Stromal inactivation of BMPRII leads to colorectal epithelial overgrowth and polyp formation.

Stromal-epithelial interactions play a central role in development and tumorigenesis. Bone morphogenetic protein (BMP) signaling in the intestine is involved in both of these processes. Inactivation of BMP pathway genes in the epithelium is known to cause intestinal polyposis. However, the role of the intestinal stroma in polyp initiation is incompletely understood. We observed that conditional inactivation of the BMP type II receptor (BMPRII) in the stroma leads to epithelial hyperplasia throughout the colon with increased epithelial cell proliferation. Mutant mice developed rectal bleeding and hamartomatous polyps in the colorectum. The polyps demonstrated increased proliferation of epithelial and mesenchymal cells in the mucosa with an expansion of the myofibroblast cell population. These results demonstrate that genetic mutations altering the BMP signaling pathway in the stromal microenvironment can lead to epithelial tumors in the colon.

Extraskeletal mesenchymal chondrosarcoma: an imaging review of ten new patients.

OBJECTIVE: Extraskeletal mesenchymal chondrosarcoma (EMC) is a rare soft-tissue tumor that most arises in young adults. Because of its rarity, few imaging studies have been reported to date. The purpose of this study was to elucidate the imaging features of this tumor. DESIGN: We conducted a multi-institutional study in cooperation with five referral cancer centers in Japan. Imaging findings of ten new EMC cases, including conventional radiography, computed tomography (CT), and magnetic resonance imaging (MRI), performed at each institute, were reviewed along with clinical features. PATIENTS: Ten patients with EMC, who had been treated at each hospital from 1990 to 2001, participated in this study. RESULTS AND CONCLUSIONS: Soft-tissue masses with well-demarcated, dense and granular calcification were most frequently observed on plain radiographs and CT scans. T2-weighted MR images most clearly depicted a two-component structure composed of calcified and uncalcified areas, and enhanced MRI showed inhomogeneous enhancement in both areas. Although the sensitivity and specificity of these findings are unknown, they might be characteristic and have diagnostic value for this rare tumor.

A practical approach to the clinical diagnosis of Ewing's sarcoma/primitive neuroectodermal tumour and other small round cell tumours sharing EWS rearrangement using new fluorescence in situ hybridisation probes for EWSR1 on formalin fixed, paraffin wax embedded tissue.

BACKGROUND: Over 90% of Ewing's sarcoma/primitive neuroectodermal tumour (ES/PNET) cases have the t(11;22) chromosomal rearrangement, which is also found in other small round cell tumours, including desmoplastic small round cell tumour (DSRCT) and clear cell sarcoma (CCS). Although this rearrangement can be analysed by fluorescence in situ hybridisation (FISH) using routinely formalin fixed, paraffin wax embedded (FFPE) tissues when fresh or frozen tissues are not available, a sensitive and convenient detection method is needed for routine clinical diagnosis. AIMS: To investigate the usefulness of newly developed probes for detecting EWS rearrangement resulting from chromosomal translocations using FISH and FFPE tissue in the clinical diagnosis of ES/PNET, DSRCT, and CCS. METHODS: Sixteen ES/PNETs, six DSRCTs, and six CCSs were studied. Three poorly differentiated synovial sarcomas, three alveolar rhabdomyosarcomas, and three neuroblastomas served as negative controls. Interphase FISH analysis was performed on FFPE tissue sections with a commercially available EWSR1 (22q12) dual colour, breakapart rearrangement probe. RESULTS: One fused signal and one split signal of orange and green, demonstrating rearrangement of the EWS gene, was detected in 14 of 16 ES/PNETs, all six DRSCTs, and five of six CCSs, but not in the negative controls. CONCLUSIONS: Interphase FISH using this newly developed probe is sensitive and specific for detecting the EWS gene on FFPE tissues and is of value in the routine clinical diagnosis of ES/PNET, DSRCT, and CCS.

A malignant peripheral nerve-sheath tumour responding to chemotherapy.

