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PubMed2002

Performance characteristics of a reverse transcriptase-polymerase chain reaction assay for the detection of tumor-specific fusion transcripts from archival tissue.

Pediatric small round cell tumors still pose tremendous diagnostic problems. In difficult cases, the ability to detect tumor-specific gene fusion transcripts for several of these neoplasms, including Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/PNET), synovial sarcoma (SS), alveolar rhabdomyosarcoma (ARMS), and desmoplastic small round cell tumor (DSRCT) using reverse transcriptase-polymerase chain reaction (RT-PCR), can be extremely helpful. Few studies to date, however, have systematically examined several different tumor types for the presence of multiple different fusion transcripts in order to determine the specificity and sensitivity of the RT-PCR method, and no study has addressed this issue for formalin-fixed material. The objectives of this study were to address the specificity, sensitivity, and practicality of such an assay applied strictly to formalin-fixed tissue blocks. Our results demonstrate that, for these tumors, the overall sensitivity for detecting each fusion transcript is similar to that reported in the literature for RT-PCR on fresh or formalin-fixed tissues. The specificity of the assay is very high, being essentially 100% for each primer pair when interpreting the results from visual inspection of agarose gels. However, when these same agarose gels were examined using Southern blotting, a small number of tumors also yielded reproducibly detectable weak signals for unexpected fusion products, in addition to a strong signal for the expected fusion product. Fluorescence in situ hybridization (FISH) studies in one such case indicated that a rearrangement that would account for the unexpected fusion was not present, while another case was equivocal. The overall specificity for each primer pair used in this assay ranged from 94 to 100%. Therefore, RT-PCR using formalin-fixed paraffin-embedded tissue sections can be used to detect chimeric transcripts as a reliable, highly sensitive, and highly specific diagnostic assay. However, we strongly suggest that the final interpretation of the results from this assay be viewed in light of the other features of the case, including clinical history, histology, and immunohistochemistry, by the diagnostic pathologist. Additional studies such as FISH may be useful in clarifying the nature of equivocal or unexpected results.

Blotting, Southern↗

PubMed1995

Molecular and cytogenetic studies in the diagnosis of patients with poorly differentiated carcinomas of unknown primary site.

PURPOSE: A minority of patients with poorly differentiated carcinoma achieve a complete response to cisplatin therapy. Recently, specific chromosomal abnormalities have been described for several solid tumor malignancies. Molecular and cytogenetic techniques were used to study tumors of patients with midline carcinoma of unknown primary site. MATERIALS AND METHODS: Forty patients with poorly differentiated carcinoma of unknown primary site had fresh tumor samples studied by cytogenetic analysis, Southern blot analysis for 12p copy number, and fluorescence in situ hybridization (FISH) for the identification of i(12p) and chromosome 12 aneuploidy. The response to cisplatin therapy was correlated to the diagnosis provided by the genetic studies. RESULTS: In 17 (42%) patients, a diagnosis was suggested by the genetic studies. This included a germ cell tumor in 12 (30%) patients by the finding of i(12p), increased 12p copy number, or a deletion of the long arm of chromosome 12. In five patients, a specific diagnosis other than germ cell tumor was suggested by tumor karyotype. These were neuroepithelioma, lymphoma, desmoplastic small-cell tumor, melanoma, and clear-cell sarcoma. The 75% response proportion to cisplatin therapy in patients with tumors showing chromosome structural abnormalities of germ cell tumor was greater than the 18% response proportion in patients for whom no diagnosis was provided (P = .002). CONCLUSION: Molecular and cytogenetic studies are useful in establishing specific diagnoses in patients with poorly differentiated carcinomas of unknown primary site. This group of tumors is heterogeneous and is composed of germ cell tumors, melanoma, lymphoma, neuroepithelioma, and desmoplastic small-round-cell tumor in addition to some that are not yet classifiable. Response to cisplatin therapy correlates with the finding of i(12p) in tumor by either molecular or cytogenetic studies.

