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PubMed1992

Isolation and initial characterization of a new virus: Micro-Foci inducing virus or MFV.

Infectious and transforming activity was obtained from cultures of a large kidney tumour with very high N-myc amplification. The patient belonged to a cluster of neuroblastoma cases diagnosed in Southern Louisiana in 1986-1988. Infection with ultra-filtered supernatants from neuroblastoma cultures caused the appearance of small foci of rounded cells with neural features and the presence of virus was indicated by electron microscopy: the virus was called Micro-Foci inducing virus or MFV. Infected young adult rats did not develop overt disease, but 11/11 of the litters from infected animals developed a very dramatic and highly lethal syndrome which could resemble neuroblastoma symptoms. N-myc amplification disappeared in very early cultures of the tumour, but it was subsequently detected in MFV-infected cell cultures.

Animals↗

PubMedDate not supplied

Amplification and enhanced expression of the c-myc oncogene in mouse SEWA tumour cells.

SEWA tumour cells are derived from an osteosarcoma induced in an A.SW mouse by infection with polyoma virus. Cytogenetic analyses have revealed three different characteristic chromosomal abnormalities diagnostic for the presence of amplified genes: 'double minutes' (DMs), homogeneously staining chromosomal regions (HSRs) and C-bandless chromosomes (CMs; for review see ref. 2). DMs may undergo fluctuation in number depending on the conditions in which the cells grow. Their number usually increases after injection of cells into a mouse and often is reduced to undetectable levels when the cells are explanted back into tissue culture; when the cells are re-introduced into the mouse, they again acquire multiple DMs. We show here that cells of SEWA lines carrying DMs, HSRs or CMs contain amplified copies of the proto-oncogene c-myc and enhanced levels of c-myc messenger RNA and c-myc protein. DMs or CMs are the sites of c-myc amplification in two different SEWA lines.

Animals↗

PubMed2005

CpG island methylator phenotype is a strong determinant of poor prognosis in neuroblastomas.

Neuroblastoma, one of the most common pediatric solid tumors, is characterized by two extreme disease courses, spontaneous regression and life-threatening progression. Here, we conducted a genome-wide search for differences in DNA methylation that distinguish between neuroblastomas of the two types. Three CpG islands (CGI) and two groups of CGIs were found to be methylated specifically in neuroblastomas with a poor prognosis. By quantitative analysis of 140 independent cases, methylation of all the five CGI (groups) was shown to be closely associated with each other, conforming to the CpG island methylator phenotype (CIMP) concept. The presence of CIMP was sensitively detected by methylation of the PCDHB CGIs and associated with significantly poor survival (hazard ratio, 22.1; 95% confidence interval, 5.3-93.4; P < 0.0001). Almost all cases with N-myc amplification (37 of 38 cases) exhibited CIMP. Even in 102 cases without N-myc amplification, the presence of CIMP (30 cases) strongly predicted poor survival (hazard ratio, 12.4; 95% confidence interval, 2.6-58.9; P = 0.002). Methylation of PCDHB CGIs, located in their gene bodies, did not suppress gene expression or induce histone modifications. However, CIMP was significantly associated with methylation of promoter CGIs of the RASSF1A and BLU tumor suppressor genes. The results showed that neuroblastomas with CIMP have a poor prognosis and suggested induction of silencing of important genes as an underlying mechanism.

Cell Line, Tumor↗

PubMed2004

[Management strategy in neuroblastoma].

Neuroblastoma is one of the most common (7-10%) childhood cancers and the most frequent malignancy in neonates and infants. The disease course depends not only on the child's age and clinical stage but also on other factors, especially cytogenetic and molecular abnormalities. The currently employed treatment modalities should cure at least 60% of all neuroblastoma patients. But, in a very high risk group (age >1 year, stages 2 and 3 with N-MYC amplification, all patients with stage 4), which constitutes more than half of patients, results of very intensive treatment remain still unsatisfactory. Fewer than one-third of children over one year of age with stage 4 neuroblastoma are expected to survive. The success of treatment depends not only on treatment, which intensity is tailored to the risk of individual patients, but also on detailed and precise diagnosis and therapy monitoring. Children with neuroblastoma, regardless of the presenting signs and age, should undergo comprehensive evaluation, including genetics and molecular studies. Majority of infants with neuroblastoma have a good prognosis, but choice of therapy in these patients depends on disease stage, critical organ function (Philadelphia score), surgical treatment possibilities and on the presence of the N-MYC amplification. Further improvement of therapeutic strategy, especially for advanced neuroblastoma, calls for associating individual centers in large groups, which would cooperate in completing research projects, which currently are being implemented in Europe. Novel treatment modalities should improve the treatment results in the high risk group, as well as decrease the late side-effects number in all children treated for neuroblastoma.

