Antimicrobial resistance and minimum inhibitory concentrations of bacteria isolated from bustards in the United Arab Emirates

BACKGROUND: Transforming growth factor-alpha (TGF-alpha) is a potent stimulator of cell proliferation in the liver and in liver tumors; however, its significance and association with hepatocyte proliferation remains unclear. METHODS: Expression of TGF-alpha and proliferation markers, such as proliferating cell nuclear antigen (PCNA) and cyclin A, were studied and correlated with each other in samples of tumor and surrounding liver tissue taken from nine patients with hepatoblastoma. An avidin-biotin-peroxidase immunohistochemical method was used for detection of TGF-alpha, PCNA, and cyclin A, and in situ hybridization was used to detect TGF-alpha mRNA. RESULTS: Two types of tumor cells of epithelial origin were distinguished based on the expression of TGF-alpha protein and RNA. The more differentiated "fetal" phenotype had a high expression of TGF-alpha and correlated with a low expression of proliferation markers. The less differentiated "embryonal" phenotype had low TGF-alpha expression and high proliferation activity. CONCLUSIONS: The expression of TGF-alpha is associated with a certain morphologic phenotype of tumor cells in hepatoblastoma; higher expression can be detected in more differentiated tumor cells. The negative correlation between the expression of TGF-alpha and proliferation markers suggests that the less differentiated embryonal cells do not depend on growth stimulation provided by TGF-alpha.     

Extrarenal rhabdoid tumors of soft tissue: a clinicopathologic and immunohistochemical study of 18 cases

Rhabdoid tumor is a well-accepted clincopathologic entity among childhood renal neoplasms; similar tumors have been described in extrarenal locations. We present the clinicopathologic profile and the immunohistochemical features of a series of soft tissue rhabdoid tumors. Twenty-eight cases coded as extrarenal rhabdoid tumor (ERRT), RT, possible ERRT, and "large cell sarcoma" were retrieved from the Armed Forces Institute of Pathology soft tissue registry. The tumors were reclassified according to strict criteria by light microscopy, clinical information, immunohistochemistry, and, in some cases, electron microscopy. Soft tissue rhabdoid tumor (STRT) was defined as (1) a tumor composed of noncohesive single cells, clusters, or sheets of large tumor cells with abundant glassy eosinophilic cytoplasm, an eccentric vesicular nucleus, and an extremely large nucleolus; (2) positivity for vimentin and/or cytokeratin or other epithelial markers by immunostaining; and (3) exclusion of other tumor types with rhabdoid inclusions (melanoma, other sarcomas, carcinoma). Eighteen cases met our criteria for soft tissue rhabdoid tumors. The median patient age was 13 years (range, 6 months to 56 years). Ninety-four percent of STRT cases were positive for vimentin and 59% for pan-cytokeratin. Sixty-three percent and 60% were positive for CAM 5.2 and EMA, respectively. Seventy-nine percent stained for at least one epithelial marker; 76% stained for both vimentin and epithelial markers simultaneously. Forty-two percent stained for MSA, and 14% for CEA and SMA. CD99, synaptophysin, CD57 (Leu-7), NSE, and focal S100 protein were identified in 75%, 66%, 56%, 54%, and 31% of the STRT cases, respectively. All STRT cases examined were negative for HMB-45, chromogranin, BER-EP4, desmin, myoglobin, CD34, and GFAP. Follow-up examination in 61% of the STRT patients revealed that 64% of patients died of disease within a median follow-up interval of 19 months (range, 4 months to 5 years); 82% had metastases to lung, lymph nodes, or liver; 22% had local recurrences before metastasis; and 18% were alive without known disease status (median, 5.5 years). Soft tissue rhabdoid tumor is a highly aggressive sarcoma, predominantly of childhood. Besides having nearly consistent coexpression of vimentin and epithelial markers, STRTs show positivity for multiple neural/neuroectodermal markers that overlap with those of primitive neuroectodermal tumor.     

