Can MR imaging challenge the commonly accepted theory of the pathogenesis of solitary enchondroma of long bone?

OBJECTIVE: It has been widely postulated that enchondromas arise from cartilage remnants that have been displaced from the growth plate into the metaphysis. However, this theory remains unproven. Based on the common occurrence of enchondromas on routine knee MR imaging (2.9 %), one would expect to find displaced cartilage in the metaphysis of skeletally immature individuals on routine knee MR examinations if the above theory was to be supported. MATERIALS AND METHODS: The electronic databases of a specialist orthopedic hospital and children's hospital were searched for skeletally immature patients who underwent MR imaging of the knee for a variety of indications. Individuals with Ollier disease or hereditary multiple exostoses were excluded. The MR images were subsequently reviewed by a musculoskeletal radiologist for evidence of displaced cartilage into the metaphysis. RESULTS: We reviewed 240 MR examinations of the knee that were performed in 209 patients. There were 125 MR studies in male and 115 MR examinations in female patients (age range: 5 months-16 years; median age: 13 years). In 97.1 %, the growth plates around the knee demonstrated a regular appearance. Seven cases (2.9 %) in six patients showed cartilage extension from the growth plate into the metaphysis, which remained in continuity with the growth plate. There were no cases of displaced cartilage into the metaphysis on MRI. CONCLUSIONS: Our study challenges the widely believed theory that enchondromas arise from displaced growth plate remnants.

Prognostic factors and metastatic patterns in primary myxoid/round-cell liposarcoma.

Background. This study aimed to investigate prognostic factors for patients with myxoid/round-cell liposarcoma (MRCLS), in particular the significance of the round cell component, and to identify metastatic patterns as well as possibly suggest a suitable strategy for followup. Methods. Clinical, morphologic, and follow-up data from 160 patients with MRCLS was reviewed and statistically analysed. Results. Of 130 tumours with the round cell component evaluated, 61 had no round cell component, 27 had <5% round cell component, and 42 had >5%. All patients underwent surgical excision, 15 requiring amputation. 107 patients received adjuvant radiotherapy. Local recurrence occurred in 19 patients (12%), predominantly in patients with marginal or intralesional margins and a round cell component. Overall disease specific survival was 75% at 5 years and 56% at 10 years and was related to the proportion of round cell component. Of 52 patients who developed metastases, 38 (73%) had purely extrapulmonary metastases. We could not identify any factors predicting the site of metastases developing. Conclusions. The occurrence of any round cell component is the most important adverse prognostic factor for patients with MRCLS; patients with >5% round cell component are at higher risk of local recurrence, metastasis and tumour-related death and should be considered for adjuvant radiotherapy and possibly chemotherapy. The best method of monitoring extrapulmonary metastases remains to be established.

Giant cell tumour of the triquetrum.

We present details of a case of giant cell tumour of bone (GCTOB) involving the triquetrum. GCTOB arising within the carpus is exceedingly rare and, to our knowledge, this is only the second case of monostotic GCTOB of the triquetrum that has been reported.

Fusion of the EWS-related gene TAF2N to TEC in extraskeletal myxoid chondrosarcoma.

Extraskeletal myxoid chondrosarcomas (EMCs) are characterized by a recurrent t(9;22)(q22;q12) translocation, resulting in the fusion of the EWS gene in 22q12 and the TEC gene in 9q22. Here we report that a third member of the EWS, TLS/FUS gene family, TAF2N, can replace EWS as a fusion partner to TEC in EMC. Two tumors, one with a novel t(9;17)(q22;q11) variant translocation and one with an apparently normal karyotype, expressed TAF2N-TEC fusion transcripts. In both cases, the chimeric transcripts were shown to contain exon 6 of TAF2N fused to the entire coding region of TEC. This transcript is structurally and functionally very similar to the EWS-TEC fusions. The exchange of the EWS NH2-terminal part with the TAF2N NH2-terminal part in EMC further underscores the oncogenic potential of these protein domains as partners in fusion genes.

Fusion of the NH2-terminal domain of the basic helix-loop-helix protein TCF12 to TEC in extraskeletal myxoid chondrosarcoma with translocation t(9;15)(q22;q21).