Age Factors↗

PubMed2001

Large cell/anaplastic medulloblastomas and medullomyoblastomas: clinicopathological and genetic features.

OBJECT: Medulloblastoma is the most common malignant central nervous system neoplasm found in children. A distinct variant designated large cell/anaplastic (LC/A) medulloblastoma is characterized by frequent dissemination of cerebrospinal fluid (CSF) at presentation and a more aggressive clinical course. The authors report on their examination of the clinicopathological and genetic features of seven such cases encountered at their institution. METHODS: Eighty cases of medulloblastomas were reviewed and seven (8.8%) of these were believed to fit the histological and immunohistochemical criteria for LC/A medulloblastoma. In three cases (43%) either desmoplastic or classic medulloblastoma was the underlying subtype, and in two cases (28%) the LC/A tumor was found within the setting of medullomyoblastoma. Fluorescence in situ hybridization was used in six of the seven cases to characterize the presence of isochromosome 17q, deletion of chromosome 22q (a deletion characteristically found in atypical teratoid/rhabdoid tumors), and c-myc amplification. The patients' clinical histories revealed CSF dissemination in all cases and lymph node metastasis in one case. Isochromosome 17q was found in five (83%) of six cases. Evidence of chromosomal gains indicated aneuploidy in three tumors (50%), and amplification of c-myc was found in three tumors (50%). No 22q deletions were encountered. CONCLUSIONS: A high percentage of LC/A medulloblastomas arise within a background of typical medulloblastomas or medullomyoblastomas. As is the case in conventional medulloblastomas, the presence of 17q is a common early tumorigenic event; however, in a significant percentage of specimens there is also evidence of aneuploidy and/or amplification of c-myc. These findings indicate that LC/A morphological characteristics reflect a more advanced tumor stage than that found in pure medulloblastomas or in typical medullomyoblastomas.

Adolescent↗

PubMed1995

Problems of neuroblastoma screening for 6 month olds and results of second screening for 18 month olds.

Nationwide neuroblastoma mass screening for 6-month-old infants (first screening) was introduced in Japan in 1985. About 110 neuroblastoma cases are detected annually by the first screening and treated, with a survival rate of 97%. Sensitivity of the first screening (positive cases/positive cases+false negative cases) is about 75%, and the prognosis of false-negative cases is unfavorable. A second screening at 18 months of age was started to rescue false-negative cases in Miyagi Prefecture in May 1992. Of 62 neuroblastoma cases treated in our hospital since 1985, 40 cases had received the first screening. Twenty cases were positive at first screening, 18 cases were false negative, and 2 cases were false negative and picked up by the second screening. Age distribution of false-negative cases ranged from 12 to 83 months and included 12 cases younger than 36 months old. Only 5 of 18 false-negative cases are alive without the disease. From May 1992 to November 1993, 14,282 infants had received the second screening (compliance rate: about 75%), and 2 neuroblastoma cases were detected. The first case was stage III with paraortic lymph node metastases, Shimada UH, aneuploidy and negative N-myc amplification. The second case was stage II with Shimada FH, aneuploidy, and negative N-myc amplification. Both cases are alive now without the disease after undergoing radical operation and chemotherapy. The first screening is effective for early detection of neuroblastoma cases, but the sensitivity is insufficient; the authors recommend a second screening to rescue false-negative cases.

Adrenal Gland Neoplasms↗

PubMed2004

Double minute chromosomes in monoblastic (M5) and myeloblastic (M2) acute myeloid leukemia: two case reports and a review of literature.

