Synthesis and biological activity of folic acid and methotrexate analogues containing L-threo-(2S,4S)-4-fluoroglutamic acid and DL-3,3-difluoroglutamic acid

Clinical and pathological features of 52 infants and children with atypical teratoid/rhabdoid tumor (ATT/RhT) of the central nervous system are defined. This tumor is typically misdiagnosed as a primitive neuroectodermal tumor (PNET) primarily because 70% of ATT/RhTs contain fields indistinguishable from classic PNETs. Separation of these two tumor types is crucial because the prognosis for ATT/RhT is given even when treatment includes surgery with or without radio and/or chemotherapy. These tumors are most common in infants less than 2 years of age. The cases described in this study arose in intracranially in all but one instance, although one-third had already spread throughout the subarachnoid space at presentation. Clinical signs and symptoms and radiological features do not distinguish ATT/RhTs from PNETs. The tumors are composed entirely (13%) or partly (77%) or rhabdoid cells. Seventy percent contains fields of typical PNET alone or in combinations with mesenchymal and/r epithelial elements. The immunohistochemical profile is unique: epithelial membrane antigen, vimentin, and smooth-muscle actin are positive in the majority of tumors and markers for germ-cell tumors are consistently negative. Abnormalities of chromosome 22 distinguish ATT/RhTs from PNETs, which typically display an i(17q) abnormality.     

"Proximal-type" epithelioid sarcoma, a distinctive aggressive neoplasm showing rhabdoid features. Clinicopathologic, immunohistochemical, and ultrastructural study of a series

Eighteen examples of an unusual malignant soft-tissue neoplasm, the morphology of which ranged from that of "atypical" epithelioid sarcoma to that of a rhabdoid tumor or undifferentiated carcinoma (with transitional forms) are described. Patients included 11 males and seven females; their median age was 35.5 years with most patients aged 20 to 40 years. Development of a mass was the main presenting symptom. Six tumors developed in the pelvis and perineal region, four in the pubic region and vulva, three in the buttocks, one in the deep soft tissues of the left hip, one on the penis, one in left forearm, one in left axilla, and one on the occiput. Tumor size ranged from 1 to 20 cm (median, 4 cm). On microscopic examination, the tumor cells invaded the subcutaneous or deep soft tissues, had prominent epithelioid or rhabdoid features, had marked cytologic atypia, and grew in a multinodular pattern in half of the cases. Areas of necrosis were often seen. A granuloma-like pattern reminiscent of that observed in classic epithelioid sarcoma was observed in only two cases. Immunohistochemically, positivity for cytokeratin, epithelial membrane antigen, and vimentin was seen in all but one of the cases. Of 16 cases, 10 and eight tumors reacted with desmin and CD34, respectively; five of 15 reacted at least focally with smooth-muscle actin, whereas three of 13 and one of 10 reacted for HMB-45 and carcinoembryonic antigen, respectively. S-100 protein and CD31 yielded negative results. Seven tumors were investigated at the ultrastructural level, four of which showed prominent intracytoplasmic intermediate filament aggregates, often accumulating into paranuclear whorls, which is in keeping with the rhabdoid phenotype. Five tumors showed features of epithelial differentiation (i.e., tonofilament-like structures or desmosomes or both), whereas one tumor displayed features of myofibroblastic differentiation. Differential diagnoses include mainly conventional epithelioid sarcoma, extrarenal malignant rhabdoid tumor, epithelioid malignant peripheral nerve sheath tumor, melanoma, rhabdomyosarcoma, and undifferentiated carcinoma. Follow-up information on 14 patients (range, 4 months to 8 years; median, 19 months) revealed local recurrence in one case and metastatic dissemination in six patients, leading to death in five. In our opinion, the above-described neoplasms represent a usually "proximal-type" of epithelioid sarcoma. In contrast to the conventional, "distal-type" epithelioid sarcoma, the proximal variant is characterized by a predominantly large-cell, epithelioid cytomorphology, marked cytologic atypia, frequent occurrence of rhabdoid features, and lack of a granuloma-like pattern in most cases. It appears to be somewhat more aggressive (or at least metastasizes earlier) than usual epithelioid sarcoma.     