Extraskeletal myxoid chondrosarcomas (EMCs) are characterized by recurrent t(9;22) or t(9;17) translocations resulting in fusions of the NH2-terminal transactivation domains of EWS or TAF2N to the entire TEC protein. We report here an EMC with a novel translocation t(9; 15)(q22;q21) and a third type of TEC-containing fusion gene. The chimeric transcript encodes a protein in which the first 108 amino acids of the NH2-terminus of the basic helix-loop-helix (bHLH) protein TCF12 is linked to the entire TEC protein. The translocation separates the NH2-terminal domain of TCF12 from the bHLH domain as well as from a potential leucine zipper domain located immediately downstream of the breakpoint. These results demonstrate that the NH2-terminal transactivation domains of EWS or TAF2N are not unique in their ability to convert the TEC protein into an oncogenically active fusion protein, and that they may be replaced by a domain from a bHLH protein that presumably endows the fusion protein with similar functions.

A link between basic fibroblast growth factor (bFGF) and EWS/FLI-1 in Ewing's sarcoma cells.

The EWS/FLI-1 fusion gene is characteristic of most cases of Ewing's sarcoma and has been shown to be crucial for tumor transformation and cell growth. In this study we demonstrate a drastic down-regulation of the EWS/FLI-1 protein, and a growth arrest, following serum depletion of Ewing's sarcoma cells. This indicates that growth factor circuits may be involved in regulation of the fusion gene product. Of four different growth factors tested, basic fibroblast growth factor (bFGF) was found to be of particular significance. In fact, upon treatment of serum-depleted cells with bFGF, expression of the EWS/FLI-1 protein and growth of the Ewing's sarcoma cells were restored. In addition, a bFGF-neutralizing antibody, which was confirmed to inhibit FGF receptor (FGFR) phosphorylation, caused down-regulation of EWS/FLI-1. Experiments using specific cell cycle blockers (thymidine and colcemide) suggest that EWS/FLI-1 is directly linked to bFGF stimulation, and not indirectly to cell proliferation. We also demonstrated expression of FGFRs in several tumor samples of Ewing's sarcoma. Taken together, our data suggest that expression of FGFR is a common feature of Ewing's sarcoma and, in particular, that the bFGF pathway may be important for the maintenance of a malignant phenotype of Ewing's sarcoma cells through up-regulating the EWS/FLI-1 protein. Oncogene (2000) 19, 4298 - 4301

Amplification and overexpression of the hepatocyte growth factor receptor (HGFR/MET) in rat DMBA sarcomas.

In the present study subcutaneous fibrosarcomas were induced by the carcinogen 7,12-dimethylbenz(a)anthracene (DMBA) in rats from F1 generation cross breedings of two different inbred strains. Comparative genomic hybridization (CGH) analysis, which allows detection of DNA sequence copy changes, was applied to one of the tumors and it was found that there were increased copy numbers of sequences at chromosome 4q12-q21 in this tumor. We have previously determined that the loci for the hepatocyte growth factor (Hgf) and hepatocyte growth factor receptor (Hgfr/Met), a protooncogene, are situated in this particular chromosome region. Using probes for the two genes in FISH (fluorescence in situ hybridization) and in Southern blots we found that the Hgfr/Met gene was amplified in five of the 19 sarcomas studied, and that the Hgf gene was coamplified in two of them. Northern and Western blots and tyrosine phosphorylation analysis showed that the HGF receptor was overexpressed and functional in all five tumors, as well as in two additional tumors. In summary, both amplification and overexpression of the Hgfr/Met gene was found in about 25% of DMBA-induced experimental rat sarcomas, and HGF receptor overexpression alone was seen in two additional tumors. Possibly this reflects an involvement in paracrine or autocrine stimulation of growth and invasiveness by HGF. Our finding could provide a rodent model system to increased knowledge about causality and therapy, which may be applicable to the sizeable fraction of human musculoskeletal tumors displaying MET overexpression.

Expression and localization of estrogen receptor-beta in murine and human bone.