Solitary cystic tumor of the pancreas: EUS-pathologic correlation

BACKGROUND: It is clinically important to distinguish neoplastic from non-neoplastic pancreatic cysts. METHODS: Retrospective correlations were made between pathologic and EUS data from 52 pancreatic solitary cystic tumors: mucinous cystadenoma (10), mucinous cystadenocarcinoma (7), serous cystadenoma (5), ductectatic mucinous cystic tumor (10), solid and papillary epithelial neoplasm (5), and non-neoplastic cyst (15). The mean tumor size was 3.5 cm (range, 1.2 cm to 6.0 cm). RESULTS: Six classifications of the internal structures of these cysts were developed: thick wall type, tumor protruding type, thick septal type, microcystic type, thin septal type, and simple type. Although all neoplastic cysts belonged to the first four types, all non-neoplastic cysts belonged to the last two types. The accuracy of EUS for differentiating tumors was estimated at 96% and 92%, respectively, by two observers. CONCLUSIONS: EUS may become a mandatory modality for differentiating pancreatic solitary cystic tumors and choosing an optimal treatment.     

Pancreatic cystic lesions of difficult diagnosis

Cystic lesions of the pancreas include pseudocysts (90%), cystic tumors and true cysts. Preoperative diagnosis will guide the therapeutic strategy. Certain malignant or potentially malignant cysts (mucinous cystadenomas and cystadenocarcinomas) should be removed surgically while others (pseudocysts and serous cystadenomas) are almost always benign. In 3 out of 4 cases, the clinical setting guides diagnosis and with adequate imaging (sonography, computed tomography, endosonography) the correct diagnosis can be obtained. Inversely, the nature of a unique macrocyst it is often difficult to identify. Puncture is useful to determine tumor markers which are sometimes helpful in complementing information provided by imaging techniques.     

Radiation diagnosis of spleen diseases]

The paper discusses the present-day radiation diagnosis of renal bulky formations: tumors and cysts. Based on the study of a great body of clinical data on 708 patients, the authors showed the potentialities of routine X-ray and currently available radiation techniques in the diagnosis of benign and malignant tumors and cysts of the kidney. Based on the data available in the literature and their own findings, the authors concluded that at the earliest stages of their preclinical development, tumors can be today diagnosed by a complete package of up-to-date diagnostic tools. Ultrasonic and computerized tomographies are of the highest informative value in diagnosing tumors and cystic formations. However, in some cases, a diagnosis is made via a routine excretory urography, angiography and needle biopsy. Excretory urography is of limited value for the diagnosis of renal bulky formations and it is used as an auxiliary mainly when a pathological process takes place in the renal hilus area. Angiography retains its significance as a supplementary technique. In the vast majority of cases, an accurate nosological diagnosis can be made on the basis of evaluation of the pattern of blood supply (the presence of abnormal vessels and their topographic features). The paper details the semiotics of a wide range of renal bulky processes by applying all currently available techniques of radiation diagnosis.     

Cytokine levels in cystic renal masses associated with renal cell carcinoma

PURPOSE: We compared cytokine levels in fluid from renal cysts with and without renal cell carcinoma. MATERIALS AND METHODS: Fluid was aspirated from 18 renal cysts without (benign) and 21 with renal cell carcinoma (malignant). Serum from patients with renal cell carcinoma and healthy controls was collected and cytokines were measured by enzyme-linked immunosorbent assay. RESULTS: Interleukin-6 (IL-6) and basic fibroblast growth factor concentrations were higher in malignant than benign cysts or serum (p <0.006). Epidermal growth factor levels were significantly higher in malignant cysts and serum than in benign cysts (p <0.01). IL-6 levels in malignant cysts positively correlated with the erythrocyte sedimentation rate (R=0.80) and C-reactive protein (R=0.86), and they were higher in grade 3 than in grade 2 tumors. Basic fibroblast growth factor levels were significantly higher in malignant cysts associated with hypervascular than hypovascular tumors (p=0.029). CONCLUSIONS: Cytokine levels in aspirated fluid may help to identify malignant renal cysts and indicate the characteristics of coexisting tumors.     

