.

CASE PRESENTATION

In the current report, a 55-year-old female was admitted in our hospital for evaluation of right eye epiphora and right nasal intermittent bleeding. Imaging examination revealed a large soft tissue mass in the right nasal cavity and ethmoid sinus. After an explorative surgery, the pathological findings confirmed the presentation of sinonasal DSRCT. Immunohistochemistry and cytogenetic studies confirmed the diagnosis of DSRCT in this patient. Surgical resection, chemotherapy, and radiotherapy was performed, and she died 2 months after operation.

CONCLUSION

This reported case draws attention to the importance of novel treatments and including DSRCT in the differential diagnosis of sinonasal tumors.

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.

Bone Marrow Metastasis of Desmoplastic Small round Cell Tumor

Desmoplastic small round cell tumor is an extremely rare and highly aggressive neoplasm. It usually arises as a single mass or multiple masses in the abdominal cavity, characterized by diffuse peritoneal implants, involvement of regional lymph nodes, and liver and lung metastases. However, bone marrow metastasis has rarely been reported in the literature. We present a case of clinically symptomatic bone marrow metastasis in a 25-year-old woman with a diagnosis of desmoplastic small round cell tumor originating from the pelvic cavity.

3D Bone Tissue Growth in Hollow Fibre Membrane Bioreactor: Implications of Various Process Parameters on Tissue Nutrition

New experimental evidence shows that hollow fibre membrane bioreactor (HFMB) may be applied to grow bulky bone tissues which may then be implanted into patients to repair skeletal defects. To design effective bone tissue engineering protocols, it is necessary to determine the quantitative relationships between the cell environment and tissue behaviour in HFMBs and their relationship with nutrient supply. It is also necessary to determine under what conditions nutritional limitations may occur and, hence, may cause cell death. These require that the appropriate bioreactor conditions for generating neotissues, and the nutrient transfer behaviour and chemical reaction during cell growth and extracellular matrix formation are studied thoroughly. In this paper, we aim to use an existing mathematical framework to analyse the influence of various relevant parameters on nutrient supply for bone tissue growth in HFMB. We adopt the well-known Krogh cylinder approximation of the HFMB. The model parameters (e.g., cell metabolic rates) and operating conditions for the mathematical model have been obtained from, or correspond to, in-house experiments with the exception of a few variables which have been taken from the literature. The framework is then used to study oxygen and glucose transport behaviour in the HFMB. Influence of a number of important process parameters, e.g., reaction kinetics, cell density, inlet concentration of nutrients, etc, on the nutrient distributions have been systematically analysed. The work presented in this paper provides insights on unfavourable system designs and specifications which may be avoided to prevent mass transfer limitations for growing bone tissues in HFMB.

Desmoplastic Small Round Blue Cell Tumor: A Review of Treatment and Potential Therapeutic Genomic Alterations

Desmoplastic small round blue cell tumors (DSRCTs) originate from a cell with multilineage potential. A molecular hallmark of DSRCT is the EWS-WT1 reciprocal translocation. Ewing sarcoma and DSRCT are treated similarly due to similar oncogene activation pathways, and DSRCT has been represented in very limited numbers in sarcoma studies. Despite aggressive therapy, median survival ranges from 17 to 25 months, and 5-year survival rates remain around 15%, with higher survival reported among those undergoing removal of at least 90% of tumor in the absence of extraperitoneal metastasis. Almost 100% of these tumors contain t(11;22) (p13;q12) translocation, and it is likely that EWS-WT1 functions as a transcription factor possibly through WT1 targets. While there is no standard protocol for this aggressive disease, treatment usually includes the neoadjuvant HD P6 regimen (high-dose cyclophosphamide, doxorubicin, and vincristine (HD-CAV) alternating with ifosfamide and etoposide (IE) chemotherapy combined with aggressively attempted R0 resection). We aimed to review the molecular characteristics of DSRCTs to explore therapeutic opportunities for this extremely rare and aggressive cancer type.

Peritoneal Malignancy in Children: A Pictorial Review

Peritoneal malignancies are a rare occurrence in children, often metastatic and rarely originating primarily in the peritoneum. The imaging findings of these entities in the pediatric age have not been recently reviewed or they have been previously described or depicted mostly as part of articles discussing each entity separately. This is a review of the most relevant peritoneal malignancies in childhood emphasizing imaging features. Knowledge of these appearances may facilitate diagnosis and staging of these neoplasms.

