Christine F. Stephenson

CD5- mantle cell lymphoma.

Mantle cell lymphoma (MCL) typically expresses B-cell antigens and CD5 and overexpresses bcl-1 protein. However, unusual cases of bcl-1+ and CD5-MCL have been observed, posing a practical challenge for correct diagnosis and management. We identified 25 cases (48 samples) of bcl-1+ and CD5- lymphoma. CD5 expression was assessed by flow cytometric analysis alone (1 case), immunohistochemical analysis alone (17 cases), or dual flow cytometric/immunohistochemical methods (7 cases). The morphologic features were consistent with MCL with centrocytic cytomorphology in 20 cases and blastic variant in 5 cases. The t(11;14) was confirmed in 8 of 11 cases by fluorescence in situ hybridization of paraffin-embedded tissue. Cytogenetic analysis revealed the t(11;14) within a complex karyotype in 2 additional cases. These data show that MCL may lack CD5 expression. Evaluation of bcl-1 expression by immunohistochemical analysis or molecular genetics may be indicated if MCL is suspected clinically or morphologically despite a lack of CD5 expression.

Cytogenetic and pathologic aspects of Ewing's sarcoma and neuroectodermal tumors

Diagnostic classification of poorly differentiated, round cell, primitive neuroectodermal neoplasms, including Ewings sarcoma, peripheral neuroepithelioma, Askins tumor, and esthesioneuroblastoma, is challenging to the surgical pathologist using conventional histopathologic approaches because of very similar and overlapping morphologic and cytologic features. Furthermore, distinguishing these neoplasms from neuroblastoma, embryonal rhabdomyosarcoma, small cell osteogenic sarcoma, and non-Hodgkins lymphoma can be difficult. This paper describes and reviews the cytogenetic and molecular genetic changes in these tumors and demonstrates how the ability to detect these changes has enabled a greater understanding of the histogenesis, classification, diagnosis, and prognosis of these neoplasms.

Cytogenetic and fluorescence in situ hybridization analysis of breast fibroadenomas

We report cytogenetic and fluorescence in situ hybridization (FISH) analysis findings in 7 patients with breast fibroadenomas (FA). Three patients were cytogenetically abnormal. One patient had a translocation t(3;5)(p22;q13), the second had trisomy 8, and the third two clones, 47, XX, +11 and 47,XX, +10.

Chromosome abnormalities in breast fibroadenomas

Cytogenetic analysis of 25 breast fibroadenomas (FA) showed clonal chromosome alterations in three cases. Insertion (12;?) (q15;?) and deletion (2) (q14q31 or q32) were detected as a sole change in cases 1 and 3, respectively. Case 2 displayed the karyotype 45,XX,t(1;8;16)(q25;q23;q22-23), add (7)(p14), rea(15), -17. The present findings are discussed together with the reports on FA in the literature.

Ring Chromosome in a Dermatofibrosarcoma Protuberans

We report the cytogenetic findings in a case of dermatofibrosarcoma protuberans in a 40-year-old male. Chromosome analysis revealed one clone consisting of +7, +11, +13, +14, +15, and a ring chromosome. This is consistent with two previously reported cases, each of which also had a single ring chromosome.

del(6q) as a possible primary change in malignant mesothelioma

Detailed cytogenetic and fluorescence in situ hybridization analysis of an untreated pleural malignant mesothelioma revealed two clonal cell populations, both with a single abnormality affecting chromosome 6. The majority of cells had a deletion together with an inversion of the long arm of chromosome 6, while a smaller population showed loss of this chromosome. The normal 6 was retained. Most reports show that mesotheliomas are characterized by complex karyotypes, involving numerous chromosomes. Abnormalities of chromosome 6 (particularly deletions of the long arm) are among the consistent changes. Our case apparently is the first report of a mesothelioma with a single change involving chromosome 6, which could be the primary cytogenetic change.

Analysis of a giant marker chromosome in a well-differentiated liposarcoma using cytogenetics and fluorescence in situ hybridization.

