Extraskeletal chondroma with chondroblastic and granuloma-like elements.

A unique case of extraskeletal chondroma occurring in the right ring finger of a 51-year-old man is reported. The tumor, measuring 4.0 x 2.2 x 1.5 cm, consisted of chondroid, granuloma-like, and chondroblastic cell zones associated with fine calcification. Immunohistochemically, most of the tumor cells except for multinucleated giant cells were positive for vimentin. Cells positive for S-100 protein were scattered throughout the tumor, and cells positive for alpha-1 antichymotrypsin were observed in the chondroblastic cell zone and in the granuloma-like area. Ultrastructurally, the chondroblastic cells had a characteristic microvillous cell border.

Intracytoplasmic eosinophilic hyaline globules in cartilaginous neoplasms: a surgical, pathological, ultrastructural, and electron probe x-ray microanalytic study.

Hyaline globules (HGs), spherical intracytoplasmic eosinophilic droplets, have been associated with a variety of conditions, including hepatocellular carcinoma, lung adenocarcinoma, and Kaposi's sarcoma, but they have not been described in cartilaginous tumors. In specimens of 60 cartilaginous neoplasms we found that 22 of 33 chondrosarcomas (67%), eight of 16 enchondromas (50%), and three of seven soft tissue chondromas (43%) exhibited HGs. HGs were seen more commonly in low grade chondrosarcoma (70%) and were relatively rare in high grade chondrosarcoma (25%). No HGs were identified in three osteochondromas, one synovial chondromatosis, or 15 normal cartilaginous tissues taken from various sites. Cartilage associated HGs ranged in size from 2 to 20 microns, were diastase resistant and periodic acid-Schiff (PAS) stain positive, demonstrated autofluorescence, and variably stained with Mallory's phosphotungstic acid-hematoxylin stain (PTAH). A panel of immunostains did not show any specific staining reactions with HGs. Ultrastructurally the HGs were spherical, non-membrane-bound bodies having complex architectural features associated with profiles of rough endoplasmic reticulum. Electron probe x-ray microanalytic (EPXMA) study showed significant peaks of sulphur and calcium. We conclude that HGs represent secretory products of probable glycoprotein nature, may accumulate in a variety of cartilaginous neoplasms, and may be seen more frequently in low grade chondrosarcomas.

[A case of chondroma of the cerebello-pontine angle and clivus]. / Przypadek chrzestniaka kata mostowo-mózdzkowego i stoku.

A 42-year old woman with a rare intracranial tumour-chondroma of the cerebello-pontine angle and clivus is presented. Clinical signs of the disease appeared when the tumour attained a huge size. Despite grave postoperative course the prognosis in our patient was good.

Morphometric analysis of cartilaginous tumors.

144 chondromas and chondrosarcomas have been investigated. Morphometry has been performed: the relative volume density of tumor cell nuclei (Vv%n) and the nuclear area have been measured. The results show that the relative volume density of nuclei is a useful parameter, regarding the localisation of the tumors, to discriminate chondromas and chondrosarcomas, while the nuclear area is no safe criterion to separate these entities.

Chondroblastomalike extraskeletal chondroma.

An unusual extraskeletal tumor occurring in the right thumb of a 44-year-old man exhibited histologically a chondroblastomalike appearance. The tumor was characterized by dense proliferation of chondroblastic cells admixed with a few multinucleated giant cells of osteoclast type. The patient had no evidence of local recurrence or metastasis three-and-a-half years after a simple excision.

A morphometric approach to the grading of chondroid tumours on fine-needle smears.

A morphometric study was performed on 600 nuclei from 6 benign chondroid tumours (BCL) (3 enchondromas and 3 exostoses), 600 nuclei from 6 well-differentiated chondrosarcomas (WDC) and 200 nuclei from moderately-differentiated chondrosarcomas (MDC) obtained by fine needle aspiration biopsy. The parameters considered were nuclear area, perimeter and maximum diameter. Moving across the three groups of lesions the nuclei appeared progressively larger. A statistical analysis was performed on the three groups. Significant differences between the means of all the parameters considered were observed. The authors suggest that morphometric analysis may be a possible step in the cytologic diagnosis and grading of chondroid tumours.

Ossifying fibromyxoid tumor of soft parts. A clinicopathological analysis of 59 cases.

