Canine intrathoracic sarcoma with ultrastructural characteristics of human synovial sarcoma - case report.

BACKGROUND: Canine joint sarcomas, designated synovial sarcomas, are uncommon malignant mesenchymal neoplasms that occur in the large joints of the extremities of middle-aged, large-breed dogs. We report the diagnosis of an intrathoracic sarcoma with ultrastructural characteristics reminiscent of human synovial sarcoma in a dog. CASE PRESENTATION: A 7-year-old female spayed Tibetan terrier crossbred dog was presented for acute severe labored breathing and diagnosed with an intrathoracic neoplastic mass. The neoplasm resulted in the accumulation of substantial amounts of viscous pleural fluid that led to dyspnea. The neoplastic mass consisted of interweaving bundles of large pleomorphic mesenchymal cells, supported by an alcian blue positive myxomatous matrix. The neoplastic cells were immunohistochemically negative for cytokeratin and CD18. Transmission electron microscopy indicated that the neoplastic cells had desmosome junctions, short microvilli-like structures and ample amounts of rough endoplasmic reticulum resembling type B-like synoviocytes and synovial sarcoma as reported in people. Despite complete surgical excision of the neoplastic mass, clinical signs recurred after a month and led to the euthanasia of the dog. CONCLUSION: Currently, there are no immunohistochemical markers specific for synovial sarcoma. Canine neoplasms with transmission electron microscopy characteristics resembling type B-like synoviocytes should be considered similar to the human sarcomas that carry the specific translocations between chromosomes X and 18.

Intrathoracic rhabdoid carcinoma: a clinicopathological, immunohistochemical, and ultrastructural study of 6 cases.

We evaluated the clinicopathological spectrum of intrathoracic rhabdoid carcinoma, including its immunophenotype and ultrastructural features. Our series included 6 cases arising from the lung (4 cases) and the anterior mediastinum (2 cases). The patients were 4 men and 1 woman aged between 40 and 63 years (median, 53 years). Microscopically, all of the lesions were composed of loosely cohesive, large, atypical polygonal cells, with glassy cytoplasms and eccentric nuclei. Chromatin texture was finely granular or open. On immunohistochemical stain, the neoplastic cells were positive for vimentin in all cases, positive for vimentin, keratins and/or epithelial membrane antigen in all cases, and negative for other antigens. In 1 case, neoplastic cells were also positive for CD34. Electron microscopic study showed prominent perinuclear whorls of densely packed intermediate filaments or mitochondria. All patients were treated with combined chemotherapy and radiotherapy. One patient died 8 months after the diagnosis was made. Of the remaining patients, 3 are alive with evidence of disease progression, including brain metastases. We concluded that rhabdoid neoplasms arising in the thoracic cavity are aggressive tumors of epithelial lineage and should be categorized as true "rhabdoid carcinomas" instead of being ambiguously designated as "intrathoracic rhabdoid tumors" or "carcinomas with rhabdoid phenotype."

Rhabdomyosarcoma in a ferret (Mustela putorius furo).

A 5-year-old spayed male ferret showed a subcutaneous mass in the right lateral thoracic wall. Microscopic examination revealed that the neoplasm had proliferated in the subcutis with infiltration into the surrounding tissues. A packed bundle of large polymorphic neoplastic cells, containing abundant eosinophilic cytoplasm and a round to ovoid, occasionally bizarre nucleus, were arranged interwoven. The neoplasm had metastasized to the right axillary lymph node. The neoplastic cells were intensively positive for vimentin, desmin and myoglobin. Skeletal muscle type creatine phosphokinase-positive granules were detected in the cytoplasm. Ultrastructurally, various amounts of disorganized myofibrils with focal density resembling the Z-band were shown in the cytoplasm of the neoplastic cells. The neoplasia was diagnosed as rhabdomyosarcoma.

Subcutaneous panniculitis-like T-cell lymphoma: further evidence for a distinct neoplasm originating from large granular lymphocytes of T/NK phenotype.

