促纤维化小圆细胞肿瘤5例临床病理、免疫组化及电镜观察

目的：观察５例促纤维化小圆细胞肿瘤的临床病理特点,提高对此类肿瘤的认识。方法：常规组织学（ＨＥ）、免疫组化（ＡＢＣ法）和电镜技术检测结合临床资料综合分析。结果：５例中２例多次局部复发,２例在随访中,１例确诊后４个月死亡。该肿瘤组织学特点为肿瘤组织呈单结节或多结节状浸润生长,伴有明显致密的成熟纤维性间质增性,肿瘤细胞主要为大小比较一致的小圆形细胞,呈团状或巢状埋于增生纤维间质中,少数病例部分区域肿瘤     

Desmoplastic small round cell tumor presenting as a neck mass: a case report

An unusual case study of a desmoplastic small round cell tumor presenting as a 3.5-cm, firm, supraclavicular neck mass and diagnosed by fine-needle aspirate biopsy in a 16-yr-old male is reported. Clinical, cytologic, and immunocytochemical findings are described. Histologic, immunohistochemical, and genetic features are discussed. Desmoplastic small round cell tumor should be considered in the differential diagnosis of small round cell tumors of any site; the importance of ancillary studies in arriving at the correct diagnosis is emphasized.     

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.     

促纤维组织增生性小圆细胞肿瘤2例报道及文献复习

目的 探讨促纤维组织增生性小圆细胞肿瘤的临床病理特点,提高诊断水平.方法 对2例本病少见部位发生者临床病理资料进行分析,并行组织病理学(HE)和免疫组化(SP法)观察.结果 该肿瘤多呈单结节或多结节状浸润性生长,瘤细胞小圆形、核深染、胞质少,呈团、巢状排列,间质有大量增生的纤维结缔组织.免疫表型同时表达上皮性、间叶性和神经源性标记物.结论 促纤维组织增生性小圆细胞肿瘤罕见,临床表现复杂,可发生在腹腔也可在其他部位.肿瘤具有特征性的组织学和免疫组化表现.预后大多较差.     

Unusual aspects of desmoplastic small round cell tumor

Desmoplastic small round cell tumor (DSRCT) is a neoplasia that occurs mainly in childhood and involves abdominal or peritoneal sites, coexpressing ectodermal and mesenchimal immunophenotypic markers, and is endowed with an impressive stromal desmoplasia that tends to decrease on tumor relapse. To date, over 150 cases have been collected in the literature. Its presumed neuroectodermal histogenesis has been challenged by cytogenetic findings different from those usually associated with neoplasms of neuroectodermal origin. The authors report a case bearing clinical and histologic aspects of typical desmoplastic retroperitoneal small cell tumor, with intense and diffuse nuclear immunopositivity for WT1, but lacking divergent immunophenotype. Ultrastructural investigation revealed that desmoplasia could result from fibrillary synthesis by neoplastic cells.     

Pathologic, cytologic and immunohistochemical findings of an intra-abdominal desmoplastic small round cell tumor in a 15-year-old male

The intra-abdominal desmoplastic small round cell tumor is a rare neoplasm. It usually occurs in young males and diffusely involves the peritoneum and pursues an aggressive clinical course. The present patient was a 15-year-old male who experienced abdominal pain and abdominal swelling. The patient was diagnosed with an intestinal myogenic sarcoma, and surgery for tumor resection was performed in June 1999. The tumor was a 20 x 15 x 15 cm well-defined mass in the peritoneum involving the transverse colon and stomach with peritoneal disseminations and splenic metastasis. Microscopic findings were well-defined nests composed of small round cells and separated by abundant desmoplastic stroma. Cytologically, the tumor cells consisted of small, round to oval cells with a scant amount of light blue cytoplasm. Immunohistochemically, the tumor cells were positive for anti-epithelial membrane antigen, vimentin, desmin, neuron-specific enolase and WT1 protein antibodies. Similar pathologic features with other small round cell tumors may lead to differential diagnostic difficulties that require the application of ancillary diagnostic methods, such as immunohistochemistry and cytogenetic techniques.     

