Cytology of desmoplastic small round cell tumor

Desmoplastic Small Round Cell Tumor Involving Serous Fluid: Cytologic Features and Diagnostic Pitfalls: A Series of 8 Cases

OBJECTIVES

When desmoplastic small round cell tumor (DSRCT) is present in serous fluid, the cytomorphology can be diverse and can mimic metastatic carcinomas and thus present a diagnostic challenge. The aim of this study was to evaluate the cytomorphologic and immunocytochemical features of this rare tumor in serous effusion specimens.

METHODS

Demographic, clinical, radiologic, and pathologic information from patients who had a DSRCT diagnosis on body fluid specimens was collected and cytologic slides were reviewed.

RESULTS

Nine specimens were identified (5 pleural fluid and 4 ascitic fluid specimens) from 8 patients (5 male and 3 female). The mean patient age at diagnosis was 26 years. The most common symptoms were abdominal distension and pain, with 5 patients having abdominal masses. Other findings included peritoneal carcinomatosis, liver masses, ascites, and pleural nodules. The predominant cytomorphology was loose cellular clusters, followed by tight clusters of small cells with scant occasional vacuolated cytoplasm and a sphere-like pattern.

CONCLUSIONS

Serous fluid may be the first available specimen to diagnose DSRCT. In young patients with no history of malignancy and radiologic finding of peritoneal implants, DSRCT should be considered a possibility in the differential diagnosis, and sensitive markers should be used for accurate diagnosis.

A Review of Effusion Cytomorphology of Small Round Cell Tumors

BACKGROUND

Small round cell tumors (SRCTs) are a broad category of diverse malignant tumors composed of monotonous undifferentiated cells. Involvement of serous fluids by SRCT is rare; however, the identification of exfoliated malignant cells is a crucial component of management and has significant implications for treatment and prognosis. The most common effusion tumors with SRCT morphology include Ewing sarcoma, synovial sarcoma, rhabdomyosarcoma (RMS), small-cell neuroendocrine carcinoma (SCNC), and desmoplastic SRCT, and the cytomorphologic distinction between these tumors is challenging. The purpose of this article is to describe the morphologic features of the most common SRCT in fluids and propose helpful ancillary testing.

SUMMARY

Effusion SRCTs display similar primitive and undifferentiated morphologic features although each has subtle variations. Ewing sarcoma is a mesenchymal neoplasm and harbors characteristic translocations t(11;22) (EWSR1-FLI1) or t(21;22) (EWSR1-ERG). In fluids, Ewing sarcoma shows poorly differentiated cells of variable size with round to oval nuclei, prominent nucleoli, and scant cytoplasm. In contrast, synovial sarcoma typically involves extremities and expresses a fusion transcript in t(X;18) (SS18-SSX). This soft tissue neoplasm demonstrates uniform cells with irregular nuclear contours, characteristic nuclear folding, and scant cytoplasm. RMS is a neoplasm arising from skeletal muscle, and the alveolar subtype demonstrates a translocation in t(2;13) (PAX3-FOXO1). The malignant cells show a spectrum of small round cells and pleomorphic large cells with rhabdoid morphology. RMS cells characteristically express myogenin and MyoD1, markers of skeletal muscle differentiation. Although SCNC is not a classic SRCT, the morphology is similar. SCNC demonstrates tight clusters of malignant cells with nuclear molding and salt-and-pepper chromatin. This tumor classically has neuroendocrine differentiation and is positive for synaptophysin and chromogranin on immunohistochemistry. And last, desmoplastic SRCT typically presents as an intra-abdominal mass in young men and characteristically harbors the translocation t(11;22) (p13;q12) (EWSR1-WT1). Cytomorphologically, the tumor shows small monomorphic cells occasionally arranged as rosette-like structures.

KEY MESSAGE

The diagnosis of SRCT can be made in effusion samples and is best achieved with a combination of morphologic features, clinical history, and ancillary testing.

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.

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.

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.