We report the case of a 20 year-old caucasian woman who presented a primary subcutaneous panniculitis-like T-cell lymphoma (SPTCL) as an invasive tumor of the chest wall. Herein, the neoplastic cells were found to express a CD3+CD8+ phenotype but also displayed variably the natural killer (NK)-associated antigens CD56 and CD57 as well as granzyme B. On cytological examination, these cells showed a large granular lymphocyte (LGL)-like morphology with presence of azurophilic granules in their cytoplasm. Electron dense and membrane bound granules like those found in cytotoxic T lymphocytes (CTL) were also demonstrated by electron microscopy. Neither rearrangement of the T-cell receptor subunits nor Epstein-Barr virus (EBV) genome was observed at the molecular level. The LGL-like features of the neoplastic cells found in this case and the presence of NK-associated antigens provide additional support to the cytotoxic derivation of most SPTCL.

Solitary fibrous tumor of the spinal cord.

We report a case of primary solitary fibrous tumor occurring in the intramedullary thoracic spinal cord in a 47-year-old man. The tumor predominately consisted of spindle cells separated by abundant collagen; a few areas of hemangiopericytomatous morphology were also present. The diagnosis was confirmed by immunohistochemistry and electron microscopy. The tumor was reactive to vimentin and CD34 but was negative for glial fibrillary acid protein (GFAP), S-100, smooth muscle actin, epithelial membrane antigen, HMB-45, myelin basic protein, and keratin; ultrastructural examination showed fairly undifferentiated cells within a collagenous matrix, few tight junctions, and sparse extravascular basement membrane. The occurrence of this tumor within the spinal cord parenchyma and in other extraserosal sites emphasizes the current belief that solitary fibrous tumors arise from mesenchymal tissues and are not restricted to the pleura and other serosal surfaces. Furthermore, solitary fibrous tumor is an entity that must be considered in the differential diagnosis of spindle cell central nervous system neoplasms.

Leucocyte and endothelial cell adhesion molecule expression in porcine histiocytic leiomyofibrosarcoma.

A histiocytic sarcoma was present at birth in a pig. On the basis of ultra-structure and structural-protein composition (presence of alpha-smooth-muscle actin but not keratin), the sarcoma component was identified as a leiomyofibrosarcoma. Lipid-laden macrophages (histiocytes), which permeated the tumour in an apparently random fashion, were somewhat atypical in that they were negative for some macrophage markers; they gave a reaction, however, for CDw14. Despite its aggressive metastatic capacity, this tumour occurred almost exclusively in the subcutis, dermis and skeletal muscle. The tumour was extensively vascularized with many small capillaries which did not express E-selectin (CD69E), MHC class II or the L-selectin (CD69L) ligand, markers characteristic of inflamed (activated) endothelial cells in pig skin. Significant numbers of the histiocytes were positive for the integrins CD18 and VLA-4 (CD49d), indicating involvement of integrin pathways in the spread or growth, or both, of the leiomyofibrosarcoma. Most of the fibrous sarcoma cells also had extensive reactivity with an antibody to the standard variant form of CD44 (CD44s).

Carcinoma arising in ectopic hamartomatous thymoma. An ultrastructural study.

We present the ultrastructural features of a case of adenocarcinoma arising in ectopic hamartomatous thymoma in a 31 year old man, in the supraclavicular location. The tumor had a cribriform adenomatous component with a granular cell quality and mimicked a metastatic carcinoma. Ultrastructurally, the spindle cell component revealed clusters of tonofilaments and the tumor cells were attached by well developed desmosomes. The cytoplasm of adenocarcinoma cells contained peculiar cup-shaped bodies derived from the endoplasmic reticulum wrapped around the mitochondria.

Small round and spindle cell sarcoma with neuronal differentiation and oncocyte-like features of the thoracic wall: a case report with histological, immunohistochemical and ultrastructural examinations.