Two autopsy cases of desmoplastic small round cell tumor

Desmoplastic small round cell tumor (DSRCT) is a rare aggressive malignant tumor. It is a refractory tumor and the median overall survival is very short. We report two autopsy cases of DSRCT, both of which were already advanced and metastasized at the first medical examination. Both cases showed typical DSRCT findings in terms of localization of the lesions, histopathology and genetics, but the rate of disease progression was quite different. Survival after initial symptoms in Case 1 was only 12 months. On the other hand, survival after primary hospitalization in Case 2 was 42 months. The Case 2 patient initially received chemotherapy for advanced pancreatic carcinoma, because a nodule of the pancreatic tail was found on computed tomography (CT) scan. After chemotherapy, tumor regression was observed on CT scan. It is thus implied that adoption of the regimen for pancreatic carcinoma might have been one of reasons of the long survival in Case 2.     

Intraabdominal desmoplastic small round cell tumor: Cytopathologic findings in two cases

Intraabdominal desmoplastic small round cell tumor (DSRCT) is an extremely rare entity. This study describes fine-needle aspiration, ascitic fluid, and touch imprint cytomorphology of DSRCT in 2 patients with extensive abdomino-pelvic disease. Cytopathologic features were unique and showed good morphologic correlation with subsequent histology of the resected tumor. Immunocytochemical profile and differential diagnosis with other small round cell tumors in this age group are also discussed. Diagn. Cytopathol. 1998;18:449–452. © 1998 Wiley-Liss, Inc.     

Immunohistochemical detection of the Wilms' tumour gene WT1 in desmoplastic small round cell tumour

The desmoplastic small round cell tumour (DSRCT) is a rare, highly malignant neoplasm usually presenting in the abdomen of adolescent males. A characteristic translocation between the Ewing's sarcoma gene on chromosome 22 and the Wilms' tumour gene WT1 on chromosome 11 has been described, producing a fusion gene with expression of the DNA binding area of WT1. Some Wilms' tumour antibodies recognize epitopes of this part of the WT1 protein. All four cases of DSRCT examined showed strong staining of the tumours with an anti-WT1 antibody, suggesting this may be useful in the diagnosis of these tumours.     

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.     

Peritoneal Desmoplastic Small Round Cell Tumors with Divergent Differentiation: A Review

Peritoneal desmoplastic small round cell tumors with divergent differentiation are recently described highly aggressive neoplasms with characteristic clinical, morphologic, and immunohistochemical features. This review covers 38 cases that have been reported in the literature. The average age of patients is 18.4 years, and males are affected twice as frequently as females. Tumors generally present as multiple peritoneal nodules without obvious organ involvement. Histology shows islands of small cells set in dense desmoplastic stroma. Immunohistochemical stains are usually positive for cytokeratins, epithelial membrane antigen, desmin, and vimentin. Many cases also stain for neuron-specific enolase but rarely for other neuroepithelial markers. Ultrastructural appearances range from undifferentiated small cells to larger epithelial elements. Paranuclear aggregates of intermediate filaments are characteristic. Dense-core granules and other neuroendocrine features have been described in a minority of cases. Some tumors respond to chemotherapy, but most patients die within months to a few years. The histogenesis of these tumors is uncertain.     

Postmenopausal intra-abdominal desmoplastic small cell tumor

Intra-abdomlnal desmoplastic small cell tumor (DSCT) usually occurs In infants and young male adults. A case of DSCT occurring in a 60 year old female Is described. No other apparent primary origin was detected. A mesocolon tumor, measuring 23times12times10cm, was composed predominantly of round to spindle cells which showed epithelioid- and focally sarcomatous arrangements. Irnmunohlstochemically, the tumor cells showed perinuclear dot-like staining of CAM5.2, many cells expressed HHF35, and some cells contained vimentin, epithelial membrane antigen, desmln, alpha-smooth muscle actin, neuron-specific enolase, or Leu 7. Electron microscopic examination showed that the tumor cells had mesenchymal-fibroblastic features. The tumor had an aneuploid DNA content with high S-phase fraction. The patient, who was treated with adjuvant chemotherapy, was alive, having had three recurrences in 36 months. In the second and third recurrent lesions, increased cellular atypla and fascicular arrangements of spindle cells were observed. DSCT should be included in differential diagnoses of postmenopausal pelvic tumors which show light-microscopically and immunohistochemically divergent phenotypes.     

