Nasopharyngeal extension of glomus tympanicum: an unusual clinical and imaging manifestation.

Nasopharyngeal extension of the glomus tympanicum is rare. Only 2 cases have been reported in the literature to date. We present a reported case of a large nasopharyngeal extension of recurrent glomus tympanicum, with various kinds of imaging and histopathology and a review of the literature.

Accuracy of intraoperative frozen section in diagnosis of ovarian tumors.

OBJECTIVE: To determine the accuracy of intraoperative frozen section diagnosis of ovarian tumors according to malignancy status. MATERIAL AND METHOD: From May, 1999 to October, 2004 at Songklanagarind Hospital, a total of 229 ovarian specimens were transferred from the operating room to the Department of Pathology for intraoperative frozen section. All cases of deferred diagnosis and disagreement between frozen and permanent paraffin section were reviewed. RESULTS: Intraoperative frozen section diagnosis of all 229 ovarian specimens revealed 54.1% benign tumors, 8.3% borderline tumors, 30.6% malignant tumors, and 7% deferred diagnoses. The final paraffin section diagnoses revealed 52.4% benign tumors, 9.2% borderline tumors, and 38.4% malignant tumors. Mean tumor diameter of the agreement cases were 12.58 +/- 5.39 cm, disagreement cases were 17.64 +/- 6.83 cm, and deferred cases were 19.33 +/- 6.50 cm. The mean diameter of mucinous tumors was significantly different comparing between disagreement cases to agreement cases and deferred cases to agreement cases. The overall accuracy was 89.7%. Sensitivity was highest in the benign group at 98.2% and lowest in the borderline group at 57.1%. The sensitivity and specificity for benign, borderline, and malignant tumors were 98.2%, 57.1%, 86.1%, and 87.0%, 96.4%, 98.5%, respectively. The Positive Predictive Value (PPV) and Negative Predictive Value (NPV) for benign, borderline, malignant tumors were 89.5%, 63.2%, 97.1% and 97.8%, 95.4%, 92.3%, respectively. CONCLUSION: Intraoperative frozen section diagnosis appears to be an accurate technique for the histopathologic diagnosis of ovarian tumors. However, limitations in use of frozen section must be recognized such as large specimens, especially mucinous subtype. Regular re-evaluation or consultation concerning disagreements between frozen section diagnosis and final permanent paraffin diagnosis should be conducted by both surgeons and pathologists as part of quality assurance to determine the most appropriate intraoperative management for patients with ovarian tumors.

Transcriptional regulation of insulin-like growth factor-I receptor gene expression in prostate cancer cells.

A marked decrease in the type 1 insulin-like growth factor (IGF) receptor (IGF-IR) occurs in prostate epithelial cells during transformation from the benign to the metastatic state. One of the principal regulators of IGF-IR gene expression, the WT1 tumor suppressor, is expressed in prostate cancer and in prostate cancer cell lines. The purpose of this study was to determine whether the decrease in IGF-IR expression was transcriptionally regulated, and whether WT1 action may be involved in the repression of the IGF-IR gene in prostate cancer cells. The P69 cell line was derived by immortalization of human primary prostate epithelial cells with simian virus-40 T antigen and is rarely tumorigenic. The M12 line was derived from the P69 line by selection for tumor formation in nude mice and is tumorigeneic and metastatic. P69 cells express 20,000 IGF-IR/cell, whereas M12 cells express 3,500 IGF-IR/cell. These differences in receptor number are reflected in proportional differences in IGF-IR mRNA levels. To assess IGF-IR promoter activity in these cell lines, each was transiently transfected with luciferase reporter vectors containing the IGF-IR gene transcription start site and 476 bp of 5'-flanking sequence, 640 bp of 5'-untranslated region sequence, or both regions. The promoter activity of the full-length construct was 50% lower (P < 0.01) in M12 cells compared with P69 cells, the activity of the 5'-flanking region construct was 53% lower (P < 0.0001), and that of the 5'-untranslated region construct was 36% lower (P = 0.01). P69 clones stably transfected with a WT1 expression vector exhibited decreased expression of the endogenous IGF-IR gene and decreased promoter activity in transient transfection assays with IGF-IR promoter constructs containing multiple WT1 binding sites. The observed reduction in endogenous IGF-IR expression was sufficient to inhibit IGF-I-stimulated cell proliferation. These data suggest that most of the decreased expression of the IGF-IR seen in malignant prostate epithelium is the result of transcriptional repression of the IGF-IR gene, and that this repression may be due in part to the increased expression of the WT1 tumor suppressor in metastatic prostate cancer.

Detection of a novel truncated WT1 transcript in human neoplasia.

BACKGROUND: The Wilms' tumor 1 (WT1) gene encodes a transcription factor critical in urogenital development. Using a new model of prostate cancer progression that permits comparison of the cellular and molecular properties of increasingly aggressive sublines of simian virus 40 large T-antigen-immortalized human prostate epithelial cells within the same lineage, the role of WT1 in tumorigenesis was investigated. METHODS AND RESULTS: Using RT-PCR and northern blotting, we identified a novel truncated WT1 transcript in these prostate cancer cell lines. This 2.1-kb transcript consisted of the coding region of the zinc-finger domain of WT1, together with a portion of intron 5 at the 5' end of the transcript. Furthermore, two peptides were detected by western blotting using antibodies to epitopes of the COOH terminus of WT1. Using RT-PCR, the 2.1-kb transcript was also detected in leukemia cell line K562, breast cancer cell line MCF7, and blood samples from patients with acute leukemia. CONCLUSION: These novel findings in both cell lines and patient-derived specimens suggest this new WT1 gene alteration has a potential role in the development of new diagnostic assays for some human malignancies.