Malignant Small Round Cell Tumor Research Articles

Primitive neuroectodermal tumour of the chest wall

The concept of primitive neuroectodermal tumour (PNET) has been evolving for many years, as has its nomenclature. It was first described as a tumour arising in peripheral nerve, when it was called neuroepithelioma. These tumours are part of the differential diagnosis of malignant small round cell tumours, which include Ewing's sarcoma, rhabdomyosarcoma, neuroblastoma and lymphoma, and which appear as sheets of monotonous small round cells on light microscopy, staining dark blue with haematoxylin and eosin. In the 1970's, reports of tumours displaying neural features introduced new terms such as primitive neuroectodermal tumour and peripheral neuroectodermal tumour. A relationship to the undifferentiated primitive neuroectodermal tumours of the central nervous system in children was assumed by the title of these tumours, although it was recognised that they were not necessarily related to peripheral nerves.

Extraskeletal Ewing's sarcoma of the parotid region: a case report with the detection of the tumour's immunophenotypical characteristics

A case report of a malignant small round cell tumour of the parotid region, with features of extraskeletal Ewing's sarcoma is presented. Besides its rare location in the soft tissues of the parotid area, the tumour expressed focal NSE and desmin immunoreactivity, indicative of multidirectional differentiation.

Malignant small round cell tumor (Ewing's-PNET) of the chest wall in children

From 1976 to 1989 the authors treated 21 infants and children with malignant tumors of the chest wall. Fifteen were classified as Askin's tumors or Ewing's sarcoma, which we now consider as a single entity of primitive neuroectodermal origin. They are infrequent but highly aggressive tumors that involve the chest wall in children. Five patients presented with metastatic disease; despite chemotherapy and radiotherapy, all succumbed to progressive disease. Ten patients with localized disease received combined modality therapy including surgical resection (three after initial chemotherapy), radiotherapy, and chemotherapy. Surgery involved resection of the mass and up to three ribs, with prosthetic mesh reconstruction in one patient. Six of the 10 patients with localized disease are continuously disease-free 3.5 to 9 years (median, 5 years) following diagnosis. No patient had local recurrence. Of the four whose treatment failed, one died (free of disease) from complications after resection of an extensive primary tumor. In the second patient, acute monocytic leukemia developed shortly after relapse in a distant bone site. The patient died during induction for the leukemia. In the other two patients, hilar and carinal lymph node relapse occurred 68 and 80 months after initial treatment. One of the patients is considered in second remission (now 105 months later) after further chemotherapy (Adria-VAC) and radiation; the other succumbed to secondary relapse 17 months after second remission was achieved through chemotherapy, radiation, and surgery. Initial percutaneous needle biopsy of the large lesions has provided adequate material for histological, immunohistochemical, cytogenetic, and ultrastructural diagnosis, and permitted initial chemotherapy before proceeding to surgical resection. Preliminary chemotherapy was very advantageous in shrinking the tumor and markedly decreasing its vascularity. In fact, no viable tumor was identified in the specimens resected after initial chemotherapy in three of five children (two with metastases). Resection of the primary tumor before radiotherapy allows accurate marking of the area of involvement to permit limited radiation of the thorax. With this intensive multimodality therapy, the authors have achieved a predicted life-table survival of 53% in patients without metastatic disease at presentation, and there has been no local chest wall recurrence.

