Desmoplastic small round cell tumor of the parotid gland-report of a rare case and a review of the literature

Case Report: Differentiating hepatic desmoplastic small round cell tumor from hydatidosis in a school-aged boy: the role of contrast-enhanced and interventional ultrasound

Background

Desmoplastic small round cell tumor (DSRCT) is a rare and highly aggressive malignant neoplasm, typically associated with poor prognosis. It predominantly affects adolescents and young males, with a lower incidence in pediatric populations. Due to its rarity, our understanding of DSRCT remains limited, with only a small number of case reports available. The clinical presentation is often non-specific and varies depending on the extent of tumor invasion. Diagnosis relies primarily on histopathological evaluation through biopsy. Although imaging studies contribute to the diagnostic process, they often lack specificity. Nonetheless, certain imaging features can aid in refining differential diagnoses and assessing disease severity. Moreover, minimally invasive, image-guided tissue sampling plays a critical role in confirming the diagnosis through pathological analysis.

Case presentation

A 7-year-old boy presented with abdominal distension and anorexia, without significant abdominal pain, fever, or jaundice. Physical examination revealed abdominal enlargement with hepatosplenomegaly. Laboratory tests showed abnormal liver function (AST 128 U/L, ALP 648 U/L, GGT 885 U/L) and an elevated CA-125 level (170 U/ml). An abdominal CT scan performed at a local hospital identified multiple round, low-density lesions in the liver, suggestive of echinococcosis. The patient was initially diagnosed with suspected echinococcosis and started on albendazole; however, his symptoms did not improve. Upon further evaluation at our institution, ultrasound imaging revealed multiple thick-walled, hyperechoic lesions in the liver with no significant blood flow signals. Contrast-enhanced ultrasound demonstrated that the solid components of the lesion exhibited significant enhancement during the early arterial phase, with rapid attenuation during the early portal venous phase. A metastatic malignant tumor was suspected, prompting a percutaneous biopsy under real-time enhanced ultrasound guidance. Histopathological examination revealed small round tumor cells infiltrating adjacent tissues. Fluorescence in situ hybridization (FISH) confirmed the diagnosis of DSRCT, based on the presence of an EWSR1-WT1 rearrangement. The patient subsequently underwent multimodal treatment, including chemotherapy and radiation therapy, and achieved disease-free survival at the six-month follow-up.

Conclusions

Traditional ultrasound is a convenient, real-time, non-invasive, and radiation-free diagnostic tool, making it particularly well-suited for the diagnosis, screening, and clinical follow-up of focal liver lesions (FLLs) in pediatric patients. This modality enables real-time evaluation of the number, size, location, and morphology of FLLs while assisting in the differential diagnosis. Moreover, it facilitates the assessment of liver parenchyma involvement and portal vein structures. Color Doppler imaging provides valuable insights into the vascular characteristics of tumors, while contrast-enhanced ultrasound (CEUS) agents allow for real-time observation of dynamic tumor perfusion patterns, further refining differential diagnoses based on perfusion characteristics. Compared to the contrast agents used in CT or MRI-which may require sedation or carry risks of renal injury due to radiation exposure-ultrasound microbubble contrast agents are excreted via respiration and do not require sedation, making them especially suitable for pediatric patients. Additionally, ultrasound-guided biopsy is a well-established and reliable method for diagnosing liver lesions. However, the presence of extensive necrosis and the use of fine-needle biopsy can sometimes limit diagnostic accuracy. Incorporating CEUS before or during percutaneous biopsy can help optimize sampling site selection, thereby reducing the likelihood of false-negative results.

Desmoplastic small round cell tumor of bone revealed by 18F-FDG PET/CT: a case report with literature review

A 50-year-old male presented with neck and shoulder pain. Chest CT and 18F-FDG PET/CT revealed osteolytic bone destruction in the left first rib and thoracic vertebrae with increased FDG uptake. Rib biopsy pathology indicated desmoplastic small round cell tumor (DSRCT).18F-FDG PET/CT can accurately locate the distribution of DSRCT and further guide the location of needle biopsy to assist the DSRCT.

