Primary kaposiform hemangioendothelioma of a long bone: two cases in unusual locations with long-term follow up.

Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm of low malignant potential that mainly affects infants and adolescents. The tumor almost exclusively occurs in somatic soft tissue or the retroperitoneum. We report herein two cases of primary KHE occurring in a long bone without cutaneous changes with long-term follow up in young patients. The patients were a 9-year-old girl and 5-year-old boy presenting with lytic lesions of the femur and humerus, respectively, without cutaneous lesions. Histologically, the neoplasms were comprised of nodules of spindle- to oval-shaped cells growing in an infiltrative fashion. The neoplastic cells formed poorly canalized or slit-like blood vessels alternating with solid spindle areas. Immunohistochemical studies showed that the tumor cells expressed CD31, CD34 and Fli1, but not HHV8, LNA-1 or GLUT1. D2-40 stained the neoplastic spindle cells and lymphatic channels adjacent to vascular lobules. The girl remains well with 15 years and 6 months follow up after a second complete excision. The boy has no signs of recurrence or metastasis nearly 5 years after local complete excision. To our best knowledge, this is the first report in the English literature of primary long bone occurrences of KHE without cutaneous changes with long-term follow up.

[Adamantinoma of long tubal bones].

Four cases of adamantinomas of the long tubular bones, ulna and femur among them which rarely occur in patients aged 18-64 years (one female) are reported. A late metastasis to the sacrum was observed in one case. Typical diagnostic errors are described. Electron microscopy data are provided. Immunohistochemistry helps in differential diagnosis of this tumor. Histology does not give too much for the prognosis, radical resection does not influence the incidence of recurrences and metastases. The surgeons should be warned against enucleation of the tumor.

Histological observations on the microenvironment of osteolytic bone metastasis by breast carcinoma cell line.

Bone tissue, with its dynamic microenvironment featuring osteoclastic bone resorption, angiogenesis and matrix degradation, appears to facilitate proliferation of tumor cells after the onset of bone metastasis. In this study, we examined metastatic lesions in the femora of BALB/c nu/nu mice two weeks after intracardiac injection with human breast carcinoma MDA-231 cells. Histopathological observations showed the metastatic lesions close to the chondro-osseous junction, and revealed MDA-231 cells loosely intermingled with different cell types such as osteoblasts, fibroblastic stromal cells, osteoclasts and endothelial cells. In the metastatic nest, many tartrate resistant acid phosphatase (TRAPase)-positive osteoclasts accumulated in direct contact with or were close to alkaline phosphatase (ALPase)- or receptor activator of NF-kappaB ligand (RANKL)-positive osteoblastic cells. It seems likely that osteoclastogenesis is mediated through cell-to-cell contacts with ALPase- and RANKL-expressing osteoblastic cells. Formation of many capillaries lacking complete basal membranes and pericytes ratified the results of in situ hybridization, which revealed intense expression of VEGF in tumor nests, and therefore, indicated ongoing tumor-induced angiogenesis. The tumor cells possessed matrix metallo-proteinases (MMPs)-1 and -9, and frequently extended their stout cytoplasmic processes into fragmented fibrillar components of the growth plate cartilage, implicating degradation of cartilaginous matrix. Thus, osteolytic bone metastasis has demonstrated pathological features as tumor-induced angiogenesis and degradation of extracellular matrix, in addition to osteoclastogenesis. This complex interplay between tumor cells and host tissues may enable and nourish the establishment of a microenvironment that facilitates tumor progression.

[Primary bone leiomyosarcoma. Anatomo-clinical, immunohistochemical, and ultrastructural study]. / Le léiomyosarcome primitif de l'os. Une observation anatomo-clinique, immuno-histochimique et ultrastructurale.