Failure in self care and heart failure, thiamine deficiency in geriatric patients

The ultrasonographic findings of 25 lesions in 23 patients with surgically proven ovarian masses were reviewed. There were 10 cystic teratomas, two simple cysts, two follicular cysts, two mucinous cystadenomas, two NHL, one corpus luteum cyst, one hydrosalpinx, one serous cystadenoma, one yolk sac carcinoma, one dysgerminoma, one embryonal carcinoma, and one mixed form (yolk sac carcinoma, choriocarcinoma). All patients were less than 15 years old. We classified all cases into four patterns: cystic, cystic with mural nodule, mixed, and solid. Eight lesions of the cystic pattern included two simple cysts, two follicular, cysts and one corpus luteum cyst. The other lesions were benign, too. Nine lesions with the cystic with mural nodule pattern consisted of eight cystic teratomas and one mucinous cystadenoma. All lesions were benign. The mixed pattern was seen in four lesions, half of which were malignant, i. e., one embryonal carcinoma and one yolk sac carcinoma. Four lesions with the solid pattern were all malignant masses: one dysgerminoma, two NHL and one mixed form. In this classification, the cystic and cystic with mural nodule patterns are benign, while mixed and solid patterns are highly suggestive of malignancy.     

Cytologic diagnosis of pancreatic cystic lesions. A prospective study of 28 percutaneous aspirates

PURPOSE: To prospectively evaluate fine needle aspiration biopsy (FNAB) of pancreatic cystic lesions. STUDY DESIGN: We performed a blind, prospective study on percutaneous aspirates from 28 radiographically identified cysts, including 6 inflammatory cysts (5 pseudocysts and 1 abscess), 4 serous cystadenomas, 1 cystic islet cell tumor, 5 mucinous cystic neoplasms, 6 mucinous cystadenocarcinomas and 6 nonpancreatic cysts. RESULTS: Four of six (67%) cystadenocarcinomas were identified as malignant, and the other two, which lacked sufficient morphologic criteria for malignancy, as consistent with mucinous cystic neoplasm. Two of five mucinous cystic neoplasms were correctly classified. One, which contained atypical cells, did not appear to be mucinous on the ThinPrep, and one, which lacked an epithelial component, was suggested because of the presence of mucin in the background. The fifth one contained inflammatory cells only. One of four serous cystadenomas produced a diagnostic specimen. FNAB of the cystic islet cell tumor was nondiagnostic. Five of six inflammatory cysts (83%) were correctly diagnosed, whereas one case produced an acellular, nondiagnostic specimen. Six of 28 (23%) cases were nonpancreatic cysts, aspirated under the presumption that they were pancreatic cysts based on radiologic studies: only one case, a papillary cystadenocarcinoma of the stomach, was correctly diagnosed; the other five cases were nondiagnostic, and in two of these the assumption that the cysts were pancreatic in origin precluded an accurate classification. CONCLUSION: FNAB of pancreatic cystic lesions can differentiate mucinous from nonmucinous pancreatic cysts and provide definitive evidence of malignancy. In some cases, serous cystadenomas can be diagnosed. Pseudocysts can be suspected on the basis of an inflammatory smear lacking both epithelial cells and background mucin, but this finding is not specific. Nonpancreatic lesions constitute a significant percentage of cases aspirated as pancreatic cysts and present a major pitfall in cytologic interpretation.     