Estrogens have profound effects on bone metabolism. Cellular responses to estrogens are mediated by estrogen receptors (ERs) which belong to the nuclear receptor superfamily. Two estrogen receptors, ERalpha and ERbeta, have been cloned. Previously expression of ERalpha has been shown in osteoblasts. Here we demonstrate that the transcript for ERbeta can be detected in the human osteosarcoma cell lines (MG-63 and SaOS-2) and in cultured human osteoblast-like cells. We also show that ERbeta protein is present in nuclear extracts from these cells. Furthermore, ERbeta immunoreactivity is found in sections of murine and human bone. Murine and human osteoblast and osteocyte nuclei are immunoreactive for ERbeta. Osteoclasts are also ERbeta immunoreactive but the staining is mainly cytoplasmic. The present study demonstrates that ERbeta is present in all the cellular compartments involved in bone formation and bone resorption, both in human and in murine bone tissue.

A founder mutation of the BRCA1 gene in Western Sweden associated with a high incidence of breast and ovarian cancer.

The aim of this study was to describe and characterise a founder mutation of the BRCA1 gene in western Sweden. Of 62 families screened for BRCA mutations, 24 had BRCA1 mutations and two had BRCA2 mutations. Tumours that occurred in family members were histologically reviewed and mutational status was analysed using archival paraffin-embedded tissues. The same BRCA1 mutation, 3171ins5, was found in 16 families who were clustered along the western coast of Sweden. Mutation analysis revealed a maternal linkage in 13 families and a paternal linkage in 3. There was complete agreement between mutation analysis results obtained from blood and archival tissues. The penetrance of breast or ovarian cancer by age 70 years was estimated to be between 59 and 93%. There were no differences in survivals between breast or ovarian cancer patients with the mutation and age-matched controls. Thus, a predominant BRCA1 gene founder mutation associated with a high risk of breast and ovarian cancer has been identified and found to occur in a restricted geographical area, thereby allowing timely and cost-effective mutation screening using blood samples or archival histological material.

Acral myxoinflammatory fibroblastic sarcoma: a low-grade tumor of the hands and feet.

Acral myxoinflammatory fibroblastic sarcoma is a unique low-grade tumor of modified fibroblasts. It characteristically occurs in the distal extremities and has a propensity to recur locally. Forty-four cases that occurred in 22 males and 22 females from 20 to 91 years of age (median, 53 years) were studied. The lesions, which were 1-6 cm (median, 3 cm), occurred in the hands (64%), the feet (20%), the ankles (11%), and the wrists (5%). The patients usually had a long history of a painless mass (median duration, 1 year). Clinically they were suspected to be ganglion cysts, tenosyonovitis, or giant cell tumors of tendon sheath. Initial histologic diagnoses, in most cases, included pigmented villonodular tenosynovitis or various reactive fibroinflammatory processes. Histologically, the lesions were multinodular, poorly delineated, and characterized by a prominent myxoid matrix containing numerous inflammatory cells, including polymorphonuclear leukocytes, eosinophils, lymphocytes, and plasma cells, as well as fibrosis. Amidst the prominent inflammation, and sometimes obscured by it, were scattered, large, bizarre tumor cells with vesicular nuclei, prominent inclusion-like nucleoli, and abundant eosinophilic cytoplasm, which was homogeneous to vacuolated and often contained intracytoplasmic inflammatory cells. Ultrastructurally, the bizarre tumor cells had features of modified fibroblasts, including an abundance of intermediate filaments and dilated rough endoplasmic reticulum. Immunohistochemically, the neoplastic cells revealed strong positivity for vimentin (25 of 25), focal positivity for CD68 antigen (17 of 25) and CD34 (7 of 25); the tumor cells did not express neuroectodermal, epithelial, or lymphoid markers. The Ki67 labeling index with MIB1 was less than 1% in 20 of 25 cases; p53 immunoreactivity (20-90%) was observed in 7 of 25 primary tumors and in 2 of 3 local recurrences. Follow-up information was available in 36 of 44 cases (median, 5 years). Most excisions were either intralesional or marginal. Ten patients underwent amputation, usually after repeated local recurrences. Radiation therapy and chemotherapy were administered in five and two cases, respectively. Twenty-four cases (67%) had at least one local recurrence. A histologically proven lymph node metastasis developed in one patient, whereas another was stated to have lung metastases, although these were not documented histologically. At last follow-up, 23 patients were alive and well, 11 were alive with disease, and 2 were dead of other causes without evidence of tumor. The prominent inflammation and fibrosis seen histologically in acral myxoinflammatory fibroblastic sarcoma simulate a reactive process. The presence of myxoid foci and scattered bizarre cells, which are occasionally multivacuolated, may cause confusion with malignant fibrous histiocytoma and liposarcoma. Based on the protracted clinical course, a high rate of local recurrence (sometimes necessitating amputation), and a low rate of metastasis, we believe these tumors are low-grade sarcomas. The intimate relationship with the synovium, the frequent association with tenosynovitis, and the prominent inflammatory infiltrate suggest that inflammation may play a role in the pathogenesis of acral myxoinflammatory fibroblastic sarcoma.