Double minutes (dmin) are small, paired chromatin bodies that lack a centromere and represent a form of extrachromosomal gene amplification. Although they have been found in a variety of solid tumors, their presence in hematological malignancies, especially acute myeloid leukemia (AML), is rare. In addition, the presence of dmin may be a mechanism for upregulated oncogene expression and is generally associated with a poor prognosis. We describe two patients who had dmin at initial presentation of AML, including the first case of M5a with C-MYC amplification on dmin, and another case with C-MYC amplification as the only cytogenetic finding. We review here a total of 33 cases with dmin in AML. C-MYC was amplified by the dmin in 25 cases, while other putative oncogenes were amplified in the other 8.

Adult↗

PubMed1994

Analysis of HPV-positive and -negative vulvar carcinomas for alterations in c-myc, Ha-, Ki-, and N-ras genes.

Mutation or overexpression of certain host genes, including c-myc, Ha-ras, and Ki-ras, have been associated with genital squamous neoplasia, specifically in the cervix, and have been implicated in the natural history of these tumors. The relationship of these host gene alterations to vulvar squamous cell carcinomas has not been previously studied. We analyzed archival material from 13 human papillomavirus-positive and -negative vulvar squamous cell carcinomas for mutations in Ha-, Ki-, and N-ras genes, and a smaller number of fresh samples for c-myc amplification, using PCR-based assays. For comparison, eight cervical squamous cell carcinomas (three fixed and five fresh) were also analyzed. Analysis for ras mutations revealed a previously reported silent allelic variant at nucleotide 1744 in the Ha-ras gene, but no mutations in codons 12, 13, or 61. Similarly, genomic amplification of c-myc beyond a maximum of three haploid copies was not identified in the cases. These findings indicate that alterations in myc or ras sequences are not linked to vulvar squamous cell carcinomas or to the presence or absence of HPV nucleic acids. Moreover, they apparently will not distinguish vulvar from cervical carcinomas, both groups appearing to be unlikely to harbor these sequence alterations.

Base Sequence↗

PubMed1994

How to deal with advanced cases of neuroblastoma detected by mass screening: a report from the Pediatric Oncology Study Group of the Kyushu area of Japan.

Since 1985, a nationwide program of mass screening (MS) for neuroblastoma has been underway for 6-month-old infants throughout Japan. As a result, the number of patients with stage I or II disease has obviously increased, and this has resulted in overall improvement of the prognosis for neuroblastoma. Some cases detected by MS were already in an advanced stage and have also had a good prognosis. In such cases, no definitive treatment protocol has been developed. Therefore, the authors investigated (1) the clinical and biological features of the advanced neuroblastoma cases detected by MS and (2) the best way to deal with such cases. The authors analyzed 94 cases of advanced-stage neuroblastoma registered in the Kyushu area (population, 15 million) between 1985 and 1990. Eighteen cases (16 stage III, 2 stage IV) were found by MS, and the others (23 stage III, 53 stage IV) were diagnosed clinically. The following results were obtained: (1) No N-myc amplifications were observed in cases detected by MS, whereas 16 of the 45 examined patients in the non-MS group had high amplifications of N-myc. (2) With regard to Shimada's classification, DNA content, and S-100 protein positivity, most of the advanced tumors found by MS showed characteristics indicating a good prognosis. (3) The 5-year survival rate for the non-MS group is less than 25%, whereas all of the patients whose tumors were detected by MS are alive, even after undergoing mild chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗

PubMed1995

Allelotype of neuroblastoma.