Role of electron microscopy in the evaluation of soft tissue neoplasms, with emphasis on spindle cell and pleomorphic tumors

The current significant role of transmission electron microscopy in the evaluation of soft tissue tumors when correlated with conventional histological and immunohistochemical studies is discussed for the following entities: myxofibrosarcoma, storiform-pleomorphic fibrosarcoma (malignant fibrous histiocytoma), and myofibrosarcoma; dermatofibrosarcoma protuberans; hemangiopericytoma; monophasic synovial sarcoma; extrarenal rhabdoid tumor; soft tissue perineurioma; and gastrointestinal stromal tumors, notably the so-called autonomic nerve variant.     

Genetic testings for cancer: the surgeon's critical role. Familial colon cancer

We examined 18 atypical teratoid and rhabdoid tumors of the brain and 7 renal and 4 extrarenal rhabdoid tumors for mutations in the candidate rhabdoid tumor suppressor gene, INI1. Fifteen tumors had homozygous deletions of one or more exons of the INI1 gene, and the other 14 tumors demonstrated mutations. Germ-line mutations of INI1 were identified in four children, one with an atypical teratoid tumor of the brain and three with renal rhabdoid tumors. These studies suggest that INI1 is a tumor suppressor gene involved in rhabdoid tumors of the brain, kidney, and other extrarenal sites.     

Exposure to high ambient temperature increases absorption and plasma concentrations of transdermal nicotine

Granulosa cell tumors with bizarre nuclei (GCT-BN) are rare lesions with a prognosis apparently similar to that of conventional granulosa cell tumors (GCT-NOS). The immunohistochemical features of GCT-BN have not been described, and the exact nature of the bizarre nuclei (BN) is unclear. Thirteen GCT-BN were studied with antibodies to cytokeratin, vimentin, epithelial membrane antigen, muscle-specific actin, alpha smooth muscle actin, desmin, and S-100 protein. Six cases were also examined by fluorescence in situ hybridization for trisomy 12, a nonrandom chromosomal aberration found in a proportion of ovarian sex-cord stromal tumors. Histologically, 12 tumors (86%) contained BN areas interspersed with large areas of GCT-NOS. The remaining tumor contained only microscopic foci of GCT-NOS. Immunohistochemically, the tumors stained for vimentin (13 tumors), S-100 protein (11 tumors), muscle-specific actin (10 tumors), cytokeratin (eight tumors), alpha smooth muscle actin (eight tumors), and desmin (one tumor), but none stained for epithelial membrane antigen. Immunostaining results for the BN and GCT-NOS areas were concordant in eight (73%) of the 11 tumors in which both areas could be independently assessed. The remaining three tumors (27%) showed discordant results for only one of the eight markers used. In five patients, trisomy 12 was detected by fluorescence in situ hybridization in areas of BN but not in areas of GCT-NOS present in the same tumor. Trisomy 12 was also present in another BN tumor in which the foci of GCT-NOS were too small to be evaluated. We conclude that within GCT-BN, areas with BN are immunohistochemically similar to areas of GCT-NOS present in the same tumor. The finding of trisomy 12 in areas with BN but not GCT-NOS in the same tumor, however, suggests that cells with BN represent a genetically distinct clone of tumor cells arising within GCT-NOS.     

Primitive neuroectodermal tumors of bone and soft tissue: histological subclassification and clinicopathologic correlations

Recent reports of Ewing's sarcoma (EW) and extraskeletal Ewing's sarcoma (EEW) support the hypothesis that these tumors are neuroectodermal in origin. Primitive neuroectodermal tumors (PNET) of bone (32 cases) and soft tissue (25 cases) including those previously categorized as EW in 27 cases and EEW in 15 cases were carefully studied histologically, immunocytochemically and morphometrically, focusing on tumor cell differentiation. This study attempts to subclassify these tumors on the basis of the size of tumor cells and nuclei, their variations (uniformity or diversity), arrangement of tumor cells (rosette or non-rosette), focal differentiation to larger ganglion-like cells, and staining intensity for neural markers. All tumors were histologically subclassified as small, medium or large cell types, three basic subtypes (rosette type, abortive rosette type, non-rosette type) and four complementary subtypes (fibrillary type, non-fibrillary type, angiomatoid type, ganglion cell type). Classic EW or EEW is consistent with small or medium, non-rosette, non-fibrillary type tumors, previously described large cell EW with large, non-rosette, fibrillary or non-fibrillary type tumors, and classic neuroectodermal tumor with small or medium, rosette, fibrillary type tumors, according to the present subclassification. Clinicopathologic correlations with the different subtypes are discussed. Long-term survival, more than 5 years, was seen in patients with small cell type, and those younger than 14 years of age.     