A case of small round and spindle cell sarcoma with neuronal differentiation and oncocyte-like features is presented. The tumor was encountered in a 32 year old Japanese woman with an initial presentation of palpable tumor in the left lateral region of the thorax. The resected tumor was a partially well encapsulated whitish medullary one and consisted of small round and spindle tumor cells, together with so-called rhabdoid cells in the small round cell area. Although pseudorosettes were often observed, true rosette formation could not be detected anywhere. Ultrastructurally, despite a histologic variety of tumor cells, most tumor cells possessed numerous mitochondria, some of which occasionally contained abnormal filamentous or crystalloid structures. Various amounts of microfilaments were present in most tumor cells and microtubules were present in a few. A minority of small round cells possessed a small number of neurosecretory granules, especially in short cytoplasmic processes. A positive immunoreaction for neuron specific enolase was found by immunohistochemical examination in several small round tumor cells and for neurofilaments in lesser numbers. Despite the lack of S-100 protein, MB2 was detected in both small round and spindle cells. On the basis of these findings, the tumor of the present case corresponds to malignant peripheral nerve sheath tumor with neuronal differentiation and oncocytic features.

[Ultrastructural analysis of liposarcoma].

9 cases of liposarcoma, including 5 myxoid type, 3 pleomorphic type and 1 well differentiated type, were studied with light, electron microscopy and immunohistochemistry. Comparative observations revealed similarities between liposarcoma cells and cells of developing fat tissue. Liposarcoma cells resemble primary mesenchymal cells, fibroblasts, early, midstage and late lipoblasts or mature lipocytes. But certain differences also exist: First, atypia in liposarcoma cells, such as the appearance of mono- or multinuclei giant lipoblasts in some cases. Second, certain types of liposarcoma are predominated by lipoblasts of a specific stage. Under electron microscope, transitional morphology from both primary mesenchymal cell and fibroblast to lipoblast can be observed, which is an indication that lipoblasts may originate from these two types of cells. Differential diagnosis by electron microscopy is also discussed.

Association between ATL and non-hematopoietic neoplasms.

A high incidence of multiple primary neoplasms has been observed in our patients with ATL in comparison to persons with other forms of hematologic malignancy who we have observed during the past 23 years (1963-1985). Five of 15 patients with ATL (33.3 per cent) have had at least one other associated neoplasm in comparison to only 44 of 1156 patients with other forms of hematological malignancy (3.8 per cent). The incidence figures for secondary neoplasms associated with the other hematologic malignancies were 4.3 per cent (16/370) for acute non-lymphocytic leukemia (ANLL), 2.2 per cent (2/90) for acute lymphocytic leukemia (ALL), 4.8 per cent (1/21) for acute unclassifiable leukemia, 2.2 per cent (5/225) for chronic myelogenous leukemia, 4.7 per cent (2/43) for chronic lymphocytic leukemia, 5.9 per cent (8/136) for malignant monoclonal gammopathy and 3.7 per cent (10/271) for malignant lymphoma. The incidence of multiple neoplasms in patients with ATL in comparison to those with other hematological malignancies was statistically significant (p < 0.01 or p < 0.001). The neoplasms associated with ATL have been adenocarcinoma of the thyroid or stomach, and squamous cell carcinoma of the larynx, lip or lung. We identified ATL-derived factor (ADF) in the cytoplasm of the secondary neoplasms of the ATL patients by means of indirect immunofluoroscopy and immunohistochemical techniques utilizing anti-ADF antibody. We also identified ras p21 products in these neoplasms by means of p21 ras monoclonal antibody studies. The possibility that HTLV-I was the cause of the secondary neoplasms thus was investigated. HTLV-I provirus genome was not found in all the six cases of non-ATL leukemic cells of the patients with anti-HTLV-I antibodies as determined by means of Southern blot analysis utilizing pX DNA probe. These findings suggest that there is some association between ATL cells and pre-malignant cells through ADF or other unknown factors in the activation of ras oncogenes. Subsequent suppression of host immune defence mechanisms in ATL patients permits evolution of the secondary neoplasms.

Cytogenetics of Askin's tumour. Case report and review of the literature.