Invasive squamous cell carcinoma arising from asymptomatic choristomatous cysts of the orbit. Two cases and a review of the literature

BACKGROUND: Epithelial choristomatous cysts are common orbital lesions, the most frequent of which are dermoid or epidermoid tumors. Massive enlargement or extraorbital extension of these benign lesions may occur. Malignant transformation of the epithelial lining of epidermoid cysts is rarely reported. METHODS: Two patients are presented in whom the epithelial lining of a previously asymptomatic choristomatous cyst of the orbit underwent malignant transformation to produce invasive squamous cell carcinoma. The unusual origin and clinical presentation of the lesions caused a delay in the diagnosis and therapy in both patients. Metastatic workup was negative in both patients, who underwent resection of their tumors via orbital exenteration with craniofacial resection. Reported cases of malignant transformation in analogous choristomatous cysts elsewhere in the cranium are reviewed. RESULTS: One patient is alive and well without recurrent disease 40 months postoperatively. The second patient died of a pulmonary embolus 2 months postoperatively. Autopsy showed no residual tumor. Overall, only 3 of 18 reported patients with epidermoid choristoma of the head and orbit with malignant transformation were alive when reported. CONCLUSIONS: Malignant squamous metaplasia is believed to be a rare complication of orbital dermoid or epidermoid cysts, with only two previously reported cases. However, malignant transformation is relatively frequent in analogous epidermoid cysts found elsewhere in the cranial vault, especially after incomplete excision. These reports encourage the complete removal of epithelial choristomas of the orbit.     

Failure of the polyethylene after bipolar hemiarthroplasty of the hip. A report of five cases

Due to the difficulties in separating malignant and benign ovarian cysts by transvaginal ultrasound and other techniques, there is a need for biochemical markers in serum or cyst fluids. In the present study we have evaluated the levels of the chemokine interleukin-8 (IL-8) in ovarian cysts. IL-8 is known to be expressed in the normal ovary and to influence proliferation and angiogenesis of several nonovarian types of tumors. Cyst fluids from benign (n = 15) and malignant (n = 13) ovarian tumors were analyzed. The levels of IL-8 were found to be significantly (13-fold) higher in cyst fluids from malignant tumors (18.1 +/- 7.5 ng/ml; mean +/- SE) compared to benign cysts (1.3 +/- 0.7 ng/ml). The plasma levels of IL-8 were considerably lower (2.9 and 0.3% of levels in benign and malignant cyst fluids, respectively) than in cyst fluids. No difference in the plasma levels of patients with benign or malignant tumor could be detected. In contrast, the levels of CA 125 were significantly higher in plasma of patients with malignant disease with the inverse relation in cyst fluids. In conclusion, the levels of IL-8 are markedly elevated in cyst fluid from malignant tumors compared to benign. This specific increase indicates a role for this cytokine in ovarian tumor biology.     

Partial nephrectomy in partially differentiated cystic nephroblastoma

OBJECTIVE: To report on a case of cystic partially differentiated nephroblastoma in an adult female patient that was treated by partial nephrectomy. METHODS/RESULTS: A 21-year-old female patient with multicystic lesions was submitted to partial nephrectomy involving the lower pole of the right kidney. The presence of embryonal blastema in the septae that separated the cysts was diagnostic of cystic partially differentiated nephroblastoma. CONCLUSIONS: Cystic partially differentiated nephroblastoma can be considered to be a well differentiated variant of nephroblastoma (Wilms' tumor). Due to its benign nature, treatment is by conservative renal surgery, if technically possible.     

Morphology of cystic renal lesions. Lectin and immuno-histochemical study

Renal cystic disease include heritable, developmental and acquired disorders. Morphological features were extensively studied mainly in cases of autosomal dominant polycystic and experimentally induced cystic disorders. We report the immunohistochemical (cytokeratin, epithelial membrane antigen, vimentin, Tamm-Horsfall protein, proliferating cell nuclear antigen) and lectin-binding (soybean agglutinin, Dolichos biflorus agglutinin) profile of cystic kidneys from 9 surgically removed and 21 autopsy cases. The primary renal diseases displayed great diversity. Beside polycystic kidney diseases we studied cysts associated to renal neoplasm, hemodialysis, nephrosis syndrome and chronic transplant rejection. Cystic epithelium demonstrated positive reactions with distal tubular markers (epithelial membrane antigen, cytokeratin) or collecting duct (soybean agglutinin, Dolichos biflorus agglutinin) and Henle loop markers (Tamm-Horsfall protein) but the latter in lesser extent. The large number of the vimentin positive cases are suggestive to dedifferentiation or cellular regeneration. The former might be underlined by the diffuse cytoplasmic or basolateral membrane staining of the epithelial membrane antigen in some cystic epithelial cells. Not the cystic epithelium but rather the neighbouring non-dilated tubular cells and interstitial cells presented proliferative activity which was most intense in areas where vimentin and variable nephron segment markers in the same tissue were expressed. Positive reaction of the type IV basement membrane collagen and the rate of the inflammation failed to show similar connection. This finding suggests the importance of the inflammatory cells in the development and/or expansion of the cysts.     