"Rhabdoid" meningioma: an aggressive variant

It is has been suggested that rhabdoid morphology is associated with a poor prognosis, regardless of tumor histogenesis. We report a series of 15 meningiomas with rhabdoid features. Nine patients had undergone multiple resections. In six, the rhabdoid component was histologically apparent only in recurrences. Rhabdoid morphology was defined as sheets of loosely cohesive cells with eccentric nuclei and hyaline, paranuclear inclusions. Ultrastructurally, the latter consisted of whorls of intermediate filaments often entrapping lysosomes or other organelles. Meningothelial features included whorl formation and nuclear pseudoinclusions, immunohistochemical coexpression of vimentin and epithelial membrane antigen, and the ultrastructural finding of interdigitating cell membranes and intercellular junctions. At the histologic level, a conventional meningioma component was noted in most tumors; only four lesions were entirely rhabdoid. Histologic malignancy (brain invasion or anaplasia) was observed in nine cases, another two tumors being considered malignant on the basis of extracranial metastasis. In the majority, increased cell proliferation was evidenced by a high mitotic rate or MIB-1 LI. At last follow-up, 13 patients (87%) had experienced at least one recurrence and 8 (53%) were dead of disease. Median time to death was 5.8 years after initial surgery and 3.1 years after the first appearance of rhabdoid morphology. Our findings corroborate those from a smaller series recently reported by Kepes et al. on the same entity (Kepes JJ, Moral LA, Wilkinson SB, Abdullah A, Llena JF. Rhabdoid transformation of tumor cells in meningiomas: A histologic indication of increased proliferative activity. Report of four cases. Am J Surg Pathol 1998;22:231-8). They further suggest that rhabdoid meningiomas are highly aggressive tumors and that the rhabdoid phenotype represents a marker of malignant transformation in meningiomas.     

Poorly differentiated synovial sarcoma: immunohistochemical distinction from primitive neuroectodermal tumors and high-grade malignant peripheral nerve sheath tumors

Synovial sarcoma is a relatively common sarcoma in adults, which in its classic bimorphic form infrequently poses a diagnostic problem. Monomorphic spindled variants, as well as the less common poorly differentiated variants, may be confused with other soft-tissue sarcomas; the poorly differentiated variant (PDSS), in particular, may be histologically indistinguishable from other small, blue, round cell tumors, including primitive neuroectodermal tumors (PNETs). Detection of the synovial sarcoma-associated t(X;18) by either cytogenetic or molecular genetic approaches may be necessary to confirm the diagnosis of synovial sarcoma in difficult cases. We evaluated 10 cases of PDSS from eight patients using a panel of antibodies (including those to intermediate filament proteins, nerve-sheath associated markers, and neuronal and neuroectodermal associated markers) in order to better establish the immunophenotype of this tumor and to help distinguish it from the tumors with which it may be confused, particularly PNETs and high-grade malignant peripheral nerve sheath tumors (MPNSTs). Our results showed PDSS to have significant immunophenotypic overlap with both PNETs and MPNSTs. In most instances these three entities may be differentiated by a panel of antibodies that should include those to both low and high molecular weight cytokeratins, epithelial membrane antigen, type IV collagen, CD99, CD56, and S-100 protein. Our results also suggest that synovial sarcoma may be a tumor showing combined neuroectodermal and nerve sheath differentiation--perhaps because of translocation-associated expression of specific proteins--rather than a carcinosarcoma of soft tissues or a tumor of specialized arthrogenous mesenchyme.     