Cytologic diagnosis of round cell sarcomas in the era of ancillary testing: an updated review

Round cell sarcomas constitute a large proportion of "small round blue cell tumors," which encompass a broad differential diagnosis and can be difficult to distinguish on cytomorphologic grounds alone. Numerous pathogenetic insights and advances in ancillary testing in soft tissue pathology over the last several decades have made accurate classification of soft tissue neoplasms increasingly feasible. Immunohistochemistry and genetic/molecular testing can now be performed on all cytologic preparations, including unstained smears, needle rinses, cell blocks, and liquid-based preparations, and this has greatly increased our diagnostic abilities. Nevertheless, there remain numerous diagnostic challenges, including variable sensitivity and specificity of available immunohistochemical markers, overlapping immunophenotypes between entities, and "promiscuity" of genetic alterations such as EWSR1 rearrangements, present in a multitude of tumor types. Herein we provide a review on the cytologic, immunohistochemical, and genetic features of the more frequently encountered round cell sarcomas, as well as recently described entities, with an emphasis on diagnostic pitfalls and judicious use of ancillary studies.

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.

Small cell mesothelioma: A rare entity and diagnostic pitfall mimicking small cell lung carcinoma on fine-needle aspiration

Small cell mesothelioma (SCM) is an extremely rare variant of epithelioid mesothelioma that can be mistaken for other forms of small round blue cell tumors, particularly small cell lung carcinoma (SCLC). Here, we describe a fine-needle aspiration (FNA) from a pleural lesion in a 75-year-old man with a history of known asbestos exposure. The FNA revealed cohesive clusters of uniform small round blue cells with high nuclear-to-cytoplasmic ratio, finely powdery chromatin, small inconspicuous nucleoli, and scant amount of cytoplasm. Mitoses were infrequent and nuclear molding was absent. Immunochemical profile supported a mesothelial origin, which was later confirmed by pleurectomy with a diagnosis of SCM. This report demonstrates the difficulties in cytologic evaluation of lung FNAs in differentiating SCM from SCLC or other small round blue cell tumors. As therapy differs for SCM, early recognition of the cytologic features is essential in making the correct diagnosis needed for appropriate clinical management. Diagn. Cytopathol. 2016;44:526-529. © 2016 Wiley Periodicals, Inc.

Desmoplastic Small Round Cell Tumor, a "Floating Island" Pattern in Pleural Fluid Cytology: A Case Report and Review of the Literature

Desmoplastic small round cell tumor (DSRCT) is a rare aggressive sarcoma with characteristic clinical and pathologic features. It typically involves pelvic and abdominal organs of young male patients, and patients usually present at advanced stage with poor prognosis. A few reports are available describing the cytopathologic features of DSRCT in serous effusions, with the majority of published cases depicting undifferentiated small blue cells that need to be distinguished from other small blue cell tumors. We report an interesting case of DSRCT involving a pleural effusion with a “floating island” pattern that has been described in hepatocellular carcinoma, renal cell carcinoma, and adrenal cortical carcinoma. In our case, the epithelioid tumor cells form cohesive aggregates surrounded by a single layer of spindle cells, mimicking the “endothelial wrapping” in other tumors with “floating island” patterns. We demonstrate, by ancillary testing, that these peripheral spindle cells are tapered/flattened DSRCT cells, in contrast to endothelial wrapping cells, as seen in other tumors with this unique cytomorphology. To our knowledge, this is the first case report describing DSRCT showing a “floating island” pattern that needs to be differentiated from metastatic hepatocellular carcinoma, renal cell carcinoma, and adrenal cortical carcinoma in effusion cytology.

Unusual morphology of desmoplastic small round cell tumor from an ascitic fluid in the postchemotherapy setting

Desmoplastic small round cell tumor (DSRCT) is a malignant neoplasm that most often presents in male adolescents as an abdominal mass. Cytological features have been previously described, but only two reports noted post chemotherapy changes on effusions. We report a case of a 15-year-old male with DSRCT status postchemotherapy that presented with ascitis. Unusual morphology was seen: Numerous malignant large and single cells with prominent nucleoli and abundant cytoplasm in a background without the stroma, occasional mitosis, and the abundant apoptosis. Cell block immunocytochemistry was confirmatory. Awareness of the postchemotherapy changes in this tumor will allow us to diagnose recurrence.

