Response to vinorelbine and low-dose cyclophosphamide chemotherapy in two patients with desmoplastic small round cell tumor

We report two cases of abdominal desmoplastic small round cell tumor (DSRCT) that showed a clinical response to the vinorelbine/low-dose cyclophosphamide combination that has been claimed to be effective for rhabdomyosarcoma. This observation may prompt further investigation into the activity of such a regimen in DSRCT patients with recurrent or refractory disease, with a view to a possible future role as maintenance therapy in controlling minimal residual disease in patients who achieve complete remission with intensive induction multimodality therapy.     

Recurrent desmoplastic small round cell tumor responding to an mTOR inhibitor containing regimen

Desmoplastic small round cell tumor (DSRCT) is a rare mesenchymal tumor that typically presents with multiple abdominal masses. Initial treatment is multimodal in nature. Patients with relapsed DSRCT have a poor prognosis, and there are no standard therapies. We report our experience with five patients treated with vinorelbine, cyclophosphamide, and temsirolimus (VCT). Median number of VCT courses delivered was 7 (range 4–14 courses), and partial response was observed in all patients. Median time to progression or relapse was 8.5 months (range 7–16 months). Neutropenia and mucositis were most common toxicities (n = 4 each).     

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 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.     

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.     

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. Pediatr Blood Cancer 2008;51:545–548. © 2008 Wiley‐Liss, Inc.     

Intraabdominal desmoplastic small round cell tumour

Desmoplastic small round cell tumour (DSRCT) is an extremely rare neoplasm. Adolescent males and young adults are most frequently affected. It is highly malignant, with only 29% of patients surviving up to 3 years. This paper documents two cases, one of which, at 4 years old, is the second youngest case documented. Case 1, a 10-year old boy, presented with a 20-day history of choluria, acholia, asthenia, anorexia, and right abdominal pain. Laboratory values were altered, and imaging showed multiples masses in the liver and retroperitoneum. A minilaparotomy was carried out, and a biopsy showed a stage III DSRCT. He was treated with chemotherapy but died of hepatic failure. Case 2, a 4-year-old boy, presented with a 2-month history of abdominal distension. Several hard masses were palpated in the abdomen, and a right inguinal mass that compressed the right testis was observed. Biopsy of the inguinal tumour showed a DSRCT. After treatment with chemotherapy, two operations were carried out to resect different intraabdominal masses. The patient died with peritoneal carcinomatosis 2 months after the last operation. The first patient died due to the advanced stage of the disease, and the second died after chemotherapy, peripheral blood stem transplantation, and multiple operations. The occurrence of this type of tumour in the paediatric age group as well as its high malignancy is noteworthy. Until more effective forms of treatment are found, we recommend treatment with chemotherapy, surgery, and radiotherapy, with close monitoring of the patient.     

Abdominal undifferentiated small round cell tumor with unique translocation (X;19)(q13;q13.3)

We describe a male with a large abdominal mass, most likely originating from the liver, with capsule rupture and tumor dissemination into the abdominal cavity. Adherence of the tumor to the diaphragm and lower right colon also were noted. A comprehensive evaluation of the mass revealed no tumor‐defining histopathologic, immunocytochemical, ultrastructural, cytogenetic, or translocation features. The malignant tumor was found to have a novel translocation (X;19)(q13;13.3), which has not been reported in small round cell tumors of childhood or adults. The final diagnosis rendered was an undifferentiated small round cell tumor of uncertain cell of origin. Pediatr Blood Cancer 2010;54:1041–1044 © 2010 Wiley‐Liss, Inc.     

Immune profiles of desmoplastic small round cell tumor and synovial sarcoma suggest different immunotherapeutic susceptibility upfront compared to relapse specimens

1 Background

Desmoplastic small round cell tumor (DSRCT) and synovial sarcoma are rare tumors with dismal outcomes requiring new therapeutic strategies. Immunotherapies have shown promise in several cancer types, but have not been evaluated in DSRCT and synovial sarcoma. Because the immune microenvironment can provide indications of the inflammatory nature of tumors, immunohistochemical staining is able to assess the tumor immune infiltrates in both tumor types.

2 Procedure

Using tissue microarrays of DSRCT and synovial sarcoma tumor samples, we detected tumoral HLA‐A/B/C, beta‐2‐microglobulin(B2M), and PD‐L1 expression, and quantified tumor‐infiltrating lymphocytes expressing CD4, CD8, CD56, CD45RO, or FOXP3 by immunohistochemistry. We used staining intensity on a scale of 0–3 and percentage of tumor stained to determine HLA, B2M, and PD‐L1 scores. We calculated the cytotoxic T lymphocyte (CTL) target score as HLA score × B2M score/100.

3 Results

In diagnostic samples, we found high HLA and CTL target scores and low PD‐L1 expression with decreased scores in recurrence for both tumor types. We found an increase in CD56⁺ natural killer cells in DSRCT samples from diagnosis to recurrence.

4 Conclusions

We found similar immunostimulatory profiles in DSRCT and synovial sarcoma. Our findings suggest that DSRCT and synovial sarcoma may be amenable to immunotherapies, albeit there was significant heterogeneity. Interestingly, HLA and CTL target scores decreased at recurrence, possibly reflecting immunoevasion. Our findings suggest both tumor types may be amendable to CTL‐based therapies at diagnosis but less so at relapse. Our results support further investigation into the prognostic and predictive value of these findings in a larger dataset.     

Imaging of pediatric abdominal soft tissue tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

This paper provides imaging recommendations for pediatric abdominal tumors that arise outside of the solid viscera. These tumors are rare in children and have been categorized in two groups: abdominal wall and peritoneal tumors (desmoid tumor and desmoplastic small round cell tumor) and tumors that arise from the gastrointestinal tract (gastrointestinal stromal tumor and gastrointestinal neuroendocrine tumor). Authors offer consensus recommendations for imaging assessment of these tumors at diagnosis, during follow-up, and when off-therapy.