Soft tissue small round cell tumors: morphological parameters

Soft tissue small round cell tumors (SRCTs) comprise a heterogeneous group of neoplasms that predominate in childhood and adolescence and share similar morphological features, consisting of dense cellular proliferation of small round cells with a primitive appearance. Rhabdomyosarcomas, peripheral neuroepitheliomas, Ewing's sarcomas, and lymphomas/leukemias are the prototypic SRCT; other recently described tumors that should be added to the list are the desmoplastic SRCT and the rhabdoid tumor of soft tissues. In addition, several other primary soft tissue neoplasms and metastatic tumors have occasionally been considered in the differential diagnosis of SRCT. The precise identification of a given SRCT is important because of its clinical relevance. However, it may be difficult because the diagnostic criteria are sometimes subtle and several histologic and immunohistochemical features are not specific and/or may be simulated by different tumor types. We discuss the morphological clues that in our opinion are most useful for their diagnosis, the criteria for distinguishing between peripheral neuroepithelioma and Ewing's sarcoma, and the main diagnostic pitfalls.     

Secretory meningioma: clinical, histologic, and immunohistochemical findings in 31 cases

BACKGROUND: Secretory meningioma is a rare histologic variant characterized by a unique epithelial differentiation of meningothelial cells resulting in the production of hyaline inclusions. Most previous reports have presented single case observations. The authors selected 31 cases for a clinicopathologic study to characterize this type of tumor further. METHODS: Clinical data were compiled and the extent of peritumoral edema was assessed from preoperative computed tomography or magnetic resonance imaging scans. Preparations of surgical specimens of all tumors were studied after both conventional histologic and immunohistochemical preparations were made. Immunostaining was performed by either the avidin-biotin complex method or the alkaline phosphatase-antialkaline phosphatase method using 22 primary antibodies. RESULTS: In the tumor collection used in this study, secretory meningiomas represented 3% of meningiomas. The female-to-male ratio was 9:1. Most tumors were located at the sphenoid ridge or at the frontal convexity, and recurrences were not observed. Eighty-four percent of tumors presented with slight to marked peritumoral edema. The MIB-1 staining index showed a mean of 3.8%. Inclusions and surrounding cells consistently expressed epithelial membrane antigen, cytokeratins, carcinoembryonic antigen, and carbohydrate antigen 19-9. In decreasing frequency, they also contained alpha1-antitrypsin, immunoglobulin (Ig)A, alpha1-antichymotrypsin, IgM, and IgG. Cells positive for vimentin and S-100 did not contain inclusions. All tumors were positive for progesterone receptors. Macrophages were stained with antibodies to factor XIIIa, human leukocyte antigen-DR, and alpha1-antitrypsin. In 64% of cases, tumor vessels lacked expression of glucose transporter protein 1. CONCLUSIONS: The classification of secretory meningioma as a distinct variant has been justified on clinical, histologic, and immunohistochemical grounds. The unique epithelial features call attention to the broad spectrum of differentiation properties found in meningiomas.     

March 1997--4 year old girl with ring chromosome 22 and brain tumor

A four year old Caucasian girl with a constitutional ring chromosome 22 abnormality and developmental delay presented with increasing ataxia and a six week history of non-specific symptoms. Imaging studies demonstrated a large third ventricular tumor with apparent involvement of the septum. Microscopic and immunohistochemical studies demonstrated an atypical teratoid/rhabdoid tumor. This tumor is compared and contrasted to peripheral malignant rhabdoid tumors and central primitive neuroectodermal tumors. The role of a putative tumor suppressor gene on the long arm of chromosome 22 in the pathogenesis of these tumors is also discussed.     