Fine-needle aspiration in desmoplastic small round cell tumor: a report of 10 new tumors in 8 patients with clinicopathological and molecular correlations with review of the literature

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare round cell sarcoma entity characterized by a specific t(11;22)(p13;q12) translocation, usually intra-abdominal localization and an aggressive clinical outcome. To date, only 35 DSRCT cases diagnosed by fine-needle aspiration have been described.

METHODS

This study reports the cytological diagnosis of DSRCT. Ten tumors from 8 patients were sampled for diagnosis and analyzed to search the characteristic translocation using fluorescence in situ hybridization or reverse transcription polymerase chain reaction methods.

RESULTS

Smears were always hypercellular and consisted of nonspecific round cell sarcoma. Nuclei were polymorphic round, kidney-, or heart-shaped. Nuclear molding was usually present. Paranuclear cytoplasmic densities were obvious and noted in 7 cases. Cytonuclear atypia, mitotic figures, numerous crushed nuclei, and apoptosis were frequently seen. Purple-stained stroma was present in 8 cases (ranging from few connective tissue fragments to large hyalinized deposits). Molecular studies based on cytological aspirates were performed in 8 patients. The presence of the fusion gene EWSR1-WT 1 transcript was identified in all, which confirmed the diagnosis of DSRCT.

CONCLUSIONS

Smears showing poorly differentiated round cells associated with cytoplasmic densities and connective stoma, in a specific clinical context, young adult age, intra-abdominal localization, suggestive immunocytochemical profile, and a unique cytogenetic abnormality are highly specific and allow an accurate diagnosis of DSRCT.

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.

Malignant small round cell tumors

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

Desmoplastic small round cell tumour in a 74 year old man: an uncommon cause of ascites (case report)

A rare case is provided of a 74 year old man who presented with ascites of unknown etiology. CT scan of the abdomen revealed extensive omental caking, and omental biopsy cytogenetics showed findings in keeping with a diagnosis of desmoplastic small round cell tumour (DSRCT). This case is unique in that it involves a significantly older patient, negative WT1 immunohistochemical staining, and negative cytology. Despite repeated paracenteses and fluid management, the patient died in hospital secondary to renal complications.

[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.

Desmoplastic small round cell tumor: a clinical, pathological, and immunohistochemical study of 18 Chinese cases

Desmoplastic small round cell tumor (DSRCT) was first reported in 1989. Generally, DSRCT is considered to be an aggressive malignant neoplasm that mainly occurs in the abdominal cavity and has been often seen in adolescents and young male adults. In the present study, a total of 18 cases of DSRCT reported in China between October 1998 and June 2006, including one case treated by the authors, were reviewed and analyzed. Among them, 14 had tumors in the abdominal cavity; the other four cases had tumors in the left fossa orbitalis, the root of the tongue, the soft tissue behind the left eyeball, and the abdominal wall (umbilicus). Overall, the 1-year, 3-year, and 5-year survival rates were 52.36%, 27.92%, and 27.92%, respectively. The survival rate of DSRCT patients is disappointing; however, the survival of patients who had resection of the tumor or received comprehensive clinical treatment is satisfactory.

Imprint cytology of high-grade immature ovarian teratoma: a case report, literature review, and distinction from other ovarian small round cell tumors

Immature ovarian teratoma (IOT) is a rare and aggressive malignant neoplasm characterized by immature neural tissue. The cytomorphologic features have only rarely been described. We herein describe an additional case and review the literature regarding this entity. To the best of our knowledge, this is the first reported case with imprint cytology. A 35-year-old woman presented with a pelvic mass which was resected and sent for frozen section evaluation. Imprint smears and frozen section of the mass were diagnostic of IOT. IOT has diagnostic cytologic features which show complete concordance with histology. Differential diagnoses include other small round cell neoplasms such as ovarian neuroblastoma, small cell carcinoma of hypercalcemic type, primitive neuroectodermal tumor, Wilm's tumor, desmoplastic small round cell tumor, and Non-Hodgkin lymphoma. Distinguishing IOT from these tumors can be challenging however if diligent morphologic study and/or ancillary studies are performed accurate diagnosis is possible.