A malignant peripheral nerve-sheath tumour developed in the right S1 nerve root in a man aged 30 causing back pain and sciatica. CT and MRI revealed a destructive tumour of the sacrum invading the retroperitoneal space. The tumour was not resectable with an adequate margin. Chemotherapy, consisting of high-dose ifosfamide followed by a combination of vincristine, doxorubicin and cyclophosphamide, was given with success. Malignant peripheral nerve-sheath tumours are thought to respond weakly to chemotherapy, but the response in our patient was complete.

Low grade malignant peripheral nerve sheath tumour: varied cytological and histological patterns.

BACKGROUND: A small number of malignant peripheral nerve sheath tumours (MPNSTs) are low grade, and the nature of these low grade tumours has never been systematically assessed. AIMS: To describe the clinicopathological, immunohistochemical, and ultrastructural features of low grade MPNST and to discuss the main differential diagnoses. METHODS: Four cases of low grade MPNST were studied, including one coexistent with neurofibromatosis type 1. The tumours were analysed with respect to nuclear atypia, cellularity, nuclear enlargement, hyperchromasia, mitotic rate, and necrosis. Immunohistochemistry was performed by standard techniques, and an ultrastructural study was performed on one tumour. RESULTS: The ages of the patients ranged from 32 to 72 years (mean, 58). Two were male and two were female. Three tumours occurred in the deep tissue, including one in the retroperitoneum, and one was located in the dermal and subcutaneous tissue. The maximum diameters of the tumours ranged from 3.5 to 8.0 cm. Microscopically, all tumours showed moderate hypercellularity, an increased nuclear to cytoplasmic ratio, and hyperchromasia, but exhibited varied growth patterns, including those that were atypical neurofibroma-like, low grade fibromyxoid sarcoma-like, low grade epithelioid, and haemangiopericytoma-like. All tumours showed immunoreactivity for S-100 protein and vimentin. CONCLUSIONS: These findings suggest that careful clinical and histological evaluation, along with S-100 protein immunostaining, are essential for the accurate diagnosis of low grade MPNST.

Prognostic relevance of rosette-like features in osteosarcoma.

AIMS: To clarify the prognostic relevance of rosette-like features and other clinicopathological and immunohistochemical variables in patients with osteosarcoma. METHODS: Clinicopathological and immunohistochemical variables were analysed in 131 patients with non-metastatic high grade conventional osteosarcoma, with particular attention to the prognostic impact of rosette-like features. RESULTS: Rosette-like features were present in 18 (14%) cases. Rosette-like features were significantly associated with the osteoblastic subtype, numerous osteoclast-like giant cells, moderate pleomorphism, frequent haemangiopericytoma-like vascular patterns, epithelioid cytological features, positive immunoreactivity for epithelial membrane antigen and CD56, and negative staining for cytokeratin. In a multivariate analysis, rosette-like features (relative risk (RR), 3.8), a poor chemotherapy effect (RR, 2.9), and a tumour size of 10 cm or more (RR, 2.8) were identified as unfavourable prognostic factors. CONCLUSIONS: Rosette-like features can easily be identified from routine histological slides and the relative risk in patients with non-metastatic, conventional osteosarcoma is as high as other well known prognostic factors, including large size and poor chemotherapy effect.

Osteosarcoma with cytokeratin expression: a clinicopathological study of six cases with an emphasis on differential diagnosis from metastatic cancer.