Eutocic delivery

BACKGROUND AND METHODS: Because the use of immunohistochemistry in the diagnosis of granulosa cell tumor (GCT) has not been fully explored, routinely processed (formalin-fixed, paraffin-embedded) tissue from 11 GCT, adult type, was investigated immunohistochemically (ABC method) with a broad spectrum of antibodies against various markers, including p53 and Ki-67. All of the tumors exhibited typical morphology, were limited to the ovary (stage I), and 7 cases followed a benign clinical course. RESULTS: All the tumors exhibited strong expression of vimentin, but most other antigens (including smooth muscle actin) were expressed infrequently by a minority of tumor cells or not at all. Tumor cells in 9 GCT expressed inhibin A. All the tumors exhibited very low proliferative activity, fewer than 10% of the tumor cell nuclei being stained by the antibody MIB-1 (Ki-67 antigen). The antibody D07 revealed marked overexpression of p53 protein in only one tumor. Clinical outcome was not found to be related to immunophenotypic differences. CONCLUSIONS: The diagnosis of GCT should be based primarily on the typical morphology revealed by conventional stains, but additional immunohistochemical staining with a small panel of selected antibodies (for example, against keratin, vimentin, and inhibin A) may be helpful in a few cases. The very low proliferative activity and the lack of overexpression of p53 protein are consistent with the benign clinical behavior of the majority of GCT.     

Conformational study of a collagen peptide by 1H NMR spectroscopy: observation of the 14N-1H spin-spin coupling of the Arg guanidinium moiety in the triple-helix structure

A 36-month-old girl had a 3-week history of proptosis of the right eye. Computed tomography showed an ill-defined homogeneous mass filling the intraconal space. Histopathologic examination and immunohistochemistry findings of an incisional biopsy specimen were consistent with malignant undifferentiated tumor with rhabdoid features. Despite chemotherapy (a combination of vincristine sulfate and dactinomycin) and radiotherapy, massive orbital recurrence occurred 6 months later and orbital exenteration was performed. The recurrent tumor was composed entirely of pleomorphic epithelial cells with prominent nucleoli and many filamentous cytoplasmic inclusions. Immunohistochemical staining showed positive immunoreactivity for vimentin, cytokeratin, and epithelial membrane antigen, and negative immunoreactivity for muscle-specific antigen, melanoma, neural, and histiocytic markers. Electron microscopy excluded myogenic differentiation and showed that the filamentous cytoplasmic inclusions were composed of whorls of intermediate filaments. Aggressive chemotherapy with a combination of vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide phosphate was continued after exenteration. At 17 months' follow-up, orbital debulking surgery with externalization of the maxillary sinus was performed because of massive tumor recurrence in the right orbit and growth into the maxillary sinus. The child died 23 months after initial diagnosis from tumor invasion into the central nervous system. Extrarenal rhabdoid tumor is a rare orbital mass that carries a poor prognosis.     

Intermediate filaments

The antibodies for intermediate filaments, including keratin, vimentin, desmin, GFAP and neurofilaments, have been much useful in routinely-processed immunohistochemical study for identifying characteristics of tumor cells or making the definite diagnosis. In general, when neoplastic transformation has taken place, the affected cells would reveal to some extent alterated immunolocalization of intermediate filaments in the cytoplasm. Whether the tumor cells are of epithelial or non-epithelial origin is significant from diagnostic points of view when utilizing those intermediate filaments as tumor markers. But there are many "exceptional" cases of epithelial tumors with expression of vimentin, or those of non-epithelial tumors with expression of keratin, indicating some "variants". Immunohistochemical application of the intermediate filaments is indispensable not only as "a diagnostic tool for surgical pathologists", but also a method for analyzing relationship between morphological changes and functional aspects of the tumor cells.     

The clinical role of molecular genetics in soft tissue tumor pathology

Cytogenetic and molecular analysis of soft tissue tumors has yielded a wealth of information over the past decade. Some of the genetic aberrations that have been identified appear to be fairly specific for individual tumor types. It is because of this specificity that these findings harbor the promise to become useful as diagnostic and/or prognostic markers. Technical advances that allow the application of cytogenetic and molecular techniques to archival material have been crucial in this respect. Molecular genetics has already become an integral part of the work-up of some tumors, e.g., small cell sarcomas of childhood, which demonstrate fairly characteristic translocations, often involving the Ewing's sarcoma gene. Some genetic abnormalities have become established as prognostic markers, such as the deletion of the short arm of chromosome 1 for neuroblastomas. Soft tissue tumor pathology has also benefitted from major advances in identifying genes that are critical in mesenchymal differentiation or cell cycle control. MyoD is a good example of a such a gene, that has become useful as a diagnostic tool in rhabdomyosarcomas. Beyond potential practical applications of cytogenetic and molecular analyses in the diagnosis of these tumors, we also review their impact on several philosophical concepts concerning soft tissue neoplasia.     