Intra-abdominal desmoplastic small round cell tumour: staging and surveillance with 18F-FDG PET/CT following peritonectomy and HIPEC

Intra-abdominal desmoplastic small round cell tumours are rare aggressive tumours of mesothelial origin with less than 60 cases reported in the literature. They are difficult to treat and the role of ¹⁸F-fludeoxyglucose positron emission tomography (PET)/CT scan in their management has not been established. A 41-year-old male presented with a 21-cm desmoplastic small round cell tumour and was managed with radiotherapy, surgery and chemotherapy, with each treatment monitored and guided by ¹⁸F-fludeoxyglucose PET/CT scan. We present the imaging findings of the serial PET/CT scans of this patient and their impact on management.

Intra-abdominal desmoplastic small round cell tumors: CT and FDG-PET/CT findings with histopathological association

Desmoplastic small round cell tumors (DSRCTs) are rare and aggressive malignant tumors. The aim of the present study was to analyze computed tomography (CT) and fluorodeoxyglucose positron emission tomography (FDG-PET)/CT imaging features of intra-abdominal desmoplastic DSRCT, and investigate the association of these features with histopathological results. The present study was a retrospective investigation of 4 patients with DSRCT. All patients underwent CT and dynamic CT, and 1 additionally underwent FDG-PET/CT scanning. Following a tumor resection, routine hematoxylin and eosin staining, and immunostaining, were performed and evaluated. Multiple large abdominopelvic masses were identified in all 4 patients; however, no indications of their site of origin were demonstrated. CT revealed soft-tissue masses with patchy foci of hypodense lesions. Contrast-enhanced CT revealed slightly or moderately heterogeneous enhancement of the lesions. Other observations from these patients included calcification (n=2), peritoneal seeding (n=3), hepatic metastasis (n=3), retroperitoneal lymphadenopathy (n=3) and ascites (n=2). FDG-PET/CT revealed multiple nodular increased FDG uptake in the abdominopelvic masses, and in the liver and peritoneum in 1 case. Intra-abdominal DSRCT demonstrated significant diagnostic characteristics on plain and contrast-enhanced CT. Multiple, bulky soft-tissue masses inside the peritoneal cavity, particularly in male adolescents and young adults, should be considered as potential cases of DSRCT. FDG-PET/CT techniques may be utilized to aid the staging of tumors.

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.

Desmoplastic small-round-cell tumor of the abdomen: A report of two rare cases

Desmoplastic small-round-cell tumor (DSRCT) is an uncommon type of malignancy, which primarily occurs in adolescent males and develops in the abdominal cavity. The present study reports the case of two manifestations of DSRCT complicated with other diseases, which involved the invasion of the pelvis or abdominal vessels. The first case was of a 25-year-old man with repeated diarrhea and abdominal distension for 9 months; the second case was of a 68-year-old man who presented with persistent abdominal pain for 20 days. In each patient, a mass was identified in the abdomen and biopsies were performed in order to reach a diagnosis. Immunohistochemical staining of the biopsy material revealed a diagnosis of DSRCT in each case. In addition, the present study aimed to discuss the use of imaging techniques in providing evidence for the early diagnosis of DSRCT.

Primary malignant tumors of peritoneal and retroperitoneal origin: clinical and imaging features

Peritoneal carcinomatosis and metastatic involvement of the retroperitoneum are manifestations of many organ-based malignancies and lymphoproliferative disorders. Primary malignancies of peritoneal and retroperitoneal origin occur much less frequently, and are difficult to distinguish from metastatic disease on imaging alone. However, the imaging features of these primary tumors, taken in concert with the clinical data, can be helpful in narrowing the scope of the differential diagnosis. This review presents the clinical and imaging features of primary peritoneal and retroperitoneal tumors arising from the various tissue components that comprise the ligaments, mesenteries, and connective tissues of the peritoneal and retroperitoneal spaces.

Removal of an intra-abdominal desmoplastic small round cell tumor by repetitive debulking surgery: A case report and literature review

In the current study, a case of recurrent desmoplastic small round cell tumor (DSRCT) is presented, which was successfully treated by repetitive debulking surgery. In May 2010, a 39-year-old male, with a history of surgical resection of intra-abdominal DSRCT, visited the Ibaraki Medical Center, Tokyo Medical University Hospital (Ami, Japan) with severe lower abdominal discomfort. Abdominal computed tomography revealed a large tumor in the pouch of Douglas with a small number of nodules in the abdominal cavity. The recurrent DSRCT was diagnosed and removed via lower anterior resection; however, complete resection was impossible due to multiple peritoneal metastases. One year later, the patient developed pain in the right groin due to the growth of metastasized tumor cells in the groin lymph nodes. The affected lymph nodes were removed utilizing an extra-peritoneal approach. At the time of writing, the patient continues to survive without any symptoms 60 months since the initial surgery. In conclusion, surgical debulking is a significant procedure for relieving patient symptoms as well as improving the survival time of patients with metastatic and recurrent DSRCT.