AIMS: To clarify the clinicopathological profile of osteosarcomas showing an intensely positive immunoreaction for cytokeratin. METHODS: Clinicopathological and immunohistochemical features were analysed in 131 patients with non-metastatic, conventional osteosarcoma, treated in Akita University and National Cancer Centre in Tokyo between 1972 and 1999. RESULTS: Six patients (4.5%; mean age, 32 years; four men, two women) had osteosarcomas showing intense cytokeratin expression. Tumours were located on the long bones of the extremities in five patients and the ilium in one. Osteoid formations were found in biopsied specimens in all cases. Three tumours were classified as osteoblastic osteosarcoma, two as fibroblastic, and one as chondroblastic. In three tumours classified as the osteoblastic subtype, epithelioid features were prominent, and four tumours showed pronounced cellular pleomorphism. In contrast to the expression of cytokeratin, epithelial membrane antigen was negative in all cases. Surgery with a wide excisional margin was performed in six patients. Preoperative and postoperative chemotherapy was given to five of the six patients, but the effects of these agents were negligible. Three of the six patients developed lung metastases, whereas the other three patients have remained well with no evidence of local recurrence or distant metastasis. CONCLUSIONS: Osteosarcoma with intense immunoreaction for cytokeratin was rare. The clinicopathological features were similar to those of patients with conventional osteosarcoma, except for a higher age, chemotherapy resistance, histological epithelioid features, and pleomorphism. This study indicates that osteoid formation and negative expression of epithelial membrane antigen are key features in the differentiation from metastatic carcinoma.

Prognostic significance of grading (MIB-1 system) in patients with myxoid liposarcoma.

AIMS: To determine the relation between clinical outcome and tumour grade defined by a MIB-1 (Ki-67) score based grading system. METHOD: The clinical and pathological features of 50 patients with myxoid liposarcoma were evaluated, and MIB-1 immunostaining was performed to grade these patients' tumours. Univariate and multivariate analyses were conducted to evaluate survival. Clinical follow up details were available for all patients (median, 46.5 months; range, 9-408). RESULTS: Univariate analysis revealed that the tumour site (p < 0.05), round cell component content (p < 0.01), necrosis (p < 0.01), mitosis (p < 0.01), MIB-1 labelling index (p < 0.001), and tumour grade (p < 0.001) had a significant impact on overall survival. Multivariate analysis showed that, of the variables evaluated, the tumour grade defined by a MIB-1 score based grading system was the most significant adverse prognostic factor. CONCLUSION: Tumour grade determined by the grading system using the MIB-1 score (MIB-1 system) is a very strong prognostic factor in patients with myxoid liposarcoma.

Germline p53 mutation in a patient with multiple primary cancers.

We report a case of multiple primary cancers having a germline missense mutation of the p53 gene. The patient was a Japanese female and had a history of five different types of cancers. PCR/direct sequencing analysis revealed the presence of a nucleotide substitution, AGC (Ser) to AGG (Arg), at codon 106 of the p53 gene in DNA from non-cancerous breast tissue. This is the first case of germline p53 mutation at codon 106, and could contribute to establishing correlations between the types and locations of germline p53 mutations and their phenotypical consequences.

Absence of germline CHK2 mutations in familial gastric cancer.

Recently, the CHK2 gene was identified as being a candidate gene responsible for Li-Fraumeni syndrome (LFS). Gastric cancer is often clustered in families with LFS, so it is possible that germline CHK2 mutation is also present in familial gastric cancer (FGC). We therefore defined the genomic structure of the CHK2 gene, designed intronic primers, and searched for germline CHK2 mutations in 25 FGC cases by polymerase chain reaction-single strand conformational polymorphism analysis of the entire coding region. In all of the 25 cases, at least two siblings had histories of gastric cancer. There were no FGC cases that showed germline CHK2 mutations. Thus, it was indicated that germline CHK2 mutations do not contribute to the familial clustering of gastric cancer.

Prognostic relevance of a histological grading system using MIB-1 for adult soft-tissue sarcoma.