Angiosarcoma of soft tissue: a study of 80 cases.

The clinicopathologic, immunohistochemical, and ultrastructural features of soft tissue angiosarcomas are not well defined. Eighty cases of angiosarcoma that involved the deep subcutis, skeletal muscle, retroperitoneum, mesentery, and mediastinum are reported. The lesions occurred in 50 male and 30 female patients who were 5-97 years of age; the peak incidence was in the seventh decade of life. A variety of associated conditions were documented in 20 of these cases, including a history of other neoplasms (some irradiated), synthetic vessel grafts, heritable conditions, and prior trauma or surgery. The angiosarcomas occurred in the extremities (n = 43 cases), trunk (n = 28), and the head and neck (n = 9) regions, with the thigh and the retroperitoneum being the most common sites. They often were characterized as enlarging, painful masses of several weeks' duration and were occasionally associated with acute hemorrhage, anemia, or a coagulopathy. The tumors measured 1-15 cm in diameter (median 5 cm) and frequently were hemorrhagic and multinodular. There was a wide morphologic spectrum within and between cases, including areas similar to cavernous and capillary hemangioma, Dabska tumor, spindle cell and epithelioid hemangioendothelioma, various spindle cell sarcomas, or carcinoma. Histologically, epithelioid angiosarcoma was the most frequently observed pattern; 70% of cases had epithelioid cells that were arranged in nests, clusters, papillae, and gaping vascular channels. Hemorrhage tended to obscure the diagnosis in several cases and often was associated with papillary endothelial hyperplasia-like areas. All 42 cases studied immunohistochemically stained at least focally for Factor VIII-related antigen, and nearly all stained strongly for vimentin, which accentuated the endothelial cells and vessel lumen formation. CD34 antigen was detected in 74% of cases, BNH9 in 72%, and cytokeratins in 35%. Epithelial membrane antigen, S-100 protein, and HMB45 were not detected. Fifty-five percent of the tumors had intracytoplasmic aggregates of laminin. Immunostains for alpha-smooth muscle actin demonstrated a prominent pericytic component in several tumors (24%). Ki67 immunostains with MIB1 indicated high proliferative activity (> or =10%) in 72% of cases. p53 immunoreactivity (>20% nuclear staining) was observed in 20% of cases. Ultrastructural studies performed on poorly differentiated areas of 12 cases showed groups of cells, which were frequently epithelioid, surrounded by basal lamina, and closely associated with pericytes, along with intercellular and intracellular lumina with or without red blood cells. Whorls of abundant intermediate filaments, occasional tonofilamentlike structures, and pinocytotic vesicles also were noted. In contrast to the findings of others, Weibel-Palade bodies were not seen. Follow-up in 49 cases (61%) showed that 53% of patients were dead of disease at a median interval of 11 months, whereas 31% had no evidence of disease at a median interval of 46 months. The remaining patients were either alive with disease (14%) or alive but disease status was unknown (2%). There were local recurrences in 20% of cases and distant metastases in 49%, most frequently to the lungs, followed by the lymph nodes, soft tissues, bone, liver, and other sites. These results indicate that angiosarcoma of soft tissue is a high-grade sarcoma. Older patient age, tumor location in the retroperitoneum, and larger tumor size as well as detection of MIB1 in > or =10% of the tumor cell population were all associated with a poorer prognosis.

Atypical hemangioendothelioma of venous origin. A clinicopathologic, angiographic, immunohistochemical, and ultrastructural study of two endothelial tumors within the concept of histiocytoid hemangioma.