Abdominal small round cell tumor with osteoid and EWS/FLI1

In this report, we described a case of multiple intraperitoneal tumors. Histologically, the tumors were composed of small round cells with malignant phenotype, necrotic areas, and islands of osteoid matrix in the stroma. In immunohistochemical and molecular analyses, the tumors expressed CD99 and EWS-Fli1 fusion gene. Production of osteoid by small round tumor cells was consistent with the histologic criteria of small-cell osteosarcoma, whereas expression of EWS-Fli1 was a characteristic genetic feature of Ewing's sarcoma family of tumor. Such tumors have been limited to a case in which histologically proven small-cell osteosarcoma of the scapula showed a chromosomal translocation, t(11;22)(q24;q12).     

Acute megakaryoblastic leukemia mimicking small round cell tumor with novel t(1;5)(q21;p13)

Acute megakaryoblastic leukemia is a relatively rare form of acute leukemia that has heterogeneous blast morphology and karyotypic abnormalities. An 8-month-old boy with a retroperitoneal mass was diagnosed as having acute megakaryoblastic leukemia that initially presented as small round cell tumor of childhood. Bone marrow aspiration showed syncytial groups of atypical medium sized cells with scant cytoplasm and fine nuclear chromatin. Retroperitoneal mass biopsy showed several lymph nodes with cohesive clusters of neoplastic cells that demonstrated expression of Factor VIII. Flow cytometric analysis of the second bone marrow aspiration showed CD 61 positivity. Karyotypic analysis of bone marrow cells showed a novel translocation, (1;5)(q21;p13).     

Biphasic intraabdominal desmoplastic small round cell tumor: Fine-needle aspiration cytology findings

The present report describes the case of a 9-yr-old boy with an abdominal desmoplastic small round cell tumor (DSRCT) which on fine-needle aspiration cytology and histology revealed a biphasic pattern, making initial diagnosis difficult. Epithelial-like clusters of cells and loosely-arranged poorly-differentiated cells with scant cytoplasm associated with cells having a larger nucleus and multinucleated larger cells represented the smears' counterpart of epithelial clusters and lobules and sarcomatous-like tissue recognized in the histologic sections. Multinucleated cells were common in the sarcomatous-like areas of the tumor. The biphasic pattern was highlighted by immunohistochemistry. Keratin and epithelial membrane antigen stained predominantly or only the epithelial component, while desmin diffusely decorated the sarcomatous areas and the epithelial cells as a paranuclear cytoplasmic dot. Immunosera 013 mainly stained the sarcomatous component. © 1995 Wiley-Liss, Inc.     

Desmoplastic small round cell tumor of the central nervous system: report of two cases and review of the literature

Desmoplastic small round cell tumor (DSRCT) is a malignant tumor often involving the abdominal and/or pelvic peritoneum. Only one fully documented example has arisen in the central nervous system (CNS). Herein, we describe two additional examples, fulfilling the morphologic, immunohistochemical, and molecular criteria (EWS/WT1 translocation) of DSRCT. Both arose in the cerebellopontine angle (CPA) and underwent spinal dissemination. Patient 1, a 37-year-old male, underwent a subtotal resection, and 2 years later died of recurrent disease with spinal dissemination. Patient 2, a 39-year-old man, presented with cerebellar and CPA lesions as well as spinal leptomeningeal deposits. After 27 months of adjuvant therapy, he is alive with progressive disease. In conclusion, CNS DSRCT follows a similar aggressive course as do peritoneal examples. Although rare, DSRCT warrants consideration in the differential diagnosis of “malignant small blue cell tumors” of the CNS. For consideration of publication in Virchows Archiv.     

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.