Role of intraoperative cytopathology in pediatric surgical pathology

Studies regarding the efficacy of intraoperative cytopathology (IOC) of surgical specimens in the pediatric population are almost non-existent, despite their recent popularity in adults. To determine the utility of IOC in children, we examined 58 cases from 54 pediatric patients (neonate to 18 years of age) who had cytologic smears performed in addition to or instead of forzen section (FS) examination during their surgical procedure. Knowing only the patient's age, sex, anatomic site, and any pertinent radiographic or historic data, three pathologists independently reviewed and issued a diagnosis using only the IOC smears. Subsequently, in 28 cases that also had accompanying FS examination, both IOC and FS analysis were interpreted for a composite final diagnosis. Three cases were judged unsatisfactory because of sparse cellularity of smears. Correct classification of the smears as being benign or malignant for each pathologist was 98%, 94%, and 94% using IOC alone and 98%, 94%, and 96% using combined IOC and FS examination. The most frequent anatomic sites were bone (15 cases) and lymph node (14 cases). The most common diagnoses were malignant small round cell tumor (22 cases) and benign lymphoid tissue (10 cases). The records of all 55 cases were reviewed in the second phase of our study. Twenty-seven cases (49%) were found in which IOC diagnoses were rendered without a concurrent FS examination. These were correctly interpreted in 26 of 27 cases (96%) in the determination of a benign versus malignant disease process. The tissue sample measured ⩽2 cm in 15 of 27 cases (56%) in this latter group. Intraoperative cytopathology diagnoses in this group were rendered by various faculty members on call for FS examination and, in some cases, by fifth-year residents with faculty supervision. Without minimizing the degree of difficulty in the interpretation of pediatric IOC, we conclude that it serves as a useful supplement in FS diagnosis and, in some situations (particularly when tissue is limited), can replace histologic FS examination.

Does malignant small round cell tumor of the thoracopulmonary region (Askin tumor) constitute a clinicopathologic entity? An analysis of 30 cases with immunohistochemical and electron-microscopic support treated at the Institute Gustave Roussy : Contesso G, Llombart-Bosch A, Terrier P, Peydro-Olaya A, Henry-Amar M, Oberlin O et al. Departmento de Patologia, Facultad de Medicina, Avenida Blasco Ibanez 17, 46010 Valencia. Cancer

Does malignant small round cell tumor of the thoracopulmonary region (Askin tumor) constitute a clinicopathologic entity? An analysis of 30 cases with immunohistochemical and electron-microscopic support treated at the Institute Gustave Roussy : Contesso G, Llombart-Bosch A, Terrier P, Peydro-Olaya A, Henry-Amar M, Oberlin O et al. Departmento de Patologia, Facultad de Medicina, Avenida Blasco Ibanez 17, 46010 Valencia. Cancer

Primary malignant small round cell tumor of the abdomen: CT findings in five cases.

Malignant small round cell tumor of the abdomen is a newly described clinicopathologic entity. The features of this entity include a predilection for young men, predominant abdominopelvic location, and aggressive behavior. Pathologic analysis demonstrates a small-cell tumor unusually coexpressing desmin and keratin. This study describes CT characteristics in five patients with malignant small round cell tumor of the abdomen. All patients were young white men, 20-36 years old (mean, 28 years). In all five cases, CT scans revealed lobulated masses appearing to arise primarily from peritoneal surfaces and predominantly involving the peritoneal cavity of the abdomen (two cases) and pelvis (two cases); diffuse abdominopelvic involvement was noted in one case. The masses were centrally necrotic and enhanced inhomogeneously after administration of iodinated contrast material. Additional CT features included ascites (one case), calcifications in the dominant mass (one case), omental implants (two cases), hydronephrosis (four cases), anterior diaphragmatic lymphadenopathy (two cases), liver metastases (two cases), and retroperitoneal lymphadenopathy (two cases). CT findings of abdominal malignant small round cell tumor are nonspecific and mimic findings noted in other conditions, such as peritoneal carcinomatosis and leiomyosarcomatosis.

Chest wall tumors in infancy and childhood.

The chest wall is an infrequent site of malignancy in infancy and childhood. Management of these tumors, however, is of particular concern because of their aggressive behavior and the functional impairment which may result from local treatment. From 1976 to 1987 we have treated seventeen infants and children with tumors of the chest wall. Askin's tumors and Ewing's sarcoma were considered as a single entity, malignant small round cell tumor (MSRCT), and account for the majority (11 of the 17 patients). Other tumors represented were infantile fibrosarcoma (1), undifferentiated spindle cell sarcomas (2), osteogenic sarcoma (1), large cell lymphoma (1), and synovial sarcoma (1). Nine of 17 patients have survived (median follow-up of survivors 5 years); six patients died of disease and two from complications of therapy. All four patients with MSRCT and metastasis at diagnosis died of disease despite chemotherapy and radiotherapy. Four of the seven patients with localized MSRCT, who received combined modality therapy including resection (two after initial chemotherapy), radiotherapy, and chemotherapy, were continuously disease-free 16 months to 10 years following diagnosis. One of the three patients who failed died of complications of surgery to her extensive primary. A second patient had a relapse of disease in a hilar node four years after finishing vincristine, actinomycin, and cytoxan (VAC) chemotherapy; she was retreated with Adriamycin (doxorubicin, Adria Laboratories, Columbus, Ohio), vincristine, and cyclophosphamide as well as radiotherapy to her hilum and remains in second remission 56 months following her recurrence. The third patient suffered a distant relapse in bone and, before succumbing to his MSRCT, developed acute monocytic leukemia and died during a remission induction attempt. Mixed results were obtained for the patients with other tumor types.