Two patients, a 62-year-old man and a 50-year-old woman, both with deep-seated atypical endothelial tumors within the wide concept of histiocytoid hemangioma, are reported. In case 1, the tumor involved the brachial vein, and, in case 2, a medium-sized vein of the anterior neck. In both cases the involved vein was occluded. Angiography in case 1 suggested a tumor that was enclosed by the same fibrous sheath, the conjunctiva vasorum, that enclosed the occluded vein and its concomitant artery. Both tumors were solid, without conspicuous vascular differentiation by light microscopy. Such differentiation, however, was evident from the electron-microscopic examination, which showed tumor cells with endothelial features forming primitive vascular structures. Positive lectin histochemistry (Ulex Europeus I) and positive immunohistochemistry for factor-VIII-related antigen, actin, and vimentin also gave strong support for the endothelial differentiation of the tumor cells. Immunohistochemical studies of markers for histiocytic (alpha 1-antitrypsin, ferritin, lysozyme), epithelial (cytokeratin, epithelial membrane antigen), and neuroectodermal (S-100 protein) and skeletal muscle (myoglobin) differentiation were negative. At follow-up, after 7 years and 2 years, respectively, there were no signs of local recurrence or metastasis.

Sclerosing epithelioid fibrosarcoma. A variant of fibrosarcoma simulating carcinoma.

We report 25 cases of a peculiar sclerosing epithelioid variant of fibrosarcoma (SEF) simulating an infiltrating carcinoma. The tumors occurred primarily in the deep musculature and were frequently associated with the adjacent fascia or periosteum. The patients' ages were 14 to 87 years (median, 45). Fourteen were male and 11 female. The tumors were located in the lower extremities and limb girdles (12 cases), trunk (9), upper limb girdles (2), and neck (2). They measured 2 to 14.5 cm in greatest dimension (median size, 7 cm) and were gray to white and firm. Histologically, the lesions were characterized by a proliferation of rather uniform, small, slightly angulated, round to ovoid epithelioid cells with sparse, often clear cytoplasm arranged in distinct nests and cords. In all cases there was prominent hyaline sclerosis, sometimes reminiscent of osteoid or cartilage and foci of conventional fibrosarcoma. Occasional myxoid zones with cyst formation and foci of hyaline cartilage, calcification, and metaplastic bone were also seen. Mitotic figures were generally scarce. Vimentin was detected in 13 of 14 cases, epithelial membrane antigen in seven, S100 protein in four, and neuron-specific enolase in two. Cytokeratins were detected with AE1/AE3 and CAM 5.2 in two cases. Leukocyte common antigen, CD68 antigen, HMB45, desmin, and alpha-smooth muscle actin were negative in all cases. In 13 of 14 cases, 75% or more of the cells stained for proliferating cell nuclear antigen (PCNA). Ki67 immunostaining with MIB 1 showed low proliferative activity in all cases, averaging 5% of tumor cells or less. In all cases, p53 was detected by immunohistochemical methods; bcl-2, an antiapoptosis marker, was detected in more than 90% of the cells in 11 of 12 cases. Ultrastructurally, both the epithelioid and spindled tumor cells had features of fibroblasts. Follow-up in 16 cases ranging from 13 months to 17 years 3 months (median, 11 years 4 months) revealed persistent disease or local recurrences in 53% of patients and metastases in 43%. The metastases were to the lungs (4 cases), skeleton (3), chest wall/pleura (3), pericardium (1), and brain (1). Four patients died of disease, four were alive with disease, two were known to be alive but disease status unknown, and six had no evidence of further disease at last follow-up. The data suggest that SEF is a relatively low-grade fibrosarcoma; yet it is fully malignant despite the presence of histologically benign-appearing foci. The proliferation markers PCNA and Ki67 did not correlate with prognosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Extraskeletal myxoid chondrosarcoma: a reappraisal of its morphologic spectrum and prognostic factors based on 117 cases.