Although relatively high incidence of loss of heterozygosity (LOH) on chromosomes 1p, 11q, and 14q have been reported in neuroblastoma, it is still unclear whether or not LOH occurs specifically on these chromosome arms in neuroblastoma since only a few chromosomal arms have been examined for LOH in previous studies. Therefore, we screened 81 cases of tumors for LOH on all 22 autosomes and chromosome X using 35 restriction fragment length polymorphism markers and eight microsatellite markers. High incidence of LOH (> 20%) was observed on six chromosome arms; 1p (26%), 2q (30%), 9p (36%), 11q (24%), 14q (22%), and 18q (31%). Frequencies of LOH on other chromosome arms were less than 13%. Patients with 9p LOH in the tumors showed statistically significant association with advanced stage of the disease and poor prognosis (P = 0.037 and P = 0.003, respectively) independently from N-myc amplification, while LOH on other chromosomes did not show association with stage, prognosis, and N-myc amplification. Thus, besides LOH on chromosomes 1p, 11q, and 14q, LOH on chromosomes 2q, 9p, and 18q also occurs relatively frequently in neuroblastoma, indicating the involvement of multiple tumor suppressor genes in the development of neuroblastoma. It is possible that there is a novel tumor suppressor gene on chromosome 9p which is involved in the progression of neuroblastoma.

Alleles↗

PubMed2003

[The characteristics of mediastinal neuroblastoma and perspectives on surgical excision].

Thoracic (mediastinal) neuroblastomas (NB) have been reported to differ from abdominal (suprarenal and retroperitoneal) NB and to be associated with better prognosis. The comparison between them is rarely published. In this retrospective study, the characteristics of thoracic NB (17 cases) are investigated and compared with abdominal NB (51 cases). Regarding the diagnosis, thoracic NB presented in lower clinical stages I and II in 35.3% of cases, compared to 11.7% of abdominal NB in stages I and II (p<0.001). The disease was initially diagnosed at less than one year of age in 7/17 (41.2%) of thoracic NB and in 12/51 (23.5%) in abdominal cases (p<0.001). The median age at the time of initial diagnosis was 15.3 months for thoracic NB and 27.6 months for abdominal neuroblastoma (p<0.05). The cases with an elevated vanillylmandelic acid (VMA) and homovanyillic acid (HVA) excretion were 9/17 (52.9%) in the mediastinal NB, and 43/51 (84.3%) in the abdominal NB, respectively (p<0.05). The quantitative values of tumour markers were significantly lower in thoracic NB (0.85 vs. 2.14, p<0.001). Regarding surgery, complete tumour resection was achieved in 15/17 thoracic NB (88.2%) compared to 36/51 (70.6%) radicality in abdominal NB. Surgical complications developed in 5/17 thoracic procedures (29.4%) without a lethal outcome. The mean tumour mass of thoracic NB was 56.5 g vs. 106.3 g of abdominal neuroblastoma (p<0.001). The incidence of ganglioneuroblastoma in mediastinal tumours was 3/17 (17.6%) compared to 8/51 (15.7%) in abdominal NB (non significant). A favorable histology based on Shimada classification was found in 37% of the mediastinal neuroblastoma cases and in 22% in the abdominal NB cases (p<0.05). Regarding the biological properties, genetic malformations associated with NB were identified in 2 thoracic cases (1p deletion and polyploidy). Genetic changes were identified in 12 cases of abdominal NB (1p deletion in 4 cases, DNA ploidy in 6 cases, N-myc amplification in 1 case). One additional abdominal NB had 1p deletion, DNA ploidy and N-myc amplification. This study supports results of other investigations that thoracic NB differs significantly in many aspects from abdominal NB. Important differences in favorable histology and biological properties of thoracic NB have changed the concept of surgical treatment, although unnecessary attempts of surgical radicality still lead to serious complications. Complete excision remains the mainstay of therapy of localised thoracic NB, while in most abdominal tumours the aim of an initial operation should be sampling of tumour tissue for histology and molecular biological examination, with complete excision of the mass as the second priority.

Abdominal Neoplasms↗

PubMedDate not supplied

C-myc overexpression, c-mil, c-myb expression in a breast tumor cell line. Effects of estrogen and antiestrogen.