A variety of tissues in bone can be the origin of neoplastic primitive lesions. Consequently, it can be the site of various sarcomas of tissue type, incursing leiomyosarcoma. The leiomyosarcoma of the bone is considered as primitive after exclusion either a bony extension of a soft tissue tumor of vicinity or the presence of a leiomyosarcoma elsewhere. We report a case of a primary leiomyosarcoma arising on the left femur of a 40-year-old woman. The diagnosis was confirmed by immuno-histochemistry and electron microscopic study. A bloc resection followed by a prothesis was performed. The patient underwent a fractioned postoperative radiotherapy with a total dose of 75 Gy. The postoperative course one year later revealed local recurrence and pulmonary metastases. Despite the resection of pulmonary metastases and the amputation of left lower limb, the patient had developed local recurrence on the stump of amputated limb and was on the outside of all therapeutic resource. In this report, we present the clinicopathologic, immuno-histochemical and ultrastructural profiles of these rare primary bone tumors.

Skeletal and extraskeletal myxoid chondrosarcoma: a comparative clinicopathologic, ultrastructural, and molecular study.

BACKGROUND: Skeletal myxoid chondrosarcoma (SMC) is considered to be either a typical chondrosarcoma with prominent myxoid alterations or an altogether unique malignant cartilage tumor. Extraskeletal myxoid chondrosarcoma (EMC) is a relatively rare but well-recognized neoplasm. It was initially thought to be a low grade sarcoma of cartilage derivation and was recently found, in most cases, to contain a reciprocal t(9;22), resulting in a fusion of the EWS and CHN genes. Are SMC and EMC the same entity arising in two different locations, or are they two separate entities? To the authors' knowledge, this study represents the first systematic attempt to answer this question. METHODS: Forty consecutive cases of EMC (20 cases) and SMC (20 cases) were compared by light and electron microscopy, immunohistochemistry, and molecular analysis. The mean clinical follow-up for both groups was 55 months. Histologic criteria for SMC consisted of 95% myxoid matrix, with only minimal hyaline cartilage formation. RESULTS: The gender distribution was identical in both groups (13 males and 7 females). The mean age was 55 years for EMC patients and 45 years for SMC patients. The EMC tumors were predominantly located in the deep soft tissues of the lower extremity (60%) and buttock (20%), and the mean tumor size was 13 cm. SMC was most commonly located in the bones around the hip joint (pelvis 35%; proximal femur 20%) and shoulder (20%); the mean size was 9 cm. Histologic grade in the EMC group correlated with survival (82% of the high grade tumors metastasized). Electron microscopy performed in 8 EMC cases revealed intracisternal microtubules in 3 cases and prominent mitochondria in 5, whereas in 5 SMC cases it revealed only inconspicuous organelles. Molecular analysis for the EWS-CHN fusion RNA resulting from the t(9;22) was performed in 15 cases (9 EMC and 6 SMC) and was detected in 7 of 9 EMC cases and 0 of 6 SMC cases. In one case, the molecular structure of the EWS-CHN fusion RNA was novel. The probability of metastasis was significantly higher (P=0.004) for the EMC group than for the SMC group. CONCLUSIONS: Although similar light microscopic features are noted in EMC and SMC, fundamental differences are noted at the ultrastructural and molecular levels, suggesting that EMC and SMC represent two distinct entities in the chondrosarcoma family of tumors.

Malignant glomus tumor: a case report and review of the literature.