Adenocarcinoma↗

PubMed1987

[A case of Ewing's sarcoma treated successfully by combination chemotherapy consisting of high-dose methotrexate, aclacinomycin-A and vindesine].

A 22-year-old man was admitted to Kyushu University Hospital because of high fever, and pain in the right foot and back. An X-ray examination revealed an osteolytic lesion on the 5th metatarsal bone of the right foot. Paraplegia and disturbance of bladder function occurred and compression of the spinal cord between T3 and L5 was found by myelography. An extradural tumor was removed by emergent laminectomy, and a histological examination of the tumor showed aggregations of small round cells, which suggested Ewing's sarcoma. Although T-9 protocol was started with initial effect, the tumor recurred during the therapy. The patient was then treated with HD-MTX, ACR and VDS, which induced a clinical improvement for 4 months without maintenance therapy. This result showed that HD-MTX, ACR and VDS warrant further consideration for the treatment of refractory Ewing's sarcoma.

Aclarubicin↗

PubMed1992

Expression of pp60c-src in human small cell and non-small cell lung carcinomas.

c-src protein was found in 60% of lung carcinomas (20 of 33 cases or primary tumours) by immunoblotting with a monoclonal antibody (Mab 327) and immunohistochemistry with serum from rabbits bearing tumours induced by Rous sarcoma virus. src protein expression was assessed in 4 small cell lung carcinomas and in an atypical carcinoid of neuroendocrine origin. However, pp60c-src was also found in non-small cell lung carcinomas: in 60-80% of adenocarcinomas and bronchiolo-alveolar cancers and in 50% of squamous cell carcinomas. In the squamous cell carcinomas, src protein was expressed more frequently in poorly differentiated than in well and moderately differentiated carcinomas. Expression of pp60c-src was not found in epithelial cells of histologically unchanged lung tissues. These results show that pp60c-src may be activated in human lung carcinomas of different histopathological types.

Adenocarcinoma↗

PubMed1986

Differentiation between monoclonal antibody-defined antigens on a human osteogenic sarcoma cell line (791T) and tumor-localizing properties of the anti-791T/36 antibody.

Two monoclonal antibodies (anti-791T/36 and anti-791T/48) prepared against an osteogenic sarcoma cell line (791T) following xenogeneic immunization, reacted against the immunizing tumor, but not against normal cells from the tumor-donor, using an indirect 125I-protein A binding assay. Both antibodies cross-reacted with a small number of other osteogenic sarcomas and a few unrelated cell lines from an extensive panel, but the specificity of these cross-reactions was different. Both antibodies were labelled with 125I to detect direct binding to target cells, and the specificity of their reactivity was essentially identical to that observed in the indirect assay. Direct binding of each labelled antibody was inhibited by pretreating target cells with its unlabelled counterpart, but the two antibodies could not inhibit each other. The binding of anti-791T/36 was also not inhibited by pretreating the target cells with sera from the 791-T-tumor donor, which were shown to contain antibody reacting with the autochthonous tumor. It is concluded that 791T has two distinct tumor-associated antigens recognized by the monoclonal antibodies, and furthermore that at least one of these antigens is independent of those recognized by the patient from which the tumor cell line was derived. The efficacy of anti-791T/36 antibody labelled with radioactive iodine was demonstrated for localizing tumor deposits growing in immunodeprived mice.

Animals↗

PubMed1999

[Primary synovial sarcoma of the lung].

In the biopsy material of a polypoid intrabronchial lesion of a 54-year-old male patient with radiologically established lung tumor, spindle-cell neoplasia was seen. No clear histogenetic classification of the submucous tumor process was possible. After resection of the right upper lobe of the lung, including the results of additional immunohistochemical analyses, the tumor was classified as biphasic synovial sarcoma. This was suggested mostly by immunohistochemical detection of the epithelial membrane antigene (EMA) and of vimentin. Extensive clinical examinations ruled out the possibility of a primary tumor with extrapulmonary localization. This case report shows the problems faced in correctly classifying the histogenesis or the direction of differentiation in extremely rare cases of primary pulmonary synovial sarcoma. Especially in small biopsy samples showing a submucous spindle-cell tumor of the lung, apart from frequent sarcoma metastases, the presence of primary synovial sarcoma of the lung has to be considered in the differential diagnosis.