Well-differentiated liposarcomas (LPS) are cytogenetically very complex, characterized by giant marker chromosomes, ring chromosomes, and telomeric associations. We report a case of well-differentiated LPS in which the only cytogenetic anomaly was an additional giant marker. In an attempt to identify the origin of this marker, centromeric probes (chosen on the basis of the morphology of the marker) to chromosomes 1,2,3,4,6,7,8,9,10,11,12,16,17, and X and a shared satellite probe for chromosomes 1,5, and 19, were used with fluorescence in situ hybridization (FISH). This was successful at eliminating certain chromosomes as candidates for centromeric trisomy but could not identify the origin of the marker. This case is unusual in that it does not conform to the typical cytogenetic pattern for well-differentiated LPS and is the first known example with an apparently normal diploid karyotype with only one additional change.

Assessment of erythroid dysplasia by “Difference from normal” in routine clinical flow cytometry workup

While multidimensional flow cytometry (MDF) has great utility in diagnostic workups of patients with suspected myelodysplastic syndromes (MDS), only the myeloid lineage has demonstrated reproducible abnormalities from multiple laboratories. With the effects of ammonium chloride (NH4Cl) lysis on erythroid progenitors previously described, we applied this protocol to a patient cohort with diagnosed MDS to investigate phenotypic abnormalities that indicate erythroid dysplasia.

Array-Based Karyotyping in Plasma Cell Neoplasia After Plasma Cell Enrichment Increases Detection of Genomic Aberrations

The discovery of genomic abnormalities present in monoclonal plasma cells has diagnostic, prognostic, and disease-monitoring implications in plasma cell neoplasms (PCNs). However, technical and disease-related limitations hamper the detection of these abnormalities using cytogenetic analysis or fluorescence in situ hybridization (FISH). In this study, 28 bone marrow specimens with known PCNs were examined for the presence of genomic abnormalities using microarray analysis after plasma cell enrichment. Cytogenetic analysis was performed on 15 of 28 samples, revealing disease-related genomic aberrations in only 3 (20%) of 15 cases. FISH analysis was performed on enriched plasma cells and detected aberrations in 84.6% of specimens while array comparative genomic hybridization (aCGH) detected abnormalities in 89.3% of cases. Furthermore, aCGH revealed additional abnormalities in 24 cases compared with FISH alone. We conclude that aCGH after plasma cell enrichment, in combination with FISH, is a valuable approach for routine clinical use in achieving a more complete genetic characterization of patients with PCN.

Male-To-Female Sex Ratios of Abnormalities Detected by Fluorescence in Situ Hybridization in a Population of Chronic Lymphocytic Leukemia Patients

Distorted sex ratios occur in hematologic disorders. For example, chronic lymphocytic leukemia (CLL) displays disproportionate sex ratios with a large male excess. However, the underlying genetics for these disparities are poorly understood, and gender differences for specific cytogenetic abnormalities have not been carefully investigated. We sought to provide an initial characterization of gender representation in genetic abnormalities in CLL by using fluorescence in situ hybridization (FISH). We confirm the well known skewed male-tofemale (M/F sex ratio) of ~1.5 in our CLL study population, but also determine the genotypic M/F sex ratio values corresponding to specific FISH DNA probes. Genetic changes in CLL detectable by four FISH probes were statistically compared with respect to gender. Initial FISH evaluations of 4698 CLL patients were retrospectively examined and new findings of the genotypic M/F sex ratios for these probes are reported. This study represents the largest CLL survey conducted in the United States using FISH probes. The CLL database demonstrated that FISH abnormalities (trisomy 12, 13q14.3 deletion and 17p13.1 deletion) probes had skewed M/F ratios of ~1.5. Also, by statistical analysis it was shown that ATM gene loss (11q22.3q23.1 deletion) solely or with other abnormalities was considerably higher in males with an M/F ratio of 2.5 and significantly different from M/F ratios of 1.0 or 1.5. We hypothesize that interactions involving these autosomal abnormalities (trisomy 12, and deletions of 11q22.3, 13q14.3, and 17p13.1), and the sex chromosomes may provide the genetic basis for the altered phenotypic M/F ratio in CLL.