Several histological grading systems have been proposed and found as strong indicators of outcome in soft-tissue sarcomas. However, a putative independent prognostic influence of recently developed biological and molecular markers remains to be established. This study investigated the prognostic relevance of a histological grading system based on the assessment of proliferative activity in adult soft-tissue sarcomas of the extremities, trunk, head, and neck. Tissue blocks from 95 of 108 patients without distant metastases or regional lymph node involvement were available. Immunohistochemical staining for MIB-1 and p53 was done on paraffin-embedded sections. All clinicopathologic and immunohistochemical variables and patient survival were assessed using univariate and multivariate analyses. Variables included histological grading based on the modified Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) system using the MIB-1 score for the estimation of the proliferative potential of the tumors. Variables associated with overall survival were tumor site in the trunk, head and neck, mitosis count, necrosis, MIB-1 score, FNCLCC grade, modified FNCLCC grade using the MIB-1 score, and stage (all p values <0.05). In multivariate analysis, the modified grade proved to be the most significant predictor of shortened overall survival, in addition to tumor site in the trunk, head, and neck. Overexpression of p53 did not correlate with increased risk of tumor mortality. Using MIB-1 to replace mitosis counts in the FNCLCC system improves grading of soft-tissue sarcomas, and this in conjunction with other important factors appear to be more accurate prognostic factors for survival, and for patient selection in investigational adjuvant treatment trials.

A multidisciplinary approach to the treatment of malignant pelvic bone tumors: results with eight consecutive patients.

The prognosis for malignant pelvic bone tumors is worse than that for malignant bone tumors of the extremities because definitive surgery in the pelvis is often difficult to accomplish. The results for eight patients who were treated consecutively with a multidisciplinary approach, from 1990, were analyzed. The histologic diagnosis was osteosarcoma in five patients, chondrosarcoma in two, and Ewing's sarcoma in one. Five lesions arose in the ilium and three in the pubis. The extraosseous tumors decreased in size and/or were encapsulated as a result of preoperative chemotherapy in six patients, four of these achieving a wide surgical margin. With respect to tumor location and surgical margin, all five lesions in the ilium involved the sacrum, four of these being resected with an inadequate margin. The three lesions in the pubis were resected with an adequate margin. Local recurrence was observed in two patients who had been treated with an inappropriate margin. During the period between 18 and 57 months after the first operation, five patients were continuously free of disease and one was still alive but had lung metastases. Our results indicate that a patient's chances of definitive surgery may be enhanced by a multidisciplinary approach, although the management of sacroiliac involvement remains challenging.

Synovial sarcoma, histologically mimicking primitive neuroectodermal tumor/Ewing's sarcoma at distant sites.

We report a case of synovial sarcoma (SS) showing unusual histology at distant sites. A 47-year-old man was aware of a tumor on the sole of his left foot. After preoperative chemotherapy with a diagnosis of SS, wide excision was performed. During postoperative chemotherapy, multiple tumorous lesions developed in the bone (including the whole spine) and both lungs. The patient died 1 year later. Histologically, the excised tumor of the foot showed a biphasic cellular pattern typical of SS, whereas at autopsy the bone and lung lesions were composed only of undifferentiated small round cells with cytoplasmic fibrillar processes. Homer-Wright rosettes were also observed. Immunohistochemically, 80% of the bone and lung tumor cells expressed MIC2 protein homogeneously. To clarify whether the bone and lung round cell tumors were metastatic lesions or second malignancies, especially primary primitive neuroectodermal tumor (PNET)/Ewing's sarcoma (ES), we performed reverse transcription-polymerase chain reaction (RT-PCR) analysis of tumor type-specific fusion gene transcripts. The SYT/SSX fusion transcript was identified in both the foot and lung lesions, whereas the EWS/FLI1 transcript was not detected in either lesion. Therefore, we concluded that the multiple bone and lung tumors were poorly differentiated metastatic tumors, which arose from the SS of the foot. We also conclude that the identification of chimeric fusion transcripts can be successfully applied to poorly differentiated sarcomas and will help in the differential diagnosis of tumors that cannot be distinguished by conventional morphological examinations. Also, it should be remembered that cytoplasmic staining for MIC2 protein may occur in sarcomas other than PNET/ES.

Color tuning mechanism of human red and green visual pigments.