Parotid Gland Tumors: Molecular Diagnostic Approaches

Parotid gland pathology represents a web of differential diagnoses. There are many complex cases that require extensive diagnostic tests for a complete and correct final pathology diagnosis. Currently the official classification of parotid gland tumors extends over more than 40 subtypes. We performed a query of the PubMed database regarding the use of molecular biology tests in performing a better characterization of the tumors in specific cases. By using fluorescence in situ hybridization (FISH), reverse transcription polymerase chain reaction (RT-PCR) or next-generation sequencing, the team managing complex cases can offer a personalized therapeutic solution. We review the molecular differential diagnosis according to published articles in the last 5 years for many types of parotid gland tumors ranging from benign to borderline malign tumors to malign aggressive tumors. Mucoepidermoid carcinoma is a distinct subtype of parotid malignancy that was the subject of a consistent number of articles. However, the molecular biology diagnosis techniques helped more in excluding the diagnosis of mucoepidermoid carcinoma, and probably retrospectively limiting the number of cases with this final diagnosis. In Romania, the molecular biology diagnosis is available only in limited research facilities and should receive more consistent funding that will make it available on a larger scale. The novelty of this scoping review is that we propose an algorithm for molecular differential diagnosis of the tumors that could be encountered in the parotid gland.

Effective Treatment of Anlotinib Combined With Chemotherapy in Children With Desmoplastic Small Round Cell Tumor: A Case Series in a Single-center and Literature Review

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is a highly aggressive primitive sarcoma with a 5-year survival rate estimated at only 15% to 30%. Although few curative treatment options exist, patients are most often treated with a combination of aggressive chemotherapy, radiation, and surgery. Targeted therapy inhibitors of platelet-derived growth factor A, insulin-like growth factor receptor 1, and vascular endothelial growth factor receptor-2, which are almost uniformly overexpressed in DSRCT, have largely failed in clinical trials. Anlotinib is a multitarget receptor tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor 1-3, fibroblast growth factor receptor 1-4, platelet-derived growth factor receptor α/β, c-Kit, and Met. In this study, we presented 3 cases of DSRCT treated effectively with anlotinib combined with chemotherapy.

CASE PRESENTATION

Three children DSRCT patients were enrolled from September 2020 to December 2021 and monitored until August 30, 2022. The clinical data were prospectively studied. The peritoneal cancer index classified all 3 patients as stage IV. After surgery, all 3 patients received anlotinib in combination with chemotherapy and reacted to the medication. For all 3 patients, clinical symptoms were substantially eased, and the size of the masses was reduced. Patient 1 and patient 3's progression-free survival had been extended, and anlotinib was continued as a maintenance medication in the 2 patients who were in good health at the end of the follow-up. Patient 2 died of postoperative complications 1 month after second-stage surgery. The main side effects of anlotinib were fatigue and hypertension. However, its toxicity was controllable and tolerable in children patients.

CONCLUSIONS

This is the first report that anlotinib is effective in children with DSRCT. This report may provide an additional option for the treatment of metastatic DSRCT.

Highlighting the Diversity of Desmoplastic Small Round Cell Tumor: A Case Series

Desmoplastic small round cell tumor (DSRCT) is a rare malignant tumor that occurs mainly in the retroperitoneum of children and young adults. In its prototypical form, DSCRT displays characteristic morphology with nested primitive small round cells in a desmoplastic stroma and a distinctive immunophenotype with polyphenotypic differentiation. However, DSCRT can also exhibit a broader clinical, histologic and immunohistochemical spectrum and, therefore, cause diagnostic difficulties. Given that DSCRT is an aggressive and nearly universally fatal disease, making the correct diagnosis is critically important. Herein, we report three patients with DSRCT and unusual clinical, morphologic or immunohistochemical characteristics, in order to highlight its remarkable diversity and increase awareness of this unusual, distinctive neoplasm.