Extraskeletal myxoid chondrosarcoma (EMC), a phenotypically and genotypically distinctive entity, has generally been viewed as a low-grade sarcoma. No studies regarding clinical and morphologic prognostic factors have been performed on a large series of cases with long-term follow-up because of the rarity and protracted clinical course of EMC. The clinical, morphologic, and immunohistochemical features of 117 previously unreported cases were studied and statistically analyzed. The male-to-female ratio was 2:1. The median patient age was 52 years (range, 6-89 years), and the median tumor size was 7 cm (range, 1.1-25 cm). All tumors occurred within the deep subcutis or deeper soft tissues, with 80% occurring in the proximal extremities or limb girdles and 20% in the trunk. Most initial tumor excisions were intralesional or marginal. Follow-up information was available in 99 cases (median, 9 years: range, 2 months-22 years). Forty-eight patients were disease-free, and 41 patients had evidence of disease (18 of these had died of disease). Ten additional patients survived, but their disease status was unknown. There were local recurrences in 40 (48%) of 83 patients, 23 (58%) of whom had multiple local recurrences. Metastases occurred in 35 (46%) of 76 patients. The estimated 5-, 10-, and 15-year survival rates were 90%, 70%, and 60%, respectively. All cases had histologic features characteristic of classical EMC, at least focally. Cellular foci devoid of myxoid matrix and reminiscent of chondroblastoma, Ewing's sarcoma, monophasic and poorly differentiated synovial sarcoma, fibrosarcoma, and rhabdoid tumor were identified in 29% cases. Older patient age, larger tumor size, and tumor location in the proximal extremity or limb girdle were adverse prognostic factors identified by multivariate analysis. Metastasis also adversely affected survival, although local recurrence did not. This study shows that EMC has a unique clinical course, including a high rate of local recurrence, prolonged survival after metastasis in some cases, and eventually a high rate of death due to tumor. These features distinguish EMC from low-grade sarcomas. This study shows that histologic grading is of no prognostic value in EMC because prognosis is dictated primarily by certain clinical features. Histologic recognition of classical EMC and cellular and solid, nonmyxoid variants is important, however, in view of EMC's distinctive biologic behavior.

Benign epithelioid schwannoma.

Benign schwannoma (neurilemoma) has various morphologic patterns that may cause problems in differential diagnosis. Although an epithelioid variant of malignant schwannoma simulating carcinoma and melanoma is well recognized, a benign counterpart has not yet been defined. In the current study, we describe five cases of benign epithelioid schwannoma that were in the subcutis (four cases) and the neck of the urinary bladder (one case). The tumors occurred in adults 28-73 years of age, were 1-4.5 cm in diameter, were well circumscribed and cellular, and were composed of epithelioid cells arranged in cords and nests. The benign nature of the lesions was evident by a constellation of features, including small size, sharp circumscription, bland morphology, low proliferative activity (four of five had < or =1% Ki67 immunostaining), and a benign clinical course after either marginal or intralesional excision. All cases had some features of classic schwannoma light microscopically and a high degree of Schwann cell differentiation both ultrastructurally and immunohistochemically. The recognition of benign epithelioid schwannoma is important because it may be misinterpreted as a malignant neuroectodermal, mesenchymal, epithelioid, or melanocytic tumor.

Malignant granular cell tumor of soft tissue: diagnostic criteria and clinicopathologic correlation.