This report concerns a malignant glomus tumor, a rare soft tissue tumor that was examined immunohistochemically and ultrastructurally. It occurred in a 44-year-old male patient who had suffered from dull pain and stiffness in the right thigh for 10 months. Radiographic examination revealed a well-defined osteolytic lesion in the diaphysis of the right femur. Hypervascularity of the tumor was observed angiographically. Computed tomographic and magnetic resonance examinations showed an intramuscular mass invading the marrow space of the femur. Wide resection was performed after open biopsy. Histologically, round to polygonal tumor cells revealed a uniform appearance of round to ovoid nuclei with single large nucleoli and slightly eosinophilic cytoplasm, forming solid sheets of cells interrupted by vessels of varying size. A few mitotic figures and vascular invasion were observed. Immunohistochemically, vimentin and alpha-smooth muscle actin were stained intensely, and muscle actin was positive for tumor cells of the perivascular area. Tumor cells were negative for desmin, factor VIII-related antigen, S-100 protein, neurofilament, cytokeratin, and epithelial membrane antigen. Ultrastructurally, tumor cells were characterized by many cytoplasmic processes, pinocytotic vesicles, plasmalemmal dense plaques, and scattered microfilaments in the cytoplasm. Few cell junctions and focal basement membrane-like structures were observed. No recurrence or metastasis was noted 57 months after operation. This case was considered to be a malignant glomus tumor, that is, a glomangiosarcoma arising de novo.

[A clinico-pathologic study of primary malignant fibrous histiocytoma of bone].

Primary malignant fibrous histiocytoma of bone (PBMFH) is a rare tumor. In this series 11 cases of PBMFH (7 men, 4 women, mean age 39.6 years, range 15-62) were reported. They were studied by using morphology, immuno-histochemistry combined with the relevant clinical materials. It showed that most of the patients complained of local pain as the first symptom, and it generally arose in proximal or distal end of extremities. Roentgenographically, it mainly displayed a lytic destruction of bone. Like soft tissue malignant fibrous histiocytoma, it was composed of a mixture of plump fibroblast-like cells and large round or polymorphic histiocyte-like cells and usually showed a storiform pattern. But there were no myxoid and inflammatory subtypes encountered in these cases, except the storiform-pleomorphic type (9 cases) and giant cell type (2 cases). So it appears to have some difference between the subtypes of MFH of bone and soft tissue. Since the histomorphology and immunohistochemical reaction are less characteristic, especially with the morphological pleomorphism and marked cellular heterogeneity, diagnosis of PBMFH must depend on multifacet observation and comprehensive assessment.

Establishment and characterization of a new cell line from a canine osteosarcoma.

A new cell line has been established directly from a spontaneous osteosarcoma on the femur of a 1.5-year-old male mongrel dog and named POS. Doubling time of the cells was approximately 33 hr. Morphologically, spherical cells, fibroblast-like cells, large or small polygonal cells and multinucleated giant cells seemed to be the major component of this cell line. The transmission electron microscopic feature of most of the cells was abundant dilated rough endoplasmic reticulum. Alkaline phosphatase activity as one of the osteoblastic properties was high in this cell line. The tumor tissue produced by the inoculation of the cells into nude mice was histologically identical to the original osteosarcoma.

Ultrastructural appearance of chondroblastoma.

The ultrastructural appearance of two chondroblastoma were examined by scanning and transmission electron microscopy. The polygonal basal cells, with a scanty pericellular matrix, show a poorly developed endoplasmic reticulum and many Golgi bodies. The highly differentiated chondroid cells are assembled in isogenous clusters and show intracytoplasmic inclusions of glycogen and lipids, numerous mitochondria and superficial secretion vesicles arising from a well developed rough endoplasmic reticulum. Clusters of crystals, in close contact with the matrix collagen fibres are found near to the tumour cells. These ultrastructural characteristics, together with the basal undifferentiated cells that proliferate and differentiate into cartilaginous tissue, distinguish this neoplasm from chondroma, mesenchymal chondrosarcoma and chondromyxoid fibroma and confirm its chondroid origin.

[Clinicopathological analysis, immunohistochemical study and electron microscopic observation of chondroblastoma of bone].