Genetics of pediatric central nervous system tumors

PURPOSE: Pediatric central nervous system (CNS) tumors comprise a wide variety of histologic subtypes ranging from the benign juvenile pilocytic astrocytoma to the highly aggressive atypical teratoid/rhabdoid tumor. Although some brain tumors are seen in association with inherited genetic disorders which predispose to malignancies, most are sporadic. Current knowledge regarding the cytogenetic and molecular genetic events which have been implicated in the development or progression of common brain tumors in children in the subject of this review. METHODS: Combined cytogenetic and molecular genetic approaches, including fluorescence in situ hybridization, have been used to identify genomic alterations in different histologic types of pediatric brain tumors. RESULTS: The most frequent abnormality in primitive neuroectodermal tumor/medulloblastoma is an i(17q), present in approximately 50% of cases. This finding implicates the presence of a tumor suppressor gene on 17p, which is important in tumor development. A number of genes on 17p have been eliminated as candidates for this locus, including TP53. A tumor suppressor gene in chromosome band 22q11.2 has been hypothesized to play a role in atypical teratoid/rhabdoid tumors, and positional cloning strategies are in progress to identify a rhabdoid tumor gene. Chromosome 22 deletions are also seen in meningiomas and a small percentage of ependymomas, but it is not yet known whether the same gene is responsible for more than one malignancy. With regard to childhood astrocytomas, tumor-associated genetic changes have not yet been identified for the common juvenile pilocytic or low grade diffuse astrocytoma. In contrast, malignant anaplastic astrocytomas and glioblastoma multiforme have abnormalities similar to those seen in adults, including loss of alleles on 17p13 and TP53 mutations, trisomy 7, EGFR rearrangements, and loss of chromosomes 10 and 22. CONCLUSIONS: The presence of tumor-associated genetic abnormalities has clinical utility in a differential diagnostic setting, and has lead to the identification of genes which contribute to tumorigenesis.     

Antimicrobial susceptibility of periodontopathic bacteria associated with failing implants

Histological, immunohistochemical, and flow cytometric characteristics of three unusual parotid gland tumors are described. The patients were adult white men with carcinoma ex pleomorphic adenoma, true malignant mixed tumor, and primary parotid gland chondrosarcoma. The carcinoma ex pleomorphic adenoma showed evidence of simultaneous epithelial, myoepithelial, and mesenchymal differentiation by immunohistochemistry. The true malignant mixed tumor exhibited variable positivity for two keratins, vimentin, proliferating cell nuclear antigen, Ki67, and p53. The chondrosarcoma initially stained for vimentin, S100, muscle-specific actin, proliferating cell nuclear antigen, and Ki67, but it lost actin expression in its first recurrence, accompanied by more extensive Ki67 staining. DNA ploidy varied from diploid to aneuploid with intratumoral variation in the carcinosarcoma. S-phase fractions ranged from 2.43% to 13.9%. The findings underscore the diversity of tumors that may be pathogenetically related to, and at times derived from, pleomorphic adenoma.     

Synovial sarcoma of the vulva: a report of two cases

We report two cases of synovial sarcoma arising in the vulva. The patients were 30 and 37 years old and presented with a painless mass that was interpreted clinically as a cyst. The tumors were 2.0 and 1.2 cm in greatest diameter. Histologically, they were composed of epithelial cells forming solid nests and gland-like and papillary structures surrounded by spindle-shaped cells. Immunohistochemically, the epithelial cells stained for cytokeratin and the spindle-shaped cells for vimentin. Ultrastructurally, the epithelial cells had prominent intercellular junctions and narrow microvilli and were separated from the spindle-shaped cells by a basal lamina. The spindle-shaped cells were closely apposed with focal intercellular contacts. One tumor recurred locally 3.5 years after excision, but the patient was alive and well 1 year after a re-excision and radiation therapy. The other patient was alive and well 4 years after an excision. These tumors are the first reported examples of synovial sarcoma arising in the vulva.