Melanotic Neuroectodermal Tumor of Infancy Occurring in the Left Thigh of a 6-Month-Old Female Infant

We report an exceptional case of melanotic neuroectodermal tumor of infancy (MNTI) occurring in the soft tissue of the left thigh of a 6-month-old female infant. The tumor consisted mainly of small round cells (neuroblasts) arranged in cords and nests that were separated by broad fibrovascular areas. In addition, there were a few medium-sized tumor cells containing melanin pigment (melanocytic cells) that in electron microscopy contained melanosomes as well as tonofilaments. Both tumor cell types immunostained for neuron-specific enolase (NSE) and vimentin, and the melanocytic cells reacted additionally with the antikeratin antibody KL1. Within the tumor stroma, neurofilament- and S-100-protein-positive neural cells and vimentin- and desmin-positive myofibroblasts were seen. Although dense-core granules were demonstrated ultrastructurally in some neuroblasts, no immunostaining for chromogranin A, Leu-7, serotonin, or regulatory peptides was found. MNTI located in an extremity can be confused with malignant small round and blue cell tumors of childhood. The distinction between MNTI and these tumors is of clinical significance because MNTI, in most cases, is a benign tumor that, in contrast to the latter, can be cured by complete excision. The presence of a biphasic cell population with neuroblasts and melanocytic cells must be considered the main diagnostic feature of MNTI.

Malignant Small Round Cell Tumor of the Thoracopulmonary Region in Childhood

Malignant Small Round Cell Tumor of the Thoracopulmonary Region in Childhood

Role of immunohistochemistry in the diagnosis of malignant small round cell tumors

Background: Immunohistochemistry is a key tool for the analysis of localization of target molecules within tissues. It has a significant role in the identification of tumors lacking evidence of lineage differentiation on the basis of routine light microscopic morphology alone. Approximately 90% of tumors posing diagnostic difficulties by morphology could be accurately classified by exploiting immunohistochemistry. The aim of this study is to identify the true identity of malignant small round cell tumors by immunohistochemical analysis. Materials and Methods:This was a retrospective study done in Department of Histopathology of B.P.Koirala Memorial Cancer Hospital from January 2010 to April 2011.A total of 40 cases small round cell tumors were selected for immunostaining. The immunohistochemistry technique used is the Polymer detection-EnvisionTM System, a two step staining technique based on Horse Radish Peroxidase labeled dextran polymer technology (DAKO Company). Results: Out of 40 cases of malignant small round cell tumors, there were 21 cases (52.5%) of Non- Hodgkin Lymphoma , 11 cases (27.5%) of Ewing’s Sarcoma/Primitive Neuroectodermal Tumor, 1 case (2.5%) of Lymphoblastic Lymphoma , 1 case (2.5%) of Rhabdomyosarcoma, 2 cases (5%) of Low grade neuroendocrine tumor, 1 case (2.5%) of Neuroblastoma, 2 cases (5%) of Poorly differentiated Synovial Sarcoma (small cell variant), 1case (2.5%) of Malignant Melanoma (small cell variant). Conclusion: Immunohistochemistry is a valuable adjunct to routine hematoxylin and eosin staining for adequate and accurate categorization of malignant small round cell tumors. Keywords: Immunohistochemistry; Malignant Small Round Cell Tumor; Non Hodgkin’s Lymphoma; Ewing’s Sarcoma; Rhabdomyosarcoma DOI: http://dx.doi.org/10.3126/jpn.v1i2.5398 JPN 2011; 1(2): 87-91