A series of 73 cases of chondroblastoma of bone, a rare benign tumor, was subjected to clinicopathological analysis, 50 cases of it were studied by immunohistochemistry and affinity histochemistry and 3 cases were observed by electron microscopy. In this series, chondroblastomas were found nearly in patients of all age groups, with the peak incidence occurring in the second decade of life. The lesions were more commonly located in long bone metaphyseal portion, especially in the upper end of femur and the head and neck of femur. It was easily misdiagnosed as giant cell tumor of bone, chondroma, and osteochondroma by clinic and radiography. There was gradual transition from a few chondroblasts to a small focus of clear cells in 3 cases, therefore, chondroblastoma may transform into clear cell chondrosarcoma by anaplastic change of chondroblast, which is one of malignant chondroblastomas. Our immunohistochemistry and affinity histochemistry results supported the point of view of chondroblast originated from epiphyseal chondrocytes. Immunohistochemical assessment of S-100 protein may be one useful parameter for differentiating chondroblastoma from giant cell tumor of bone and aneurysmal bone cyst ultrastructurally, chondroblasts had characteristic lobulated nuclei, compact zones under nuclear membrane, and microvilli on cells surface. In most cells, the Golgi apparatus and RER were inconspicuous without.

Primitive neuroepithelial tumors with vermiform processes (filiform neuroepithelial tumors). Immunocytochemical and ultrastructural study of 2 cases.

Two unique, poorly-differentiated neuroepithelial tumors are described, one in a 35-year-old woman with an anterior mediastinal tumor and one in a 71-year-old woman with a left femoral mass. Immunocytochemical stains demonstrated Neuron specific enolase in both tumors and Chromogranin in one. Electron microscopy showed the cells of both neoplasms to contain abundant, thick, vermiform, organelle-free processes, previously described solely in large cell lymphomas. Rare dense-core granules were present, and very few processes were suggestive of neurites. These observations enlarge the spectrum of poorly differentiated neuroepithelial tumors.

[Electron microscopic and immunohistochemical studies on chondroblastoma].

Six clinically and patho-histologically proven cases of chondroblastoma were studied with electron microscopic and immunohistochemical methods. The tumor tissues of chondroblastoma exhibited biphasic pattern i.e., chondroid and cellular area. In the chondroid area, small and round tumor cells contained many filaments in the cytoplasm and small processes in the cell wall. Many glycogen granules were present in the tumor cells in some cases. Intercellular matrix was immunohistochemically positive for S-100 protein and showed fine collagen fibers were very similar to those of articular and epiphysial cartilage. Many portions of mitochondria, cell wall and matrix of chondroblastoma tissue clearly exhibited calcification but were not definitely ossification. In the cellular area, tumor cells were composed of small immature mesenchymal and clear large degenerated tumor cells, histiocytes with lysosomes and osteoclast-like multinuclear giant cells. Immunohistochemical studies in the cellular area revealed that there were many tumor cells positive for lysozyme, alpha 1-antitrypsin and alpha 1-antichymotrypsin. In the transitional zone between chondroid and cellular area, degenerated tumor cells were found. The chondroblastoma was composed of chondroid and histiocytic areas which were very similar to those of chondromyxoid fibroma. The present study appears to demonstrate that chondroblastoma originates from a mixture of chondrocytic and histiocytic tumor cells but not from articular and epiphysial cartilage.

[Periosteal osteosarcoma of the femur: a pathological and ultrastructural study].

A femoral, diaphyseal tumor was found in a 17-year old male, and the diagnosis of periosteal osteosarcoma was made, based on the typical radiological and pathological findings. Microscopic observation on a resected specimen revealed that the tumor was covered with the intact periosteal fibrous layer and did not extend beyond the periosteum. The adjacent cortex was free of tumor. These findings indicated that the tumor originated from the periosteal cambium layer, which lies between the periosteal fibrous layer and the cortex. For transmission electron microscopic examination, the tissue was obtained at open biopsy. Ultrastructurally, no specific cell of periosteal osteosarcoma was found. Although most types of osteosarcoma cells were identified in the tumor (osteoblast-like, chondroblast-like, fibroblast-like, primitive mesenchymal-like, osteoclast-like and so on), the ultrastructural characteristics were of wide variety and of low malignancy.