Primary germ cell tumors of the mediastinum: I. Analysis of 322 cases with special emphasis on teratomatous lesions and a proposal for histopathologic classification and clinical staging

BACKGROUND: Primary germ cell tumors of the mediastinum are unusual neoplasms with histopathologic features that are similar to those of germ cell tumors in the gonads. However, their clinical features, behavior, and spectrum of pathologic features in the mediastinum have not yet been fully defined. METHODS: The clinical and pathologic features of 322 cases of primary mediastinal germ cell tumors were reviewed, with special emphasis on teratomatous lesions. The tumors were divided into groups according to their histologic features and correlated with their order of frequency, patient gender and age distribution, and morphologic features. A clinical staging scheme based on the extent and location of the lesions was devised. RESULTS: The overwhelming majority of patients were men (320); only 2 were women (both had teratomatous lesions with additional malignant components). The patients' ages ranged from 1 to 79 years (mean, 40 years). Histologically, all types of germ cell tumors were represented, including 138 teratomas (87 mature teratomas, 6 immature teratomas, and 45 teratomas with additional malignant components); 120 seminomas; 52 nonseminomatous, nonteratomatous germ cell tumors (38 yolk sac tumors, 6 embryonal carcinomas, and 8 choriocarcinomas); and 12 combined germ cell tumors without teratomatous components. The teratomatous lesions with additional malignant components were further separated into subtypes based on the histologic types of their malignant components, i.e., epithelial, mesenchymal, etc. Clinical staging was possible in 242 cases, with 191 cases (79%) in Stage I, 4 cases (1.6%) in Stage II, and 47 cases (19.4%) in Stage III. In each group, the clinical staging correlated well with the clinical outcome for the majority of patients. CONCLUSIONS: The results of this study showed that mediastinal germ cell tumors have demographic and histopathologic distributions similar to those of tumors occurring in the male gonads, with teratomatous and seminomatous lesions being the most common. Among the nonseminomatous germ cell tumors in this study, the yolk sac tumors appeared to occur the most frequently (the ratio of yolk sac tumor occurrence to embryonal carcinoma occurrence was 6.1:1). In addition, the subclassification of teratomas with additional malignant components based on the histologic types of malignancies may lead to more therapy choices for patients. At the same time, the use of a clinical staging scheme may be of value in predicting clinical outcome and planning therapy.     

Autosomal dominant medullary cystic kidney disease: evidence of gene locus heterogeneity

Autosomal dominant medullary cystic kidney disease (ADMCKD; synonym: medullary cystic disease, MCD) is an autosomal dominant kidney disorder, sharing morphological and clinical features with recessive juvenile nephronophthisis (NPH), such as reduced urinary concentration ability and multiple renal cysts at the corticomedullary junction. While in NPH end-stage renal disease (ESRD) occurs in adolescence, ADMCKD leads to ESRD in adulthood. Recently a gene locus for ADMCKD has been localized to chromosome 1q21 in two large Cypriot families. This prompted us to examine linkage in three ADMCKD-families, using the same set of polymorphic microsatellite markers spanning the critical region on chromosome 1q21. Haplotype analysis revealed that none of the three families showed linkage to this locus, thus demonstrating evidence for genetic locus heterogeneity. Additional linkage analysis studies need to be performed in order to identify further gene loci cosegregating with this autosomal dominant kidney disorder.     