Antigens, CD↗

PubMed1979

Malignant small cell tumor of the thoracopulmonary region in childhood: a distinctive clinicopathologic entity of uncertain histogenesis.

This report describes a unique clinicopathologic entity characterized as a malignant small cell tumor of the thoracopulmonary region in 20 children and adolescents (average age 14.5 years). There was a female predilection (75%) for this tumor which appeared to originate in the soft tissues of the chest wall or the peripheral lung. The neoplasm tended to recur locally and did not seem to disseminate as widely as some of the other small cell tumors of childhood (rhabdomyosarcoma, Ewing's sarcoma, neuroblastoma and malignant lymphoma). However, the median survival was only 8 months. Electron microscopy of 3 cases suggested a neuroepithelial derivation, but, at the present, the histogeneis remains a subject for further investigation.

Adolescent↗

PubMed2002

Cutaneous metastases from Ewing's sarcoma: report of two cases.

Ewing's sarcoma is a malignant osseous neoplasm that affects mostly children and young adult males. Clinically, the neoplasm presents with oedema, swelling, and pain of the involved area. Histopathologically, Ewing's sarcoma consists of solid sheets of small round cells, with vesicular nuclei and scant cytoplasm, arranged in irregular masses separated by strands of fibrous tissue, with areas of necrosis en masse intermingled with intratumoural haemorrhage. Ewing's sarcoma is an extremely aggressive neoplasm and metastases to sites such as lung, pleura, other bones, central nervous system, liver, and regional lymph nodes frequently develop in early stages of the disease. Surprisingly, despite the highly aggressive biological behaviour of this neoplasm, cutaneous metastases from Ewing's sarcoma are very uncommon. We report two patients with Ewing's sarcoma of the bone who developed cutaneous metastases. As in other internal malignancies, the onset of cutaneous metastases in patients with Ewing's sarcoma indicates a poor prognosis.

Adult↗

PubMed1988

Expression of the antigenic determinant recognized by the monoclonal antibody 44-3A6 on select human adenocarcinomas and normal human tissues.

The IgG1 monoclonal antibody, 44-3A6, was raised against the human lung adenocarcinoma cell line, A549. It has been shown to react with a 40,000 MW protein found on the cell surface, which is preserved in formalin-fixed paraffin-embedded tissues. A recent study of pulmonary carcinomas utilizing immunohistochemical methods showed exclusive binding to lung adenocarcinomas, subsets of neuroendocrine tumors, some carcinoids and a subset of large cell carcinomas. Reactivity was not seen in squamous cell carcinomas and small cell neuroendocrine carcinomas. In addition, melanomas, sarcomas and hematologic malignancies do not express this antigen. We now report on the reactivity pattern of 44-3A6 in adenocarcinomas of nonpulmonary primary sites and in normal adults organs. Strong diffuse staining of neoplastic cells in adenocarcinomas of the stomach, colon, pancreas, gallbladder and breast was noted. Adenocarcinomas arising in the endometrium, ovary, kidney, prostate, thyroid and liver were either negative or showed weak and/or focal reactivity. Strong staining patterns were even noted in adenocarcinomas which had an 'undifferentiated' component; i.e., lacking well-defined glandular elements. Immunoreactivity was noted in epithelial cells in several tissues from which these adenocarcinomas arose including the bronchial tract, stomach, small intestine, pancreas and colon, whereas epithelial cells from the endometrium, kidney, ovary, prostate and thyroid were negative or showed diffuse weak immunoreactivity. Our finding indicate that monoclonal antibody 44-3A6 recognizes an epithelial antigen on subsets of normal as well as transformed glandular epithelia. The differential pattern of expression of its target antigen probably reflects differences in tumor genesis and/or differentiation.