The eleventh cytogenetically analyzed Askin's tumour, diagnosed in a two-year-old girl, is reported. Chromosomal analysis revealed a pseudodiploid karyotype of tumour cells with translocations of t(11;22)(q24;q12) and der(4)t(2;4)(q24;q35). The observed t(11;22)(q24;q12) is not only a unique characteristic of all cytogenetically analyzed Askin's tumours but it also occurs in 92-100% of peripheral neuroepithelioma and of Ewing's sarcoma, irrespective of its osseous or extraosseous localization. This genetical similarity further supports a nosological concept according to which Askin's tumour, Ewing's sarcoma and peripheral neuroepithelioma represent phenotypic variations of the same tumour, namely the peripheral primitive neuroectodermal tumour.

A case of small round cell tumor of the thoracopulmonary region with myogenic and neurogenic elements.

We here report a unique case of a young boy with an intrathoracic tumor which consisted of neurogenic and myogenic elements. The initial pathological diagnosis was alveolar rhabdomyosarcoma. The tumor tissue from surgical resection was composed of three parts, each showing a different histological appearance, i.e. a monotonous small cell area, an alveolar area, and an area consisting of pleomorphic rhabdomyoblasts. The small round cells in the monotonous area were immunoreactive with the antibodies for Leu7, neuron-specific enolase (NSE), neurofilament proteins (NFP), and beta 2 microglobulin, but not with the antibody for desmin. These cells also had dense core granules. The tumor cells in the alveolar area were immunoreactive with the antibodies for Leu7 and desmin, but not with the antibody for NFP. Pleomorphic rhabdomyoblasts were immunoreactive with the antibody for desmin, but not with the antibodies for Leu7 and NFP. These findings imply that this tumor consisted of neurogenic and myogenic elements and is considered to be a special type of rhabdomyosarcoma.

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.

The morphology and clinical outcome of 30 patients with malignant small round cell tumors located in the thoracopulmonary region (Askin tumor) are reported. Histologically, all tumors had similar patterns, with small round-to-oval cells and a lobulated stroma. Immunohistochemical analysis always resulted in positive staining for one or several neural markers. No significant differences were found compared with the immunomarkers in 26 typical Ewing's sarcomas located outside the thoracic wall. In three specimens, electron microscopy confirmed the presence of membrane-bound neurosecretory granules. It was confirmed that there is a remarkable similarity among all malignant small round cell tumors, including Askin tumor and Ewing's sarcoma. Overall survival was poor with a 2-year rate of 38% and a 6-year rate of 14%.

Rapid ultrastructural examination of FNAs in the diagnosis of intrathoracic tumors.

By coupling radiologic imaging procedures with a fine-needle aspiration (FNA) technique, superficial and deep-seated tumors of the thorax may be sampled for cytopathologic evaluation with relative ease, minimal trauma to the patient, and may avert unnecessary or contraindicated surgery. However, the cytodiagnostic limitations that apply to FNA specimens from other sites also obtain for tumors of the thoracic cavity. Although application of histo- and immunohistochemistry offers some expansion of cytodiagnostic limits, their inherent problems of technical failure and biological capriciousness demand a highly critical if not outright skeptical appraisal of the result when applied to cytology specimens. By extending the basic morphologic principles of cytodiagnosis to include fine structure, its limitations can be largely eliminated. Journals of pathology and specialized atlases contain detailed fine structural descriptions of essentially all recognized neoplasms, and the features that discriminate one neoplasm from another are now well recognized. In most instances, a few well-preserved cells or cell groups obtained from an FNA can provide a morphological diagnosis that rivals or surpasses that of conventional paraffin sections of surgically biopsied material, when evaluated in concert with the cytology preparation.

Neurilemoma de la cara interna de pared torácica / Neurilemoma of the interior face of thorax wall

Los tumores primarios de la pared del tórax son raros, pero hay que considerárseles en la evaluación de sujetos con dolor persistente en la pared torácica. Las técnicas radiográficas especiales pueden definir las posibilidades diagnósticas y la magnitud del ataque local, pero puede ser no concluyente también. En la presentación de estos casos, se desea hacer énfasis en las grandes posibilidades que hay de confundir tumores de la pared costal con tumores de parénquima pulmonar y la importancia de decidir y definir diagnóstico y tratamiento con la toracotomía exploradora

Signet-ring chondrosarcoma: a new morphologic entity.

