Renal angiomyolipoma is a benign neoplasm composed of variable proportions of blood vessels, smooth muscle, and adipose tissue. Smooth muscle, adipose tissue, blood vessels, and adjacent normal kidney tissue were separately microdissected from sections prepared from formalin-fixed, paraffin-processed tissues from angiomyolipomas from 18 women. X chromosome inactivation analysis using the methylation pattern at exon 1 of the human androgen receptor gene on chromosome Xq11-12 was used to study the clonal origin of each component. Nonrandom inactivation of X chromosomes was found in six of the 15 informative tumors. The smooth muscle and adipose tissue showed differing patterns of nonrandom inactivation of X chromosomes in five angiomyolipomas and the same pattern of nonrandom inactivation of X chromosomes in one. Samples from the blood vessels showed random inactivation of X chromosomes in all informative cases. Our data showed that the adipose tissue and smooth muscle cells of renal angiomyolipoma are both monoclonal but may arise independently. The coexistence of tumor subclones with morphologic heterogeneity can lead to the formation of a clinically detectable tumor.
ASCUS is the most common epithelial abnormality diagnosed in cytology laboratories in the US. Recently, the clinical importance of this diagnosis has been seriously questioned, with some investigators advocating elimination of this diagnostic category. This might be inappropriate if the ASCUS designation does define a population that is at significant risk for the development of dysplasia. Cytology and surgical pathology reports for all patients diagnosed as ASCUS in our laboratory during 1990 were reviewed. Patients with previous dysplasia or carcinoma were excluded from analysis. The pathology reports for the subsequent 9.1 yr were obtained and follow-up data collected. In 1990, 15,860 cervical cytology cases were examined in our laboratory. A diagnosis of ASCUS was made in 1,117 cases (7.0%). After excluding 345 patients with previous dysplasia or human papillomavirus-related diagnoses and 129 patients with no follow-up specimens, 643 study patients remained. Among these, the mean number of subsequent cervical smears was 4.3 (range, 1-18). Subsequent histologic material was available for 134 (20.8%) patients and the mean number of surgical specimens was 1.5 (range, 1-10). Squamous intraepithelial lesion (SIL) or dysplasia was subsequently diagnosed in 197 patients (30.6%). High-grade squamous intraepithelial lesion (HSIL) or at least moderate dysplasia was diagnosed in 64 patients (10.0%). In 21 cases (3.3%) the high-grade dysplasia developed more than 2 yr after the first ASCUS diagnosis. Follow-up disclosed no cases of invasive carcinoma. Among ASCUS patients followed for up to 9 yr, 20% develop only low-grade SIL or mild dysplasia and 10% develop HSIL or moderate or severe dysplasia. ASCUS should be retained as a diagnostic category since it identifies a significant percentage of patients who are at an increased risk for the development of cervical dysplasia.
Background.—Cytokeratin 7 (CK7) and cytokeratin 20 (CK20) are 2 types of intermediate filament protein. Expression of CK7 is seen in the majority of primary urinary bladder carcinomas. CK20 is restricted to superficial and occasional intermediate cells of the normal urothelium of the bladder. Aberrant CK20 expression has been documented in urothelial carcinoma and has proved useful as an ancillary diagnostic aid for urinary bladder tumor. Our hypothesis is that the pattern of CK7 and CK20 expression in metastatic urothelial carcinoma duplicates the expression of the same markers in the primary tumors. Therefore, immunohistochemical staining of metastatic tumors for these 2 markers may be helpful for differential diagnosis in ambiguous metastatic tumor deposits.
Objective.—To determine the concordance of CK7 and CK20 expression in primary bladder urothelial carcinoma and the matched lymph node metastasis.
Design.—We studied 26 patients with lymph node metastases who underwent radical cystectomy and bilateral lymphadenectomy for bladder carcinoma. Immunohistochemical staining for CK7 and CK20 was performed on formalin-fixed paraffin-embedded tissues containing primary cancers and lymph node metastases.
Results.—In all cases, there was a concordant expression of CK20 in the primary cancer and its matched lymph node metastasis. Twelve cases (46%) showed positive CK20 immunoreactivity in the primary tumor and its matched lymph node metastases, whereas 14 cases (54%) were negative for CK20 in both the primary tumor and lymph node metastasis. All cases showed positive CK7 immunoreactivity in the primary cancers and matched lymph node metastases.
Conclusions.—CK20 immunoreactivity is reliably observed in metastases from bladder cancer when the primary tumor expresses CK20.
Abstract. A 76-year-old man presented with vitritis in the absence of visible fundus lesions. Vitreal cytologie analysis revealed adenocarcinoma; immunostaining was consistent with a pulmonary origin. This case highlights the need to exclude metastasis to the vitreous in a patient with an oncologie history, even in the absence of visible posterior segment lesions. It also illustrates the utility of immunostaining to better determine the tissue of origin when a metastatic lesion is encountered. [Ophthalmic Surg Lasers 2000;31:155-156]
Context.—Loss of heterozygosity (LOH) on chromosomes 9p and 12q is common in germ cell tumors of the testis. Loss of heterozygosity of 17p13 has also been demonstrated in germ cell tumors. The incidence of LOH in epidermoid cysts, a possible special form of teratoma, has not been previously determined.
Objective.—To determine the frequency of LOH in epidermoid cysts.
Design.—Eight testicular epidermoid cysts and surrounding parenchyma were microdissected from formalin-fixed, paraffin-embedded tissue, and the genomic DNA was extracted using proteinase K. Polymerase chain reaction analysis targeted regions on chromosome 9p21 (D9S177 and D9S161 loci), chromosome 12q22 (D12S1051 locus), and chromosome 17p13 (TP53 locus). Gel electrophoresis followed by autoradiography was used to detect LOH.
Results.—All 8 of the epidermoid cysts were informative at a minimum of 1 of 4 loci. Three demonstrated LOH. In 2 tumors, LOH occurred on chromosome 9, and the third tumor demonstrated LOH on chromosome 12. Loss of heterozygosity on chromosome 17p13 was not present in any of the tumors.
Conclusions.—Epidermoid cysts harbor allelic loss at some of the same loci identified in malignant testicular germ cell tumors. Our findings support that some examples of epidermoid cysts are neoplastic, although their low frequency of LOH also supports that they are genetically different from malignant germ cell tumors.
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