We investigated the molecular mechanism of a rather large red shift of 31 nm in a human red pigment compared with a human green pigment. In this analysis, we paid special attention to the phenomenon of nonadditivity of spectral shifts due to substitution of the key amino acids (OH-bearing amino acids) and the phenomenon of cooperativity by which the spectral shifts due to substitution of the key amino acids in the protein environment of red pigment are about 1.5 times larger than that in the protein environment of green pigment. The analysis was made by using a model of three active sites on which the key amino acids are located and four effective sites by which the effect of the key amino acids is modified. As a result, we found that the interaction between the active sites that occurs through the repolarization of the chromophore induced by the key amino acid is essential for the nonadditivity phenomenon. We also found that the interaction between the active site and the effective site plays a major role in the cooperativity phenomenon. More directly, we say that the highly polarizable property of the chromophore is the origin of the rather large red shift in red pigment. Based on these analyses, we conclude that the interaction between the polarizable chromophore and the protein moiety has the capability of producing a significant spectral shift, at least 1000 cm-1, even by substitution of moderate polar residues of the OH-bearing amino acids.

Pulmonary artery sarcoma diagnosed using intravascular ultrasound images.

Primary and secondary malignant intravascular tumours of the pulmonary artery occur infrequently and the diagnosis is usually delayed as symptoms and findings from conventional examinations are non-specific. The case is presented of a patient with a pulmonary artery sarcoma, probably arising from ribs resected some years previously, in which intravascular ultrasound (IVUS) provided important diagnostic findings.

The human mucus protease inhibitor and its mutants are novel defensive compounds against infection with influenza A and Sendai viruses.

Tryptase Clara, a trypsin-like protease localized exclusively in and secreted by Clara cells of the bronchial epithelium, is a prime host factor that processes viral envelope glycoproteins and determines the infectivity of influenza A and Sendai viruses (H. Kido, Y. Yokogoshi, K. Sakai, M. Tashiro, Y. Kishino, A. Fukutomi, and N. Katunuma, The Journal of Biological Chemistry, 1992, Vol. 267, pp. 13573-13579). We report here that human mucus protease inhibitor (MPI), a major inhibitor of granulocyte elastase in the lining fluid of the human respiratory tract, significantly inhibited induction of the infectivity of influenza A and Sendai viruses by tryptase Clara in vitro and multicycles of mouse-adapted influenza A virus replication in rat lungs in vivo. Recombinant MPI and the C- but not the N-terminal domain of MPI inhibited both the activity of tryptase Clara and the induction of virus infection by tryptase Clara. The 50% inhibitory concentrations of MPI and the C-terminal domain peptide (Pro50-Ala107) of MPI for tryptase Clara were 7.4 and 61.6 nM, respectively, with Sendai virus envelope glycoproteins as the substrate. Studies on deletion mutants of the C-terminal domain of MPI revealed that the minimal size of MPI required for the inhibition of tryptase Clara is the peptide Lys60-Ala107. Studies involving site-directed mutagenesis of the C-terminal domain of MPI indicated that the Leu72-Met73 site of MPI is the inhibitory site for tryptase Clara. Substitution of residue Leu72 with a basic amino acid significantly increased in the inhibitory activity of the C-terminal domain of MPI, but further substitution of residue Met73 with various amino acids in these mutants reduced the inhibitory activity. Since there is evidence suggesting that the concentration of MPI in respiratory fluid is insufficient for prevention of virus infection, the administration of MPI, the recombinant C-terminal domain of MPI, and their mutants, with residue Leu72 substituted with residues Arg72 and Lys72, may be useful for treatment of such pneumotropic virus infections.

Intracortical osteoblastic osteosarcoma with oncogenic rickets.

Intracortical osteosarcoma is the rarest variant of osteosarcoma, occurring within, and usually confined to, the cortical bone. Oncogenic osteomalacia, or rickets, is an unusual clinicopathologic entity in which vitamin D-resistant osteomalacia, or rickets, occurs in association with some tumors of soft tissue or bone. We present a case of oncogenic rickets associated with intracortical osteosarcoma of the tibia in a 9-year-old boy, whose roentgenographic abnormalities of rickets disappeared and pertinent laboratory data except for serum alkaline phosphatase became normal after surgical resection of the tumor. Histologically, the tumor was an osteosarcoma with a prominent osteoblastic pattern. An unusual microscopic feature was the presence of matrix mineralization showing rounded calcified structures (calcified spherules). Benign osteoblastic tumors, such as osteoid osteoma and osteoblastoma, must be considered in the differential diagnosis because of the relatively low cellular atypia and mitotic activity of this tumor. The infiltrating pattern with destruction or engulfment of normal bone is a major clue to the correct diagnosis of intracortical osteosarcoma. The co-existing radiographic changes of rickets were due to the intracortical osteosarcoma.