A 65-year-old, otherwise healthy white man presenting with an asymptomatic anterior chest wall mass diagnosed from a routine preoperative chest x-ray is reported. A fine needle aspirate of the mass was initially interpreted as a metastatic adenocarcinoma with prominent "signet-ring" features, but ultrastructural study of the cell block later suggested a chondrosarcoma. The resected surgical specimen confirmed the diagnosis of a grade 2 chondrosarcoma, with most of the tumor cells containing a large, clear, single vacuole shown to be lipid. The positive immunostaining for vimentin and S-100 as well as the ultrastructural appearance confirmed the diagnosis of a chondrosarcoma. Flow cytometric DNA analysis of the tumor on two separate occasions documented a very large aneuploid cell population (50% to 60%) which, when interpreted with the histologic appearance, suggested an aggressive tumor. This case illustrates the first published example of a "signet-ring" chondrosarcoma.

Morphometry and the differential diagnosis between peripheral neuroepithelioma and neuroblastoma.

The differential diagnosis based on morphology between neuroblastoma (NB) and peripheral neuroepithelioma (PN) is difficult, since these tumors share many architectural and cytological features. In this study, a morphometrical approach to this diagnosis is made by using nuclear (shape factors) and tissue (volume density of nuclei and stroma) parameters. Quantitative morphological analysis adds important information, which when used with clinical and biochemical data facilitates the distinction. In the majority of cases, nuclei of PN are significantly less round than those of NB and their profile is much more irregular. The density of neoplastic nuclei is significantly higher in PN. However, in a certain number of cases, even the morphometrical study confirms how difficult it may be to differentiate these two neoplastic entities, since the values of parameters are largely overlapping. This suggests the existence of a "continuum" of changing features between NB and PN, which may substantiate the hypothesis of a common histogenesis.

Metachronous soft-tissue masses in children and young adults with cancer: correlation of histology and aspiration cytology.

We describe a series of 28 fine needle aspiration biopsies (FNAB) of soft tissue from 22 patients. Four patients had two separate FNABs, and one had three aspiration procedures. The patient population was limited to children and young adults (age range, 2 months to 29 years; mean, 16 years) who were known to have diverse forms of cancer, and who subsequently developed a mass in the peripheral soft tissues (including breast). The interval between the time of diagnosis of the primary malignant neoplasm and FNAB ranged from 1 day to 17 years (mean, 39 months). All FNAB diagnoses were confirmed by subsequent surgical open biopsy or clinical follow-up greater than 1 year. No complications occurred from the procedure. The cytomorphology is presented in selected cases and correlated with the patient's original tissue histopathology. Twenty aspirates were diagnosed as cytologically malignant, one as suspicious for malignancy. Seven were considered benign. None were unsatisfactory. One false-positive and no false-negative cytologic diagnoses were obtained. The overall accuracy of FNAB diagnoses was 96%, while sensitivity was 100% and specificity 88%. Sites of aspiration included soft tissues of the head and neck (seven cases), trunk (eight cases), breast (four cases), and extremities (nine cases). Malignant cytologic diagnoses included sarcoma (thirteen), seminoma (two), lymphoma/leukemia (two), melanoma (one), undifferentiated neoplasm (one), and neuroblastoma (one). Electron microscopy of aspirated cells was used to confirm the diagnosis in two cases. Fine needle aspiration biopsy of soft tissue masses from children and young adults with cancer demonstrates a high diagnostic accuracy, and its use is justified in this population.

Peripheral neuroectodermal tumour (neuroepithelioma) of the thoracopulmonary region: light and electron microscopic cytology.

We describe a case of peripheral neuroectodermal tumour of the thoracopulmonary region diagnosed by fine needle aspiration cytology. Light microscope examination revealed numerous small tumour cells arranged in large irregular aggregates occasionally delimiting empty vascular-type spaces or forming rosette-like structures. Cytologically the tumour cells showed a marked degree of nuclear anaplasia, scanty cytoplasm and long thin cytoplasmic processes. Electron microscopy revealed cells with characteristics of neuroectodermal differentiation.