Detection of 8-epi prostaglandin F2alpha in an extract of epidermal secretion of the catfish from the Arabian Gulf

Cell proliferation and apoptosis were studied in 8 patients with inherited polycystic kidney disease and in 34 patients with acquired cystic kidney conditions including solitary and multilocular cysts and segmental tubular dilation. Intact renal tissue of 20 surgically removed tumorous kidneys served as control. Cell proliferation and apoptosis were demonstrated by immunohistochemical and in situ end-labeling methods. The percentage of positively stained nuclei was calculated and statistically analyzed. Both apoptosis and cell proliferation were significantly higher (p<0.001) in polycystic kidney disease. The percentage of positively stained nuclei in the whole kidney tissue with acquired cysts did not differ from controls although cell proliferation was significantly higher (p<0.001) in cells lining the cysts. Apoptotic cells were rarely found in the cystic epithelium or were even absent in these cases. Our data indicate that while polycystic kidneys seem to be characterized by abnormal cell survival, acquired renal cysts have different behavior in which so far unknown intracellular changes are more likely to cause tubular distension probably through induced cell proliferation.     

Soluble receptor for urokinase plasminogen activator in both full-length and a cleaved form is present in high concentration in cystic fluid from ovarian cancer

We assayed the levels of soluble urokinase plasminogen activator receptor (su-PAR) with an ELISA in various body fluids from 77 patients with benign or malignant ovarian tumors, histologically classified as follows: benign; possibly malignant (borderline); and well, intermediately, and poorly differentiated malignant. The concentration of su-PAR in fluid from malignant cysts was extremely high, approximately 10-fold higher than the concentration in ascitic fluid and approximately 100-fold higher than that in blood. Also, the concentration in malignant cysts was approximately 10-fold higher than the concentration in benign cysts. Such high concentrations of su-PAR were found not only in truly malignant but also in possibly malignant cysts. Thus, we suggest that the concentration of su-PAR in cystic fluid can serve as a marker, allowing early diagnosis of malignant ovarian cysts. The concentration of su-PAR in fluid aspirated transvaginally with ultrasonographic guidance can be used to discriminate possibly and truly malignant cysts from benign cysts without surgery. The high concentrations of su-PAR in ovarian cystic fluids allowed us to characterize the molecular forms. Cross-linking of a radiolabeled ligand to the receptor demonstrated that at least a fraction of su-PAR was able to bind the ligand. A cleaved form of the receptor constituting domains 2 and 3 was detected with Western blotting. The cleaved receptor, which is devoid of the ligand-binding domain 1, has not previously been demonstrated in body fluids; it has only been demonstrated on cell surfaces. su-PAR domains 2 and 3 were found in cystic fluids from both malignant and benign ovarian tumors.     

Field test for mechanical efficiency evaluation in matching volleyball players

OBJECTIVE: To evaluate the histologic features and biologic behavior of unclassified sex cord-stromal tumors. PATIENTS: The eight patients' ages at presentation ranged from 14 to 83 years. Presenting symptoms and physical findings included abdominal pain, abnormal uterine bleeding, ascites, and abdominal and pelvic masses. One patient also had bilateral sex cord tumors with annual tubules and probable Peutz-Jeghers syndrome. RESULTS: The tumors ranged from 4 to 27 cm in diameter and were described as partially encapsulated, solid, and cystic. Histologically, the tumors were composed of diffuse proliferations of sex cord cells, with cords, tubules, and follicle-like structures. The stromal cells were spindle-shaped, with scanty cytoplasm. The neoplasms were vimentin-positive and, sometimes, cytokeratin CAM 5.2- and AE1/3-positive and epithelial membrane antigen-negative. Six patients were disease-free from 2 months to 6 years after operation. One patient was lost to follow-up. The patient with probable Peutz-Jeghers syndrome had a tumor with unusual morphology and died of the neoplasm 4 years after the diagnosis. Three of 32 other cases with clinical follow-up mentioned in the pathology literature have been associated with a malignant behavior. CONCLUSION: The biologic behavior of unclassified sex cord-stromal tumors resembles that of Sertoli-Leydig cell tumors of intermediate differentiation rather than poorly differentiated tumors, which might have been expected in view of the lack of specific differentiation. This finding is important with regard to postoperative management.     