Seventy-three cases of malignant, atypical, and multicentric granular cell tumors of soft tissue were studied to clarify criteria for malignancy and prognostic factors. Six histologic criteria were assessed: necrosis, spindling, vesicular nuclei with large nucleoli, increased mitotic activity (> 2 mitoses/10 high-power fields at 200x magnification), high nuclear to cytoplasmic (N:C) ratio, and pleomorphism. Neoplasms that met three or more of these criteria were classified as histologically malignant; those that met one or two criteria were classified as atypical; and those that displayed only focal pleomorphism but fulfilled none of the other criteria were classified as benign. Hence, 46 cases were classified as histologically malignant, 21 as atypical (3 were multicentric), and 6 as benign (all were multicentric). The patients with benign multicentric and atypical granular cell tumors had no metastases and there were no tumor deaths. In contrast, 11 of 28 patients (39%) with malignant granular cell tumor with follow-up information died of disease at a median interval of 3 years; 8 of 28 (29%) were alive with disease, and 9/28 (32%) were disease free (median intervals, 2 and 7 years, respectively). There were local recurrences in 9 of 28 malignant cases (32%) and metastases in 14 of 28 (50%) (median intervals, each 2 years). Forty-eight cases were studied immunohistochemically; 100% expressed vimentin, 98% S-100 protein, 98% neuron-specific enolase, 69% CD57, and 65% CD68. Alpha-smooth muscle actin, desmin, epithelial membrane antigen (EMA), cytokeratins (with CAM 5.2 and KL-1), chromogranin, and HMB45 were not detected. The proliferative index with Ki67 (MIB 1) was 10-50% in 14 of 25 malignant tumors (56%), and immunostaining for p53 was detected in 50% or more of tumor cells in 17 of 25 (68%); both of these factors were statistically significant with regard to the histologic classification as benign, atypical, or malignant. Ultrastructural examination of 13 benign, atypical, and malignant granular cell tumors showed engorgement of the cytoplasm with complex granules and lysosomes, as well as Schwannian features. By flow cytometric DNA analysis, two of six malignant tumors were aneuploid, two were hyperdiploid, and two were diploid. One atypical tumor was aneuploid and all 11 benign tumors were either diploid (9 cases) or hyperdiploid (2 cases). Statistically significant adverse prognostic factors with regard to survival included local recurrence, metastasis, larger tumor size, older patient age, histologic classification as malignant, presence of necrosis, increased mitotic activity, spindling of tumor cells, vesicular nuclei with large nucleoli, and Ki67 values greater [corrected] than 10%. This study defines clinical and morphologic criteria for malignancy in granular cell tumors and shows that malignant granular cell tumor is a high-grade sarcoma with a high rate of metastases and a short survival.

Soft tissue sarcoma after treatment for breast cancer.

In a register study all women in the West of Sweden Health Care Region with a breast cancer diagnosed between 1960 and 1980 (n = 13,490) were followed up in the Swedish Cancer Register to the end of 1988 for later occurrence of a soft tissue sarcoma (STS). Nineteen sarcomas were reported, whereas 8.7 were expected and the relative risk (RR) was 2.2 (CI 95% 1.3-3.4). The absolute risk was 1.7/10(4) person years (PY) in comparison with 0.8 expected. To obtain a more detailed analysis of the associations between arm lymphoedema, radiotherapy and STS development, and to control the quality of the register data, a case control study was also performed. Clinical records from the different hospitals in the region were collected for all the 19 cases as well as for three selected controls per case. The histopathology of the cases were reviewed, and one of the cases was reclassified as a malignant melanoma and excluded from further analysis. Thirteen of the cases were clustered around the treated breast area. To quantify the exposure to radiotherapy, the integral dose was estimated. The presence of lymphedema was included as a binary variable in the analysis. The exact conditional randomisation test indicated a significant correlation between the integral dose and the development of an STS (p = 0.008) and this association was still significant after stratification for arm oedema. A conditional logistic regression analysis with STS as the dependent variable and the integral dose as the explanatory variable gave an odds ratio (OR) of 5.2/100 J (CI 95% 1.3-21.2), and if this regression was restricted only to the STS developing in the radiation fields the OR was 3.2/100 J (CI 95% 0.8-12.9). Thus, the excess of STS in this breast cancer cohort was very low (0.9/10(4) PY). However the integral dose correlates well to the development of STS and can be useful in quantifying even small risks of secondary malignancies in the breast cancer population.

Fine-needle aspiration biopsy in the preoperative diagnosis of chordoma: a study of 17 cases with application of electron microscopic, histochemical, and immunocytochemical examination.