Deep fibrous histiocytoma of the index finger: a case report

Our patient presented with an elastic soft mass of his left index finger. Hematoxylin and eosin staining showed a high cellular density with spindle-shaped cells in a storiform pattern. Immunohistochemical staining was positive for CD68, factor XIIIa and α-smooth muscle actin, and negative for CD34, STAT6, S100 protein, and desmin.

Desmoplastic Small Round Cell Tumor of the Head and Neck: A Potential Diagnostic Pitfall

Primary desmoplastic small round cell tumor (DSRCT) in the head and neck region is extremely rare. There is limited information about its clinicopathological characteristics, prognosis, and treatment modalities. The purpose of this study is to provide a comprehensive review of DSRCT occurring primarily in the head and neck, to demonstrate its peculiar morphology and immunohistochemical expression, and to address the differential diagnoses. A total of 25 cases were collected after a thorough review of the relevant literature. DSRCT was most frequently reported in the major salivary glands, followed by the eyes. Furthermore, some cases were misinterpreted as poorly differentiated carcinoma, Ewing sarcoma, and olfactory neuroblastoma. Diagnosing DSRCTs in the head and neck can be very challenging due to their rarity in this location, overlapping morphology, and immunohistochemistry. In these cases, following a systemic approach helps to solve diagnostic problems.

Primary desmoplastic small round cell tumor of the submandibular gland: a case report and literature review

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a sporadic, highly malignant tumor with a poor prognosis. The abdomen and pelvis have been reported as the primary localization sites. However, to the best of our knowledge, there are few reports on primary DSRCT in the submandibular gland.

CASE PRESENTATION

We report a case of a 26-year-old Chinese man with a mass in the right submandibular gland. Imaging studies showed a hypoechoic mass in the right submandibular region. Intraoperative pathology revealed that the tumor tissue was composed of small round tumor cells and a dense desmoplastic stroma. On immunostaining, the tumor cells showed markers of epithelial, mesenchymal, myogenic, and neural differentiation. The EWSR1 gene rearrangement was detected by fluorescence in situ hybridization. Based on the overall morphological features and immunohistochemical findings, a final diagnosis of DSRCT was made. The patient was treated with comprehensive anti-tumor therapy mainly based on radiotherapy and chemotherapy.

CONCLUSIONS

DSRCT is an uncommon malignant neoplasm with rare submandibular gland involvement. In this report, we have described a case of DSRCT in the submandibular gland and reviewed the literature on DSRCT over the past 5 years. Considering the importance of differential diagnosis between DSRCT, especially with rare extra-peritoneal involvement, and small round blue cell tumors, a full recognition of the clinicopathological features will help to better diagnose this neoplasm.

Desmoplastic Small Round Cell Tumor of the Submandibular Gland: A Case Report and Literature Review

Desmoplastic small round cell tumor (DSRCT) is a rare and aggressively malignant tumor mostly occurring in the abdominal and pelvic cavity of young patients. However, few cases had been reported concerning DSRCT occurring in the head and neck region. We presented a rare case of DSRCT of the right submandibular in a 25-year-old man. MRI revealed a 3 × 2-cm solid nodule located in the right submandibular, and physical examination showed no other occupying lesion elsewhere. Histologically, the tumor was composed of various-sized small round cell nests, embedded in an abundant desmoplastic stroma. Immunohistochemically, the tumor cells were typically positive for epithelial (CK and EMA), mesenchymal (vimentin and desmin), and neuroendocrine (CD56, NSE, Syn, and CgA) markers, but negative for WT1. Fluorescence in situ hybridization revealed the presence of a break apart involving the Ewing sarcoma (EWS) gene. The patient received chemotherapy and radiotherapy and relapsed after 19 months of follow-up. DSRCT of the submandibular gland is rare, and the diagnosis of this tumor in an uncommon location relies on the histomorphology, immunophenotype, and EWS gene translocation detection. Differential diagnosis including primary salivary gland tumors and the other small round cell tumors needs to be excluded.