Adenocarcinoma↗

PubMed1998

High-dose rate intraoperative radiation therapy for pediatric solid tumors.

BACKGROUND: Sixteen pediatric patients with solid tumors received treatment on a protocol designed to test the feasibility and safety of high-dose rate intraoperative radiation therapy (IOHDR) via a remote afterloader. PATIENTS AND METHODS: Patients with Ewing's sarcoma (n = 5), rhabdomyosarcoma (n = 3), synovial cell sarcoma (n = 2), Wilms tumor (n = 2), osteosarcoma, immature teratoma, desmoplastic small round cell tumor, and inflammatory fibrosclerosis were included. IOHDR was used in the initial management of nine patients and at the time of recurrence in seven. Indications for treatment included gross residual disease in 5 and suspected microscopic disease in 11. The general sites treated were the abdomen (n = 3), chest-wall/thoracic cavity (n = 7), and pelvis (n = 6). All of the patients received multiagent chemotherapy prior to the IOHDR procedure, and 5 had been previously treated with external beam radiation therapy. Separate from the procedure during which IORT was performed, 9 patients underwent an attempt at resection at the time of their initial presentation. A dose of 1200 cGy was prescribed to a depth of 0.5 cm from the surface of a multichannel tissue-equivalent applicator. Complications ascribed to IOHDR included an abscess, delayed wound healing, and cytopenia. Four patients received supplemental external beam radiation therapy to the IOHDR site. At the time of IOHDR, 3 patients had disseminated disease within the pleural cavity and one had pulmonary metastases. RESULTS: With a median follow-up of 18 months, the actuarial rates of local control, metastasis-free, and overall survival at 2 years were 61%, 51%, and 54%, respectively. The patterns of failure were local (n = 1), distant (n = 1), and local + distant (n = 1). Two patients are alive with active disease. Nine are alive with no evidence of disease and the remaining 5 are dead from disease (n = 2), other causes (n = 1), or treatment (n = 2). CONCLUSIONS: The potential to improve local control with high doses of radiation should be balanced against the risk of late effects. The ability to confine the dose of radiation to the primary site and decrease the dose to normal tissues makes IOHDR an important adjunct to external beam radiation therapy. IOHDR can be a safe and integral component in the management of pediatric solid tumors.

Child↗

PubMed1995

Multiplex RT-PCR assay for the differential diagnosis of alveolar rhabdomyosarcoma and Ewing's sarcoma.

Cytogenetic analysis has defined specific translocations associated with two of the most common small round cell tumors of childhood, t(11;22) in Ewing's sarcoma and t(2;13) in alveolar rhabdomyosarcoma. We and others have previously demonstrated the diagnostic utility of a reverse transcriptase polymerase chain reaction (RT-PCR) assay for the detection of the t(11;22) encoded EWS/FLI-1 chimeric message in Ewing's sarcoma. More recently, we have cloned the t(2;13)(q35;q14) translocation and have shown that it results in the fusion of the PAX3 gene on chromosome 2 to FKHR, a novel member of the fork-head family of transcription factors on chromosome 13. To define the morphological spectrum of childhood sarcomas that express the t(2;13) encoded PAX3/FKHR chimeric message, we have performed RT-PCR analysis on samples from 44 primary pediatric sarcomas and 8 sarcoma cell lines. PAX3/FKHR chimeric messages were detected in 24 of 27 alveolar, 2 of 12 embryonal, and 0 of 1 pleomorphic rhabdomyosarcoma and in 1 of 2 ectomesenchymomas. In contrast, none of 8 Ewing's sarcomas or 2 undifferentiated sarcomas expressed this message. Chimeric transcripts were detected in all cases with cytogenetic evidence of the (2;13) translocation, and in each case the chimeric PAX3/FKHR message had the identical junction sequence, suggesting that genomic chromosome breaks were clustered in a single intron in both genes. By combining the PAX3/FKHR RT-PCR assay with primers for detection of the Ewing's sarcoma t(11;22) encoded EWS/FLI-1 chimeric transcript, we have developed a multiplex RT-PCR reaction that allows the rapid and accurate identification of either translocation in a biopsy sample.