We describe 59 cases of a microscopically unique neoplasm that has not been previously reported. The tumor almost exclusively affected adults (range 14-79 years) and had a male predominance (38 men and 21 women). It presented in most cases as a small, painless, well-circumscribed mass (median, 4 cm) in subcutis or muscle. It occurred chiefly in the upper and lower extremities (40 cases) and less frequently in the trunk (11 cases) and the head and neck region (eight cases). Microscopically, the tumor was partly lobulated and composed of small, round cells that had vesicular nuclei and indistinct cytoplasm. Typically, the cells were arranged in a cord- or nestlike pattern within a myxoid matrix that frequently showed transitions toward hyaline fibrosis and focal osteoid formation. In about two-thirds of the cases, the cells contained immunoreactive S-100 protein. An additional typical feature, seen in 48 (81%) of the 59 cases, was the presence of an incomplete shell of mature bone in the capsular region of the tumor. Follow-up information, available in 41 cases, revealed that 11 patients (27%) experienced one or more recurrences. One patient with three recurrences developed a second tumor in the opposite thigh, presumably a metastasis. None of the patients died of the tumor, but three died of causes unrelated to the disease. Although the histogenesis is uncertain, cartilaginous or neural origin seem to be most likely. Until this issue is resolved, we prefer the descriptive and less committal designation of "ossifying fibromyxoid tumor of soft parts."

Synovial chondromatosis of the temporomandibular joint: a light and electron microscopic study.

The light and electron microscopic features of synovial chondromatosis of the temporomandibular joint of one patient are presented. The affected synovial membrane and the cartilaginous nodules, which were freely movable in the joint space as well as attached to or incorporated in the synovial membrane, were examined. Light microscopic observation revealed metaplastic formation of these nodules within the subintima of the synovial membrane. Different stages of development of the nodules were observable. Electron microscopic examination of the cartilaginous nodules revealed features of mature chondrocytes well endowed with rough-surfaced endoplasmic reticulum and Golgi apparatus. The synovial intimal cells had a differentiated ultrastructural appearance. Several cytoplasmic organelles of the chondrocytes and intimal cells are described. The results of this study support the benign nature of synovial chondromatosis.

Histopathology and ultrastructure of tumours and tumour-like lesions of bone.

The monograph summarizes the most important data and experience based on the clinicopathological analysis, histological and histoenzymatic examinations of more than 1000 primary tumours and 400 tumour-like lesions of bones. The diagnosis of them has been based on the WHO classification of bone tumours which appeared to be the best in meeting the needs of diagnostic practice. However, in our collection of cases also occurred such cases which did not fit into the WHO diagnostic scheme. They included lesions the separate existence of which could be proved only recently or has remained the matter of discussion, such as periosteal osteosarcoma, clear-cell and dedifferentiated chondrosarcoma, malignant fibrous histiocytoma, the so-called parachordoma, resorptive giant-cell granuloma, reactive periostitis of tubular bones of hands and feet, and the tibial lesion reminiscent of cementifying fibroma. In the majority of types of the tumours and tumour-like lesions of bones electron microscopical examination was carried out (203 cases), the results of which are presented here in a considerable extent. On the one hand, electron microscopy facilitated the diagnosis in some cases, and, on the other hand, it proved as extremely important in solving the problems of histogenesis of some of the lesions.

A new histologic approach to the differentiation of enchondroma and chondrosarcoma of the bones. A clinicopathologic analysis of 51 cases.

Fifty-one cases of central, hyalin cartilage tumors of the long and flat bones were analyzed. Although Grade 2 and 3 chondrosarcomas could be diagnosed on the basis of cytologic features alone, low-grade chondrosarcoma could not be adequately differentiated from pure, benign enchondroma(s) by cytology alone. The tumors can be distinguished by a new histologic approach based on tissue patterns. The crucial enchondroma patterns consist of multiple nodules of hyalin cartilage separated by normal marrow in conjunction with partial to complete encompassing plates of lamellar bone that conform to the irregular shapes of the cartilage nodules. The chondrosarcomatous patterns consist of a single confluent mass of cartilage, which commonly permeates the marrow, "trapping" host lamellar bone on all sides, and which forms bands of fibrosis between the confluent peripheral cartilage lobules. Other less common patterns included cartilagenous infiltration of the Haversian systems or marrow fat and/or the development of a soft tissue mass. A central secondary chondrosarcoma is defined as one that shows the combination of both the enchondromatous and chondrosarcomatous patterns. All 18 of the pure enchondromas diagnosed by the methods proposed in this article behaved with strict benignity (i.e., without evidence of recurrence or metastasis with an average follow-up period of 7.2 years). The 33 primary and secondary chondrosarcomas diagnosed using the described patterns behaved with the predicted frequency of recurrence, metastasis, and patient demise.

Chondromyxoid fibroma of the maxilla. Electron microscopic findings and review of the literature.

A case of chondromyxoid fibroma of the anterior maxilla is presented. The light and electron microscopic appearances of this tumor are described. A review of chondromyxoid fibromas of the jaws is performed, with a discussion of the appropriate therapy.