Desmoplastic Small Round Cell Tumor with "Pure" Spindle Cell Morphology and Novel EWS-WT1 Fusion Transcript: Expanding the Morphological and Molecular Spectrum of This Rare Entity

Background: Desmoplastic small round cell tumor (DSRCT) is a rare pediatric soft tissue neoplasm composed of small round tumor cells with prominent stromal desmoplasia, polyphenotypic differentiation and EWSR1-WT1 gene fusion. We, herein, present a unique case of DSRCT, exhibiting a pure spindle cell morphology, absence of desmoplastic stroma and showing a novel EWS-WT1 fusion transcript. Methods: A 12-year-old boy presented multiple intra-abdominal, confluent and mass-forming nodules that affected the entire abdominal and pelvic cavities. Results: Histologically, the nodules were composed of spindle cells with scant cytoplasm and oval nuclei arranged into short, intersecting fascicles and set in a scant, non-desmoplastic, stroma. Immunohistochemically, neoplastic cells were stained with vimentin, desmin, WT-1 (C-terminus antibodies) and EMA. Reverse-transcriptase polymerase chain reaction (RT-PCR) analysis showed the presence of an unusual chimeric transcript, composed of an in-frame junction of exon 9 of EWS to exon 7 of WT1, confirming the histological diagnosis of DSRCT. Conclusions: The present case contributes to widen the morphological spectrum of this entity; notably, the additional presence of a novel chimeric fusion transcript contributes to making the present case even more unique. Whether the detection of the above-mentioned fusion transcripts could explain the unusual morphology of the tumor remains to be established.

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: A Rare Location in the Parotid Gland

Desmoplastic small round cell tumor represents an unusual variety of tumors that affects mostly children and young males. In this report we present a case of a desmoplastic small round cell tumor involving the parotid gland of a young male. The tumor was excised, and definitive histology showed features of desmoplastic small round cell tumor confirming the diagnosis.

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

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

A comprehensive diagnosis of a desmoplastic small round cell tumor of unusual location based on fine-needle aspiration cytology: Report of a case arising in the parotid gland and review of the literature

Desmoplastic small round cell tumor (DSRCT) is rare and a highly aggressive neoplasm that typically involves the soft tissues of the abdomen or pelvis in children or young adults, showing a male predilection. Although it can occurs over a wide age range, the peak incidence is in the third decade of life. DSRCT usually shows widespread abdominal serosal involvement, and overall patient survival is poor. On the other hand, extra-abdominal DSRCT is very rare. DSRCT in major salivary glands has been reported, but it is extremely rare. In the majority of reported series diagnosis is made by the histological analysis of FFPE tissues together with immunohistochemistry (IHC) and molecular analysis, particularly the demonstration of chromosomal translocation involving EWSR1. Very few cases have been diagnosed so far by Fine Needle Aspiration (FNA) cytology. Moreover ancillary studies have been performed in all reported cases in FFPE samples. There is still controversy and lack of consensus regarding the suitability of cytological samples especially smears for immunocytochemical (ICC) and fluorescence in situ hybridization (FISH), what makes its standardization difficult. We report a case of a primary DSRCT of parotid gland in a 17-year-old male diagnosed by FNA cytology. The cytomorphological diagnosis was coupled with ICC and FISH analysis performed on stained smears. We emphasize the feasibility and reliability of cytological smears for the application of immunocytochemical and molecular techniques.

Subcutaneous desmoplastic small round-cell tumor: An unusual primary location expanding the differential of superficial round-cell tumors

Desmoplastic small round-cell tumor (DSRCT) is a rare, aggressive malignant tumor, which in the great majority of cases arises at abdominal-pelvic sites. Nevertheless, rare cases of primary extra-abdominal tumors have been reported. In challenging cases, its molecular hallmark, the EWSR1-WT1 reciprocal translocation, can be exploited diagnostically by various molecular techniques. Herein, we report an extremely rare case of primary subcutaneous DSRCT in an effort to raise awareness among our dermatopathology colleagues by expanding the differential of superficial round-cell tumors.