Base Sequence↗

PubMed1995

p53 immunostaining in the differentiation of inflammatory pseudotumor from sarcoma involving the lung.

Inflammatory pseudotumor (IPT) of the lung is a non-neoplastic process that consists of proliferating spindle cells (fibroblasts and myoblasts), with variable numbers of mitoses, and inflammatory cells, particularly plasma cells. These lesions clinically, radiographically, and grossly mimic malignant neoplasms but are usually easily distinguished from malignancy on routine histopathology. However, in occasional cases the proliferating spindle cells may histopathologically mimic sarcoma, particularly on small biopsies and needle aspirates. Strong intranuclear immunopositivity for p53 protein is presumed to be indirect evidence of mutation of the p53 tumor suppressor gene and can be detected in many malignancies. In order to determine the utility of p53 immunostaining in differentiating IPT occurring in the lung from sarcoma involving the lung, we immunostained eight solitary IPTs, one IPT that recurred repeatedly over a 10-year period, six sarcomas (two malignant fibrous histiocytomas, two metastatic high-grade sarcomas, one metastatic alveolar soft part sarcoma, and one fibrosarcoma) involving the lung, and one IPT from which a sarcoma arose 10 years after radiation therapy. Immunohistochemistry was performed on 5-microns formalin-fixed sections using a commercially available antibody to the p53 protein (Biogenex, monoclonal 1:200) and a standard antigen retrieval technique. Weak intranuclear staining occurring in less than 10% of proliferating cells was not considered a true immunopositive. All eight of the solitary IPTs were immunonegative for p53 protein by our criteria. The IPT that recurred a number of times and the IPT from which a sarcoma later developed were also immunonegative for p53 protein. Four of the six sarcomas were immunopositive, as was the postradiation sarcoma arising from a p53-immunonegative IPT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Small round cell tumors of the abdomen and thorax. Role of fine needle aspiration cytologic features in the diagnosis and differential diagnosis.

OBJECTIVE: To evaluate the role of cytomorphologic features in the diagnosis and differential diagnosis of small round cell tumor (SRCT) of the abdomen and thorax. STUDY DESIGN: During a period of six years (1985-1990), ultrasound/ computed tomography-guided fine needle aspiration cytology was performed on thoracic and abdominal/ pelvic masses in 899 cases. Slides were not available for review in 28 cases. Review of smears by one of the investigators (D.K.D.) in the remaining cases, which included 239 with intrathoracic and 632 with intraabdominal/pelvic masses, yielded 380 (43.6%) cases of malignancy. Of these, 71 (18.7%) cases were small round cell tumors. In 59 cases of SRCT the smears were found suitable for detailed assessment of cytomorphologic features. RESULTS: The 59 cases of small round cell tumors included 5 cases of neuroblastoma, 7 of hepatoblastoma, 4 of nephroblastoma, 1 of pulmonary blastoma, 2 of Ewing's sarcoma, 23 of non-Hodgkin's lymphoma (NHL), 15 of small cell anaplastic carcinoma (SCAC), 1 NHL/SCAC and 1 small round cell tumor (not otherwise specified). The frequencies of rosettes (60%) and filamentous/fibrillar matrix (100%) in neuroblastoma; acinar formation in hepatoblastoma (100%) and SCAC (93.3%); tubule formation in nephroblastoma (100%); lipid vacuoles (69.6%), exclusive noncohesive cells (95.7%) and lymphoglandular bodies (87%) in NHL; and nuclear molding (100%) and paranuclear blue inclusions (60%) in SCAC were significantly higher as compared to the rest of the SRCTs (P < .01 to < .0001). CONCLUSION: The various cytomorphologic features, alone or in conjunction with other cytologic features, and clinical/imaging findings are very useful in the diagnosis of specific types of SRCT.