The cytologic findings in a series of 17 patients with chordoma (one clivus, three cervical, one lumbar, and 12 sacral tumors), all of whom underwent fine-needle aspiration biopsy (FNAB) in the preoperative investigation, were studied. Cytologically, three main cell types were recognized: large, mononucleated or binucleated physaliferous cells with a vacuolated "bubbly" cytoplasm; small, rounded, uniform cells; and short spindle-shaped cells. The May-Grünwald-Giemsa staining was found superior to Papanicolaou staining in demonstrating the mucoid matrix and the vacuolated cytoplasm of the physaliferous tumor cells. Ultra-structurally, the tumor cells contained prominent bundles of filament of the intermediate type, as well as large vacuoles and lumina often bordered by microvillous projections; the cells were connected to one another by well-developed desmosomes. The resin embedding technique for the light and electron-microscopic examination of FNAB material (eight cases), the histochemical demonstration of sulphated glucosaminoglycans in the matrix (four cases), and the immunocytochemical analysis (four cases) with positivity for cytokeratin, epithelial membrane antigen, vimentin, and S-100 protein and negativity for carcinoembryonic antigen were found to be of value for the cytologic diagnosis of chordoma, and helped in distinguishing it from other chondrogenic tumors and metastatic mucous-producing carcinoma. From this study we conclude that a preoperative diagnosis of chordoma can be reached by FNAB, provided the findings are carefully evaluated in relation to the clinical and roentgenographic findings. Adjunctive histochemical, immunocytochemical, and ultrastructural techniques applied on the FNA material may be helpful in reaching a conclusive diagnosis when differential diagnostic problems occur.

Lipomatous tumors: a correlative cytologic and histologic study of 27 tumors examined by fine needle aspiration cytology.

A correlative cytologic and histologic study of 12 benign lipomatous tumors and 15 liposarcomas (well-differentiated, myxoid, round cell, and pleomorphic) is presented. In two cases the fine needle aspiration material was embedded in Epon for light and electron microscopic examination. Good correlation was found between the histologic and cytologic findings in the fine needle aspiration material. Pitfalls in the cytologic diagnosis of regressively changed lipoma, intramuscular lipoma, angiolipoma, hibernoma, and lipoblastoma, which may lead to an erroneous diagnosis of liposarcoma, are illustrated. The cytologic appearances of the liposarcomas varied with histologic type, although in all of these tumors the main criterion was the presence of atypical multivacuolated lipoblasts with characteristically scalloped nuclei. Staining of the aspirated material with Alcian blue at varying pH levels for characterization of the glycosaminoglycan content may help in the distinction of myxoid liposarcomas from myxoid chondromatous tumors and chordomas. May-Grünewald-Giemsa staining is considered the most useful staining method, while fat staining is considered of limited or no value in the cytologic diagnosis of lipomatous tumors. Epon embedding of fine needle aspirates for light and electron microscopic examination seems to be a useful diagnostic technique.

Chondroid lipoma: an ultrastructural and immunohistochemical analysis with further observations regarding its differentiation.

Chondroid lipoma was recently described as a unique, benign, pseudosarcomatous lipomatous tumor with chondroid features, often simulating liposarcoma and myxoid chondrosarcoma. An extended histochemical and immunohistochemical analysis of 13 cases, including the proliferation markers, proliferating cell nuclear antigen (PCNA) and Ki67, as well as ultrastructural studies of eight cases were performed with the intent of further elucidating its differentiation. Staining with toluidine blue and alcian blue at controlled pHs indicated the presence of chondroitin sulfates within the myxohyaline matrix. Immunohistochemically, all tumors were positive for vimentin and S100 protein. Focal immunoreactivity for cytokeratins was seen in 3 of 13 cases; one of these also had intracytoplasmic tonofilament bundles ultrastructurally. Scattered tumor cells stained for CD68 antigen with KP1 in 6 of 13 cases. None of the tumors stained for epithelial membrane antigen (EMA) or alpha-smooth muscle actin. Collagen IV immunostains showed a network of fibrils encircling individual tumor cells in 10 of 13 cases. Intracytoplasmic staining for laminin was found in 9 of 13 cases. Ultrastructurally there was a spectrum of differentiation, ranging from primitive cells sharing features of prelipoblasts and chondroblasts, to lipoblasts and preadipocytes, to mature adipocytes. A striking ultrastructural feature in 5 of 8 cases was the presence of knob-like protrusions of the cell membrane, which contained granular, amorphous, and fibrillar material that appeared to be extruded into the adjacent matrix. The myxohyaline matrix had ultrastructural features of cartilage. Numerous mitochondria and lysosomes were absent, indicating that chondroid lipoma is neither a hibernomatous lesion nor a lipogranuloma. Ki67 immunoreactivity was typically very low and detected only in the more primitive cell population. The findings in this analysis indicate that chondroid lipoma is a pseudosarcomatous lipogenic neoplasm with a unique cell population possessing predominantly features of embryonal fat and, to a lesser extent, embryonal cartilage.