Desmoplastic Small Round Cell Tumor of Parotid Gland: A Rare Entity With Diagnostic Challenge

Desmoplastic small round cell tumor (DSRCT) is a rare malignant mesenchymal neoplasm that typically affects young patients and presents as large intraabdominal masses. We report a rare case of parotid gland DSRCT in a 38-year-old man. The tumor cells were large sized and form irregular nests embedded in abundant desmoplastic stroma. Immunohistochemically, the tumor cells were positive for cytokeratin, GATA3, p40, and p63. Working differential diagnosis included squamous cell carcinoma, myoepithelial carcinoma, hyalinizing clear cell carcinoma, NUT (nuclear protein of the testis) carcinoma, and adamantinoma-like Ewing sarcoma. The characteristic morphologic features and presence of EWSR1-WT1 gene fusion are diagnostic of DSRCT. Salivary gland DSRCT is an exceedingly rare entity, with only 6 cases reported in the literature.

Clinicopathologic and molecular features of intracranial desmoplastic small round cell tumors

Desmoplastic small round cell tumors (DSRCTs) are highly aggressive sarcomas that most commonly occur intra-abdominally, and are defined by EWSR1-WT1 gene fusion. Intracranial DSRCTs are exceptionally rare with only seven previously reported fusion-positive cases. Herein, we evaluate the clinical, morphologic, immunohistochemical and molecular features of five additional examples. All patients were male (age range 6-25 years; median 11 years), with four tumors located supratentorially and one within the posterior fossa. The histologic features were highly variable including small cell, embryonal, clear cell, rhabdoid, anaplastic and glioma-like appearances. A prominent desmoplastic stroma was seen in only two cases. The mitotic index ranged from <1 to 12/10 HPF (median 5). While all tumors showed strong desmin positivity, epithelial markers such as EMA, CAM 5.2 and other keratins were strongly positive in only one, focally positive in two and negative in two cases. EWSR1-WT1 gene fusion was present in all cases, with accompanying mutations in the TERT promoter or STAG2 gene in individual cases. Given the significant histologic diversity, in the absence of genetic evaluation these cases could easily be misinterpreted as other entities. Desmin immunostaining is a useful initial screening method for consideration of a DSRCT diagnosis, prompting confirmatory molecular testing. Demonstrating the presence of an EWSR1-WT1 fusion provides a definitive diagnosis of DSRCT. Genome-wide methylation profiles of intracranial DSRCTs matched those of extracranial DSRCTs. Thus, despite the occasionally unusual histologic features and immunoprofile, intracranial DSRCTs likely represent a similar, if not the same, entity as their soft tissue counterpart based on the shared fusion and methylation profiles.

Primary desmoplastic small round cell tumor of the tibia: PET/CT and MRI presentation of a rare case and review of the literature

Desmoplastic small round cell tumor (DSRCT) was a soft tissue sarcoma of mesenchymal cell origin that typically exhibited a multi-phenotypic pattern of immunohistochemical staining. DSRCT mainly presented in the abdomen sites and primary occurrence in bone was exceptional. In this study, we reported a new case of primary DSRCT of the tibia in a 33-year-old man who had intermittent pain in the left tibia. Radiographs showed transparent lesions in the left upper tibial. MRI revealed a lobular, lytic and ill-identified lesion with adjacent soft tissues swelling of the upper left tibia. CT confirmed notable destruction and wormlike osteolysis of the bone cortex. PET/CT showed a mass of high uptakes, indicating the malignance. He accepted surgical resection with followed multi-agent chemotherapy, containing vincristine, doxorubicin, ifosfamide and etoposide. Clinically and radiologically, the patient did not show any evidence of recurrence or metastasis at 30 months after surgical treatment. Primary osteogenic DSRCT was extremely rare and should be considered in differential diagnosis of bone tumors.