Peripheral chondrosarcoma: ultrastructural investigation by transmission and scanning electron microscopy.

Ultrastructural analysis by transmission and scanning electron microscopy was performed on two grade 1 peripheral chondrosarcomas which had arisen from a preexisting osteochondroma. This analysis allowed us to determine the morphologic changes in both the cell and the matrix and suggested a low grade of malignancy. We emphasize that ultrastructural analysis with scanning and electron microscopy is only valid when conducted on representative areas of the tumor.

[The role of transmission electron microscopy played in diagnosis of knotty tumors].

Eight cases were reported in order to elucidate the important role of electron microscopy (EM) played in diagnosis of knotty tumors. The diagnosis of tumors made by light microscopy (LM) could be confirmed, corrected or eliminated with EM, and the types and histogenesis of tumors could be decided more accurately with EM than with LM. But EM has its inherent limitations, so it is emphasized that diagnosis made by EM must rest on solid basis of LM, and sometimes EM should be combined with other methods, such as histochemistry and immunohistochemistry.

[Osteoid osteoma. A scanning electron microscopic study]. / L'osteoma osteoide. Studio al microscopio elettronico a scansione.

The mineralization process of the osteoid osteoma, after removal of the organic matrix from the specimens by treatment with 6% sodium hypochlorite, has been studied by SEM. The process was characterized by calcified nodules or calcospherites, variable in size from 0,1 to 2 microns, embedded among randomly oriented collagen bundles, which delimited trabeculae of sponge primary bone. Numerous osteocytic lacunae, in various degrees of development, in the mineralizing front were present. The ultrastructural feature of the mineralization in osteoid osteoma reflected a pattern of nodular and collagenous calcification, essentially similar to primary calcification, characteristic of rapidly developing woven bone.

Characterization of osteosarcoma cells from two sibling large-breed dogs.

Neoplastic cells were isolated from 2 sibling Great Dane/Labrador Retriever mixed-breed dogs in which telangiectatic type osteosarcomas arose concurrently. Cells from various sites in the same osteosarcoma appeared similar in culture, but there were differences between the 2 osteosarcomas in growth characteristics and appearance of cells. Cells from 1 osteosarcoma had a small, but significant (P less than 0.05), cyclic adenosine monophosphate response to parathyroid hormone stimulation, indicating a low order of osteoblastic differentiation. Cells from the other osteosarcoma had no response to parathyroid hormone stimulation. Cells from both osteosarcomas and a concentrated cell-free filtrate from the osteosarcoma with osteoblastic differentiation were injected into nude mice, but osteosarcomas were not induced. Results of ultrastructural examination of osteosarcoma samples for viral particles were negative and supernatant fluids from cultured cells were considered negative for viral reverse transcriptase activity.

Clear-cell chondrosarcoma--a case report.

Clear-cell chondrosarcoma, a recently specified entity, is a low-grade malignant tumor and has characteristic clinical, roentgenographic and pathologic findings which separate it from conventional chondrosarcoma and other benign tumors. Therefore, correct diagnosis is important from the viewpoint of both prognosis and therapeutic approach. We report a case of typical recurrent clear-cell chordirosarcoma. Typical round cells with clear cytoplasm, large nuclei, and small nucleoli were wellnoted. The clear cytoplasm was faintly positive in PAS staining. Electronmicroscopic study showed that these cells were of chondroid origin, showing indented nuclei, large dilated endoplasmic reticulum cisternae, bundles of actin-like filaments and a few glycogen particles.

[Osteoid osteoma: ultrastructural aspects]. / L'osteoma osteoide: aspetti ultrastrutturali.

The authors take into consideration the ultrastructural aspects of osteoid osteoma and discuss the cellular and subcellular features of this neoplasm. Special attention is given to functional adaptability, which is specific for this type of cell, related to the degree of development of the neoformation.