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

INTRODUCTION

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cytologic diagnosis of Ewing sarcoma/peripheral neuroectodermal tumor with paired prospective molecular genetic analysis

BACKGROUND

Ewing sarcoma/peripheral neuroectodermal tumor (EWS/PNET), since its characterization immunophenotypically and cytogenetically, has emerged as one of most common sarcomas of childhood. Currently, it is recognized that EWS/PNET can occur in any number of extraosseous sites and is one of several distinctive tumor types with an EWS translocation. In the past, the pathologic diagnosis of EWS/PNET relied on an open biopsy with the application of various ancillary studies, ranging from periodic acid-Schiff stain to molecular testing, but the tumor increasingly is diagnosed on the basis of cytologic specimens alone.

METHODS

The authors report 3 cases of EWS/PNET in patients aged 11 years to 53 years. These 3 patients had tumors that involved the parotid gland, cervical soft tissue, and pelvis, and were diagnosed by cytologic evaluation of fine-needle aspiration (FNA) biopsy material alone. The FNA materials also were evaluated prospectively by fluorescence in situ hybridization and/or reverse transcriptase-polymerase chain reaction.

RESULTS

The results emphasized the diagnostic utility of FNA biopsy material for morphologic and molecular analysis without compromising conventional cytologic and immunocytochemical analysis, and that prospective molecular testing of FNA specimens has utility in routine practice although it is subject to many of the same limitations that impact molecular analysis when applied to conventional tissue biopsy specimens.

CONCLUSIONS

The current results demonstrated that molecular genetic techniques can provide clinically useful ancillary information for FNA specimens when cytologic features and/or immunophenotype are equivocal on the basis of limited sampling or secondary changes, such as hemorrhage and/or necrosis.

Cytology of desmoplastic small round-cell tumor: comparison of pre- and post-chemotherapy fine-needle aspiration biopsies

BACKGROUND

Desmoplastic small round-cell tumor (DSRCT) is an aggressive malignancy of young adults, which is amenable to fine-needle aspiration biopsy (FNAB). As this entity is increasingly recognized and biopsied, cytopathologists are compelled to become familiar with the range of cytologic features of DSRCT. In addition, postchemotherapy tumors may be sampled to confirm disease recurrence before planning additional therapy. This study was designed to compare prechemotherapy and postchemotherapy cytomorphology of DSRCT and to evaluate for distinct chemotherapy-induced changes.

METHODS

The authors searched their respective institutional databases for all DSRCT cases with an associated FNAB. FNAB slides, immunocytochemistry, and cytogenetic results were reviewed.

RESULTS

Six aspirates from 5 patients were identified, 3 of which were postchemotherapy. The postchemotherapy cases demonstrated cytologic findings not typically described in DSRCTs, including prominent and conspicuous nucleoli, discohesive single-cell architecture, and slightly larger cell size.

CONCLUSIONS

Cytomorphologic variability was prominent in prechemotherapy cases, and no case could be classified as DSRCT on cytology alone; immunohistochemistry was necessary for definitive diagnosis. Chemotherapy increased the spectrum of cytologic features. The most notable difference between the 2 groups was a predominantly discohesive single-cell pattern with conspicuous nucleoli in the postchemotherapy group, instead of the clustering pattern of medium-sized cells with inconspicuous nucleoli typically attributed to de novo cases reported in the literature.