Abdominal Neoplasms↗

PubMed1997

Alpha and beta subunits of inhibin/activin as sex cord-stromal differentiation markers.

Inhibins (alpha and beta heterodimers) and activins (beta homodimers) are related peptides with opposing biologic action on gonadotropin regulation. They serve as components of the pituitary-gonadal feedback system. Although sex-cord stromal tumors can usually be distinguished from ovarian epithelial tumors or their metastases by morphology or by using antibodies against intermediate filaments, the diagnosis remains difficult in rare situations in such cases as sarcomatoid granulosa-theca cell tumors, ovarian small cell carcinomas, or soft-tissue sarcomas. A total of 28 sex cord-stromal tumors of the ovary and 43 non-sex cord-stromal tumors were immunohistochemically evaluated for the presence of alpha and beta subunits of inhibin and activin. For comparison, 10 normal adult gonads including seven ovaries with hilar regions and three testes also were examined. Immunoreactivity for both alpha and beta subunits of inhibin/activin was identified in both non-neoplastic and neoplastic granulosa, Sertoli, Leydig, hilar and luteinized theca cells, with the strongest immunoreactivity in Leydig and hilar cells. One of three Sertoli-Leydig cell tumors that showed a sarcomatoid growth pattern and one sex-cord tumor with annular tubules also were immunoreactive for both subunits. For non-sex cord stromal-derived ovarian tumors, alpha subunit immunoreactivity was negative in all but two of five ovarian mucinous tumors. Weak immunoreactivity for beta subunit was found in most ovarian surface epithelial carcinomas, two of four colonic, and one of three pancreatic carcinomas. No immunostaining was found in nonspecialized gonadal stromal or interstitial cells, thecal cells, germ cells, ovarian small cell carcinomas, carcinoid tumors, dysgerminomas, or leiomyosarcomas. Immunostaining of alpha subunit (inhibin alpha), but not of beta subunit could serve as a sex cord-stromal differentiation marker because alpha subunit alone is largely confined to sex cord-stromal lesions with the exception of some ovarian mucinous tumors. Further studies are needed to define the usefulness of this sex cord-stromal differentiation marker in the practice of surgical pathology. Coexpression of alpha and beta subunits in sex cord-stromal elements suggests that dimeric inhibin is expressed in these cells.

Activins↗

PubMed2006

High dose chemotherapy with autologous hematopoietic stem cell support for solid tumors other than breast cancer in adults.

Since the early 1980s high dose chemotherapy with autologous hematopoietic stem cell support was adopted by many oncologists as a potentially curative option for solid tumors, supported by a strong rationale from laboratory studies and apparently convincing results of early phase II studies. As a result, the number and size of randomized trials comparing this approach with conventional chemotherapy initiated (and often abandoned before completion) to prove or disprove its value was largely insufficient. In fact, with the possible exception of breast carcinoma, the benefit of a greater escalation of dose of chemotherapy with stem cell support in solid tumors is still unsettled and many oncologists believe that this approach should cease. In this article, we critically review and comment on the data from studies of high dose chemotherapy so far reported in adult patients with small cell lung cancer, ovarian cancer, germ cell tumors and sarcomas.

Adult↗

PubMed1985

Activity of mitozolomide (NSC 353451), a new imidazotetrazine, against xenografts from human melanomas, sarcomas, and lung and colon carcinomas.

The chemosensitivity of human tumor xenografts to mitozolomide, 8-carbamoyl-3-(2-chloroethyl)imidazo[5-1-d]-1,2,3,5-tetrazin-4(3H) -one, was studied in 3 different assay systems. In concentrations of 1 to 500 micrograms/ml, mitozolomide completely inhibited the colony-forming ability in soft agar of cell suspensions from sarcomas, melanomas, lung and colon cancers, and a mammary carcinoma. When a panel of tumors of the different histological types was tested for its sensitivity to mitozolomide in vitro, in the 6-day subrenal capsule assay in conventional mice, and, in some cases, as s.c. growing tumors in nude mice, good agreement between the different assay systems was seen. In most cases, a very pronounced antitumor effect was observed. The efficacy of mitozolomide was as good or better than that of the drugs clinically used against the tumor types tested. Tumor size measurements and histological examinations indicated that nude mice carrying a melanoma, a small cell lung cancer, and an osteosarcoma were cured of their tumors. The approach here used for evaluating the effect of a new drug on human cancers may be useful for selecting the tumor types which primarily should be studied in clinical trials. The results indicate that clinical responses to mitozolomide may be anticipated in sarcoma, melanoma, small cell lung cancer, and possibly in colon cancer.