Ganglion cells in Ewing's sarcoma following chemotherapy: a case report.

A case of Ewing's sarcoma of the bone, arising in the right radius of a 12-year-old girl, which showed unique histologic features after pre-operative treatment, is reported. The light microscopic features of a biopsy sample were those of a small round cell tumor showing positive immunoreaction with antibodies against the product of the MIC 2 gene (O13), neuron-specific enolase, neurofilament, and synaptophysin, but no morphological differentiation. The patient received combined intensive multi-drug chemotherapy and radiation before surgery. Examination of the surgical specimen showed that the tumor was less cellular than that in the biopsy specimen, and was composed mainly of loosely textured large cells mimicking ganglion cells, occasionally forming Homer-Wright rosettes. An immunohistochemical study revealed that neural differentiation was enhanced. Immunoreactivity for Leu-7 also became positive. Although the patient underwent postoperative chemotherapy, she died of multiple lung and bone metastases 30 months after the diagnosis. Autopsy showed that metastatic foci were made up of densely packed small round cells like those seen in the biopsy samples, but associated with prominent Homer-Wright rosettes. To the authors' knowledge, this is the first report of a tumor being replaced almost entirely by ganglion cells after pre-operative chemotherapy and radiotherapy.

[TNM classification of bone and soft tissue sarcomas].

TNM classification of bone and soft tissue sarcomas was published by UICC in 1987. Histological grading (G) is an important factor in this classification, but the criteria of G categories are not so clear. In addition, lymph node metastasis is very rare in bone and soft tissue sarcoma. Therefore, prognostic factors are limited to T, M and G categories. Since correlation between the stage (UICC) and the survival rate was not found in patients with osteosarcoma, TNM classification (UICC) has not been used widely in the field of orthopedic oncology. The Musculoskeletal Tumor Committee of the Japanese Orthopaedic Association proposed another TNM classification of osteosarcoma based on multivariate analysis. T1 is less than 15 cm and T2 is 15 cm or larger in maximal diameter. N and M are same with the UICC criteria. Serum alkaline phosphatase level (A) is included in this classification in which A0 is less than the normal value x2.5, and A1 is the normal value x2.5 or more. G categories are separated into two groups according to the mitotic rate in a high power field (x200); G1 is assigned to the tumor with 0-9/1 HPF and G2 is assigned to those with 10 or more/1 HPF. Reclassification of osteosar-coma by this modified TNM system indicated that there was a correlation between the survival rate and the stage.

[Improvement in function-preservation in radiotherapy for pediatric malignancies].

In radiotherapeutic management for pediatric tumors, we have to pay more attention to confinement of higher dose to the target volume than for adult tumors, in order that the risk of untoward normal tissue complications dose not increase, such as growth retardation. Two current approaches performing in our department to match this purpose are presented, namely, perioperative brachytherapy and fractionated stereotactic radiotherapy (F-SRT). In perioperative brachytherapy for bone and soft tissue sarcoma, plastic guide tubes for introducing radioactive sources are placed in the residual tumor bed or at the margins during the surgery, and patients are treated by high-dose-rate brachytherapy after surgery. Patients are not restricted in radioprotective area, and the overall treatment period is short enough. F-SRT is used either as the boost of conventional brain radiotherapy in primary brain neoplasms, or as hypofractionated F-SRT for control of metastatic brain tumors, with nearly perfect local control and maintenance of good quality of life. F-SRT is planned in 3-dimensional fashion from computed tomography images. Easily detachable, relocatable cast made for F-SRT is useful in pediatric patients.