Desmoplastic small round cell tumour: the radiological, pathological and clinical features

OBJECTIVES

Desmoplastic small round cell tumours (DSRCTs) are rare aggressive tumours of young adults that present late and have poor prognosis. This review discusses distinctive radiological features, histopathology and clinical course of this soft-tissue sarcoma.

METHODS

From 1991 to 2012, the radiology of 20 patients with pathologically proven DSRCT was independently reviewed by two experienced radiologists. The clinical presentation, treatment and outcome were recorded.

RESULTS

PATIENTS

16 men, four women; mean age 28.3 years. Computed tomography (CT) demonstrated peritoneal/omental masses without an organ of origin (94 %), with the majority of cases demonstrating large (>5 cm) dominant soft-tissue deposit (80 %) with multiple smaller foci. CT and magnetic resonance imaging (MRI) typically demonstrated heterogeneous soft-tissue enhancement with cystic degeneration. A minority (20 %) demonstrated calcification. Lymph node enlargement occurred in 50 % of cases. Distant metastatic disease occurred in 25 %. Painful abdominal masses were clinically predominant. Treatment strategies include combination chemotherapy with debulking surgery and/or radiotherapy. Median survival from diagnosis was 22.8 months.

CONCLUSION

Features of multifocal peritoneal/omental masses, usually in combination with a dominant soft tissue deposit, are distinctive in this rare sarcoma. CT/MRI defines the extent of disease and characterises supporting imaging findings. Prolific desmoplastic reaction histologically separates DSRCT from similar subtypes. Combination treatment strategies can infer a survival benefit but prognosis remains poor. TEACHING POINTS : • DSRCTs are rare tumours of young adults (mean age 28.3 years) with a male predominance (4:1). • Painful abdominal masses clinically predominate. Non-specific features of malignancy can be present. • Multifocal peritoneal masses with a dominant soft tissue lesion is a distinctive imaging finding. • A large desmoplastic reaction differentiates DSRCTs from histologically similar round cell subtypes. • Despite debulking surgery with adjuvant chemotherapy, median survival from diagnosis is 22.3 months.

Peritoneal sarcomatosis in pediatric malignancies

Peritoneal sarcomatosis (PSC) is defined as peritoneal involvement of multiple sarcomatous tumors. Desmoplastic small round cell tumors (DSRCT) and rhabdomyosarcomas are the most common pediatric PSC cases. PSC has been treated with chemotherapy and mainly palliative surgery, but long-term outcome has been poor. New imaging technologies have improved the evaluation of disease extent and patterns of peritoneal dissemination, and cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is being evaluated as a treatment option to prolong remission in pediatric patients. We will review the clinical characteristics, potential biologic mechanisms, radiographic characteristics, and potential therapies for pediatric PSC patients.

Characteristic imaging features of desmoplastic small round cell tumour

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Metastatic desmoplastic small round cell tumor controlled by an anthracycline-based regimen: review of the role of chemotherapy

Desmoplastic small round cell tumors (DSRCT) are rare and aggressive malignant neoplasms that usually occur in young males. They usually present intraabdominally with widespread peritoneal involvement at diagnosis and are sometimes associated with lymphadenopathies and liver metastases. Intraabdominal DSRCT is usually disseminated; no curative outcome has yet been achieved. We report a case of metastatic intraabdominal DSRCT controlled by an anthracycline-based regimen. A literature review of the treatment options, mainly chemotherapy, available for this unusual neoplasm, will be discussed. In patients with unresectable or metastatic disease, symptom control is most important because treatment modalities minimally impact survival. Palliative chemotherapy (mainly monotherapy) is preferable.

CT, MRI, and FDG-PET/CT imaging findings of abdominopelvic desmoplastic small round cell tumors: correlation with histopathologic findings

OBJECTIVE

To analyze computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT imaging features of abdominopelvic desmoplastic small round cell tumor (DSRCT) and to improve the diagnostic efficacy of these techniques for the detection of such tumor.