Cystic renal cell carcinoma is cured by resection: a study of 24 cases with long-term followup

PURPOSE: The true incidence and biological behavior of cystic renal cell carcinoma are not known. To our knowledge we present the largest series of patients with cystic renal cell carcinoma with long-term followup. MATERIALS AND METHODS: We reviewed the Mayo Clinic surgical pathology files of renal cell cancer cases with a cystic component resected from 1969 to 1997, and arbitrarily chose 75% tumor involvement by cysts as a cutoff for inclusion in the study. RESULTS: We identified 24 cases of clear cell renal cell carcinoma with 75% or greater involvement by cysts comprising 0.79% of 3,047 renal cell cancer cases resected at our institution between 1969 and 1997. Mean patient age was 62.7 years (range 40 to 83). A total of 11 patients (46%) underwent radical nephrectomy, 4 (17%) simple nephrectomy, 3 (12%) partial nephrectomy and 6 (25%) tumor enucleation. Mean tumor involvement by cysts was 84% (range 75 to 95) and in 11 cases (46%) involvement was 90% or greater. Cancer stage was T1 in 20 patients (83%), T2 in 1 (4.4%) and T3a in 4 (12.5%). Cancers were diploid in all but 1 case. Mean followup was 77.6 months (range 8 to 428, median 51). A total of 22 patients (92%) had no evidence of cancer and 2 died of intercurrent disease. CONCLUSIONS: Our results indicate that cystic renal cell carcinoma is uncommon and usually cured by resection, regardless of size, stage or number of cysts. These patients may benefit from nephron sparing surgery, such as partial nephrectomy.     

Pleomorphic xanthoastrocytoma: DNA flow cytometry and outcome analysis of 12 patients

BACKGROUND: Pleomorphic xanthoastrocytoma (PXA) is an astrocytic tumor occurring primarily in childhood and adolescence with some malignant histologic features but a relatively slow clinical course. However, some tumors progress more rapidly and can undergo malignant degeneration. The authors attempted to determine whether various histologic features or tumor cell proliferative indices might help identify lesions at risk for early progression and distinguish PXAs from malignant gliomas. METHODS: In a retrospective study of 12 patients with PXA, the tumor's histologic features and DNA flow cytometric parameters were compared with their clinical course. DNA flow cytometry values for the S- and G2-phase of the PXAs also were compared with control group samples of malignant and low grade astrocytomas. RESULTS: Of the 12 tumors at initial diagnosis, 5 were considered typical PXAs whereas 7 had some atypical features (4 with paucity of reticulin fibers, 1 with focal necrosis, and 2 with both atypical reticulin and focal necrosis). During the follow-up period (range, 3.75-11 years; mean, 6.8 years), 2 patients had recurrences; 1 atypical reticulin PXA progressed to glioblastoma after 6.5 years and the 1 tumor with focal necrosis recurred at 6 months and again at 2 years with typical histologic features. DNA flow cytometry parameters of the typical PXA group were similar to values for malignant astrocytoma and significantly higher than values for control specimens of low grade astrocytomas. There were no distinctive DNA flow cytometric features that could distinguish this last tumor from others with a more benign clinical course. CONCLUSIONS: Measurements of the S-phase and G2-phase obtained from DNA flow cytometry and atypical histologic features cannot reliably identify PXA patients at risk for early progression and overall are significantly higher than values obtained for low grade gliomas. Therefore, frequent (i.e., two to three times per year) postoperative clinical and radiologic examinations are necessary to judge the appropriateness of adjuvant therapy in patients with PXA. The paradox of slow growth but DNA flow cytometry consistent with aggressive malignant lesions may represent a cell-cycle arrest mechanism in these lesions that could be verified in subsequent studies.     

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.