Ultrastructure of cartilaginous tumors and S-100 protein in the tumors. With reference to the histogenesis of chondroblastoma, chondromyxoid fibroma and mesenchymal chondrosarcoma.

Twelve cartilaginous tumors were studied by electron microscopy and the presence of S-100 protein was studied immunohistochemically in order to clarify the cell origin of chondroblastoma, chondromyxoid fibroma, and mesenchymal chondrosarcoma. Three chondroblastomas were characterized by round or ovoid tumor cells with some cytoplasmic processes, well-developed organelles and thick fibrous laminae in the nuclear membrane, occasional multinucleated giant cells and scanty chondroid matrix. S-100 protein was demonstrated in the tumor cells and some multinucleated giant cells Two chondromyxoid fibromas revealed tumor cells of varied shapes with characteristic cartilaginous differentiation and abundant chondroid matrix. Spindle tumor cells showed the ultrastructural features of cartilage cells rather than of fibroblasts and S-100 protein was also demonstrated in their cytoplasm. Chondroblastoma and chondromyxoid fibroma were considered to arise from chondrocytes. Mesenchymal chondrosarcoma ultrastructurally exhibited round tumor cells with cartilaginous nature in cartilage islands. Poorly-differentiated portions were composed of primitive round or elongated cells with occasionally admixed round cells with ultrastructural features of cartilaginous differentiation. S-100 protein was demonstrated in the cells in cartilage islands and in single cells admixed in poorly-differentiated portions. These results support the hypothesis of primitive mesenchymal origin with a tendency to differentiate toward cartilage cells.

[Ultrastructural and pathological studies of chondromyxoid fibroma of bone].

Histological and electron microscopic studies were carried out on a chondromyxoid fibroma in the right femur of a 8 years old boy. Although chondromyxoid fibroma contained chondroid, fibrovascular and myxoid components, the chondroid zone was transformed into myxoid zone through degeneration of chondroblastic tumor cells. Fibroblastic tumor cells gave no findings specific for fibroblast and fibrocyte on electron microscopy. Most primitive tumor cells were found in the fibromatoid zone. These cells have probably differenciated to fibroblastic and chondroblastic tumor cells. Histiocytes were gathered around the blood vessel. Despite the native of chondromyxoid fibroma as one of the bone tumor of cartilagenous deviation, it showed the characteristics of histiocytic tumors in part.

Chondromyxoid fibroma of the iliac bone: a case report with ultrastructural observations.

Ultrastructural findings in an unusual case of chondromyxoid fibroma are reported. The tumor was located in the iliac bone of a 42-year-old woman with left hip pain of 5 years duration.

Ultrastructure of solitary enchondromas.

Solitary enchondromas obtained from the small bones of the hand were studied with transmission electron microscopy. Three cell types were seen as follows: (1) young looking, active cells with extensive dilated rough endoplasmic reticulum and well defined Golgi and mitochondria; (2) older looking, degenerating cells with dilated rough endoplasmic reticulum, well defined Golgi, glycogen masses, vacuoles containing tropocollagen, lipid and myelin figures; and (3) dying cells showing loss of cell membrane and lysosomal-like bodies. A young chondroblastic cell may try to mature, become a normal chondrocyte that produces normal matrix but it does not succeed and dies. Enchondromal cells are not capable of forming tropocollagen or synthesizing proteoglycans for the matrix.

Chondroid chordoma. Electron-microscopic study of two cases.

Chondroid chordoma is an unusual tumor composed of an admixture of chondromatous and chordomatous tissue usually located in the spheno-occipital region. This tumor shares many of the clinical and histologic features of classic chordoma and chondrosarcoma and has been shown to have a better prognosis than either of these lesions. To the best of our knowledge, no ultrastructural studies have been performed in the 26 cases of chondroid chordoma published previously. We document the ultrastructural features of two examples of chondroid chordoma. Certain features such as prominent and dilated rough endoplasmic reticulum, intracytoplasmic glycogen aggregates, and abundant fibrillogranular matrix are common to chordoma, chondrosarcoma, and chondroid chordoma. The presence of well-formed tonofilament desmosome complexes as well as complexes composed of alternating profiles of rough endoplasmic reticulum and mitochondria were seen only in chordoma and chondroid chordoma, but not in cartilaginous tumors. Of particular interest was the finding of crystalline, tubular structures within the rough endoplasmic reticulum of both cases of chondroid chordoma, a finding not described previously. The distinction of chondroid chordoma from classical chordoma is said to be a difficult one at the light-microscopic level, and we suggest that these intraergastoplasmic tubular structures might constitute an extremely helpful differential marker.