METHODS

We retrospectively analyzed 7 cases of abdominopelvic DSRCT confirmed by histopathologic analysis. Among the 7 patients, 5 patients had undergone CT scanning, 2 of which were also examined with FDG-PET/CT imaging, and 2 had undergone MRI. Unenhanced and contrast-enhanced examinations were performed in all patients, and 2 patients had also undergone dynamic CT contrast-enhanced examinations. Image characteristics, such as shape, size, number, edge, attenuation, and intensity of each lesion before and after contrast enhancement were analyzed and compared with the pathomorphology of the tumors.

RESULTS

Multiple large masses in the abdominopelvis were detected in 6 cases, and a large mass in the pelvis was detected in 1 case. Six cases showed largest mass in pelvis, and 1 case in mesentery. None of the masses had a definite organ origin. CT showed soft tissue masses with patchy foci of hypodense areas. MR T1-weighted images revealed lesions with mild hypointense areas and patchy hypointense areas in 2 cases and lesions with patchy hyperintense areas in 1 case. T2-weighted images showed lesions with mixed isointense and hyperintense areas in 1 case and lesions with mixed hypointense, isointense, and hyperintense areas in another. Contrast-enhanced CT and T1-weighted images showed mildly heterogeneous enhancement of the lesions. Other associated findings included peritoneal seeding (n=3), peritoneal effusions (n=3), hepatic metastasis (n=2), bone metastasis (n=1), and mesenteric and retroperitoneal lymphadenopathy (n=4). FDG-PET/CT showed multiple nodular foci of increased metabolic activity in the abdominopelvic masses, in the hepatic and right ilium in 1 case and foci of increased metabolic activity in the pelvic mass in another.

CONCLUSION

Radiological findings of DSRCT include multiple masses with heterogeneous density/intensity and without an organ origin. Other common associated findings include peritoneal seeding, peritoneal effusion, hepatic metastasis, and retroperitoneal lymphadenopathy. DSRCT should be considered in the differential diagnosis of regional tumors in adolescents and young adults. FDG-PET/CT can provide additional information on the stage of the tumor.

Intra-abdominal desmoplastic small round cell tumour in a 39-year-old man

Desmoplastic small round cell tumor is a very rare neoplasm, that usually appears in children and young adolescents. There is no standard therapy, and responses to chemotherapy are infrequent. Surgery is still the main treatment for this disease. We report the case of a 39 year-old man and briefly summarize the evidence about this tumor.

Retroperitoneal desmoplastic small round cell tumor: Pediatric patient treated with multimodal therapy

A desmoplastic small round cell tumor (DSRCT) is a rare, aggressive mesenchymal neoplasm. Although a DSRCT can develop at various sites, the intra-abdominal site is the most common location. These tumors are found most commonly among young adolescents and the prognosis is extremely poor. Multimodal treatment with surgery, chemotherapy and radiotherapy is very important for these rare cases, and this treatment can improve patient survival. In this report, we describe the case of an 8-year-old boy diagnosed with DSRCT located in the retroperitoneal space. The patient has undergone surgical resection and adjuvant chemoradiation therapy, and is currently alive without disease recurrence.

[Desmoplastic small round cell tumour of the pancreas with breast metastasis]

Desmoplastic small round cell tumour (DSRCT) is a very rare, highly aggressive neoplasm. Most cases have been reported in adolescent and young male patients. These tumours occur mainly in the peritoneal cavity, with peritoneal and lymphatic dissemination. Their histologic features are unspecific and immunohistochemistry and cytogenetic or biomolecular techniques are required for their diagnosis. Involvement of the pancreas is exceptional and is difficult to differentiate from other pancreatic primary tumours. We report here the case of a 49-year-old woman who had a DSRCT of the pancreas with metastasis to the breast. She died within one year after the diagnosis despite an aggressive surgical strategy.

Intra-abdominal desmoplastic small round cell tumor: an analysis of 4 cases

AIM: To investigate the clinical features of intra-abdominal desmoplastic small round cell tumor (IDSRCT).

METHODS: We retrospectively analyzed 4 cases of IDSRCT in our hospital from June 1996 to October 2006.

RESULTS: All the 4 cases were admitted with symptoms of ascites and/or abdominal mass. The patients underwent exploratory laparotomy, revealing multiple peritoneal and mesenteric masses with an extensive seeding. The diagnosis was made by pathology after operation.

CONCLUSION: IDSRCT is a very rare peritoneal malignant neoplasm, and it is a disease with high metastasis and poor prognosis.