Animals↗

PubMed1995

Osteosarcoma and Ewing's sarcoma after neoadjuvant chemotherapy: value of dynamic MR imaging in detecting viable tumor before surgery.

OBJECTIVE: This study analyzed the value of dynamic contrast-enhanced and subtraction MR images in detecting residual viable tumor before surgery, with emphasis on timing of enhancement, in patients with high-grade osteosarcoma and Ewing's sarcoma after neoadjuvant chemotherapy. SUBJECTS AND METHODS: Twenty-one patients with proved osteosarcoma or Ewing's sarcoma were treated with neoadjuvant chemotherapy followed by surgery. After IV administration of gadopentetate dimeglumine, dynamic enhancement patterns on preoperative MR images were compared with corresponding areas on histologic sections of the resected specimens. On dynamic subtraction images obtained with high temporal resolution (1.5-3 sec), the interval between arrival of the bolus of contrast agent in an artery and start of tumoral enhancement was used to distinguish residual viable tumor. Early enhancing foci (interval artery-tumor < 6 sec) and late or nonenhancing areas seen on MR images were correlated with the histopathologic findings in these areas of the resected specimens. RESULTS: Early and progressively enhancing structures seen on MR images corresponded to feeding arteries, physeal vessels, or residual viable tumor at specific preferential sites on corresponding histologic sections of the resected specimens. Tumor foci as small as 3-5 mm2 could be detected on dynamic MR images. Remnant viable tumor was often located subperiosteally and at the margins of the tumor. Occasionally, active periosteal reaction without presence of viable tumor contributed to early enhancement. Late and gradually enhancing or nonenhancing areas corresponded histopathologically to regions of chemotherapy-induced necrosis, mucomyxoid degeneration, or fibrosis. Alternatively, late or nonenhancing areas were associated with reactive changes such as edema, hemorrhage, or osteomyelitis or with tumor-related extracellular matrices such as abundant osteoid or chondroid. Viable tumor areas with scarce formation of matrix on microscopy, such as small cell osteosarcoma areas or Ewing's sarcoma, showed early enhancement with rapid washout of contrast agent on the dynamic MR images. CONCLUSION: Fast dynamic contrast-enhanced sequences are essential for identifying residual tumor before surgery. A short time interval of less than 6 sec between arterial enhancement and tumoral enhancement strongly correlates with presence of viable tumor. Both therapy-related alterations of tissue and tumor-related matrices must be considered when late or lack of enhancement is noted on dynamic MR images.

Adolescent↗

PubMed1982

Small-cell osteosarcoma.

Six cases of small-cell osteosarcoma, a tumor that resembles Ewing's sarcoma but produces osteoid matrix, are presented. The patients were young (6-31 years of age) and presented with symptoms of pain and/or swelling of 1-10 months duration. The lesions demonstrated a wide variation in radiographic appearance. Histologically, the tumors were composed of small, round cells that produced variable amounts of osteoid. In three cases chondroid was also present. Two of the six patients were treated with surgery alone and four received radiation and either single- or multiple-agent adjuvant chemotherapy. The two patients who received radiation and multiple-agent adjuvant chemotherapy have no evidence of disease at four and ten years after diagnosis. Recognition of this tumor as distinct from Ewing's sarcoma and from other forms of osteosarcoma is important to determine the incidence, clinical features, and optimal therapy for this tumor.

Adolescent↗