Desmoplastic small round cell tumor: Using FISH as an ancillary technique to support cytologic diagnosis in an unusual case

Desmoplastic small round cell tumor is a rare and aggressive neoplasm that predominantly affects young males. In almost all cases, a reciprocal translocation is present resulting in the fusion of the Ewing sarcoma gene with the Wilms' tumor gene. Here we describe an unusual case occurring in a 59-year-old male, in which fluorescence in situ hybridization (FISH) was used in conjunction with immunohistochemical studies to confirm the diagnosis. To our knowledge, this is the first reported case of using FISH as an ancillary technique to confirm the cytologic diagnosis of this tumor.

Desmoplastic small round cell tumors: cytologic, histologic, and immunohistochemical features

Desmoplastic small round cell tumor (DSRCT) is a recently recognized clinicopathologic entity that has a predilection for adolescent males and usually affects the abdominal cavity. Due to its uncommon nature, many pathologists lack experience with this tumor. The literature regarding DSRCT is reviewed with special attention to its histologic and cytologic diagnosis. Morphologic features of DSRCT and its immunohistochemical and cytogenetic profile are summarized and differential diagnosis with other small round cell tumors is discussed. As observed by both histologic and cytologic examinations, small round blue cells and fibrosclerotic stroma are the striking morphologic features of DSRCT. The typical immunohistochemical profile is characterized by coexpression of epithelial, mesenchymal, myogenic, and neural markers. Cytogenetically, this tumor harbors a specific karyotypic abnormality, namely t(11;22)(p13;q12). These features distinguish DSRCT from other members of the family of small round cell tumors.

Desmoplastic round cell tumor of childhood: can cytology with immunocytochemistry serve as an alternative for tissue diagnosis?

There are limited reports on the cytology of desmoplastic small round cell tumors (DSRCT). Fine needle aspiration biopsy (FNAB) findings in seven aspirates from four cases of histologically and immunohistochemically confirmed cases were analyzed with the main intention of ascertaining if cytological diagnosis of DSRCT is possible. Also assessed were the immunocytochemistry(ICC) findings in these cases. The basic cytological impression was that of a cohesive small round cell tumor. Nuclei showed granular chromatin with grooves, nuclear molding and inconspicuous nucleoli. Stromal fragments were noted in all four cases. In two cases, awareness of cytological features in the appropriate clinical context led to a suggestion of the diagnosis of DSRCT on cytology itself. ICC on destained smears showed positivity for cytokeratin, epithelial membrane antigen (EMA), desmin and WT-1 in two cases. In conclusion, given the right clinical setting, a cytological diagnosis of DSRCT is plausible and in conjunction with ICC may help in documenting the polyphenotypic nature and thereby confirming the diagnosis.

Desmoplastic small round cell tumour: Cytological and immunocytochemical features

Background

Desmoplastic small round cell tumor (DSRCT) is a rare and highly aggressive neoplasm. The cytological diagnosis of these tumors can be difficult because they show morphological features quite similar to other small round blue cells tumors. We described four cases of DSRCT with cytological sampling: one obtained by fine needle aspiration biopsy (FNAB) and three from serous effusions. The corresponding immunocytochemical panel was also reviewed.

Methods

Papanicolaou stained samples from FNAB and effusions were morphologically described. Immunoreaction with WT1 antibody was performed in all cytological samples. An immunohistochemical panel including the following antibodies was performed in the corresponding biopsies: 34BE12, AE1/AE3, Chromogranin A, CK20, CK7, CK8, Desmin, EMA, NSE, Vimentin and WT1.

Results

The smears showed high cellularity with minor size alteration. Nuclei were round to oval, some of them with inconspicuous nucleoli. Tumor cells are clustered, showing rosette-like feature. Tumor cells in effusions and FNA were positive to WT1 in 3 of 4 cytology specimens (2 out 3 effusions and one FNA). Immunohistochemical reactions for vimentin, NSE, AE1/AE3 and WT1 were positive in all cases in tissue sections.

Conclusion

The use of an adjunct immunocytochemical panel coupled with the cytomorphological characteristics allows the diagnosis of DSRCT in cytological specimens.