In breast tumor cell lines, c-myc amplification is frequently associated with estrogen unresponsiveness. We, however, succeeded in characterizing an estrogen-responsive cell line VHB1 derived from a duct cell carcinoma, which exhibits c-myc amplification and overexpression. We therefore studied the effects of estrogen and antiestrogen on c-myc expression in this particular cell line. We also investigated these effects on the expression of c-mil and c-myb oncogenes, also expressed but not amplified in VHB1 cells. Short-(1 h) and long-(72 h) term stimulations were performed. Our experiments showed that estradiol (E2 10(-8) M) was still able to stimulate c-myc expression equally either after short or long-term treatment. In the same way, the antiestrogen 4-hydroxytamoxifen equally decreased c-myc expression but the reversal effect of E2 after long-term antiestrogen treatment was more pronounced than after short-term treatment. The effects of E2 and 4-OH Tam on the expression of the not-amplified c-mil and c-myb oncogenes were stronger than those observed on c-myc expression; however, the E2 reversal effect was identical either after short or long-term antiestrogen treatment. Our results may enlighten some aspects of the complex action of some of the early- and late-growth regulated genes in breast cancer.

Blotting, Northern↗

PubMed1993

Preferential amplification of the paternal allele of the N-myc gene in human neuroblastomas.

Genomic imprinting plays a role in influencing the parental origin of genes involved in cancer-specific rearrangements. We have analysed 22 neuroblastomas with N-myc amplification to determine the parental origin of the amplified N-myc allele and the allele that is deleted from chromosome 1p. We analysed DNA from neuroblastoma patients and their parents, using four polymorphisms for 1p and three for the N-myc amplicon. We determined that the paternal allele of N-myc was preferentially amplified (12 out of 13 cases; P = 0.002). However, the paternal allele was lost from 1p in six out of ten cases, consistent with a random distribution (P > 0.2). These results suggest that parental imprinting influences which N-myc allele is amplified in neuroblastomas, but it does not appear to affect the 1p allele that is deleted in the cases that we have examined.

Adrenal Gland Neoplasms↗

PubMed2006

Fluorescence in situ hybridization assessment of c-myc gene amplification in breast tumor tissues.

This chapter details methods used for analysis of DNA copy-number changes in breast tumor tissues through the use of fluorescence in situ hybridization. The specific DNA probe described herein is the oncogene c-myc, although the tissue fluorescence in situ hybridization methodology presented is suitable for dual-color studies of most unique sequence and chromosome specific control probes. The breast tumor tissue sections are first deparaffinized in a solvent and clearing agent, and then pretreated with a protease to allow the target DNA within the breast tissue cells to be uncovered. This allows the DNA to be available for hybridization with the labeled c-myc probe. The tissue sections are then analyzed to assure that appropriate digestion of cellular material has been attained. The tissues are then denatured. The c-myc probe and control probe for the centromere of chromosome 8 are commercially available as differentially labeled and are cohybridized to the tissue and sealed beneath a cover slip in a humid chamber. They are incubated for 12-16 h. The cover slip is then removed, and the section is postwashed in 2X saline sodium citrate at 72 degrees C for 5 min and allowed to cool to room temperature in a detergent solution. The slides are then counterstained with 4',6-diamidino-2-phenylindole, and a cover slip is applied. The slides are then viewed with fluorescence microscopy using filters that allow the c-myc and chromosome 8 signals to be visualized. If possible, 50 cells are counted, and the data are expressed as number of c-myc signals/number of chromosome 8 signals.

Breast Neoplasms↗

PubMed1985

Evolution of karyotypic abnormalities and C-MYC oncogene amplification in human colonic carcinoma cell lines.

Cell lines (COLO 320 DM and COLO 320 HSR), established from a human neuroendocrine tumor, contain an amplified cellular oncogene (c-myc). We have previously shown that the homogeneously staining regions (HSRs) of a marker chromosome in the COLO 320 HSR cells that evolved in culture from COLO 320 DM cells contain amplified c-myc. Molecular hybridization in situ has now been used to demonstrate that the HSRs are on both arms of what was once an X chromosome. We also show that amplified c-myc copies are present in the isolated double minute chromosomes (DMs) of the COLO 320 DM cells that were characteristic of the tumor cells initially established from the patient. The results suggest that the amplified c-myc appeared first as DMs and was subsequently transposed to engender HSRs on an X chromosome. The initial COLO 320 tumor cell may have acquired two "early replicating" (i.e., active) X chromosomes and lost the "late replicating" (i.e., inactive) X.

Cell Line↗

PubMed2001

Evaluation of myc and chromosome 8 copy number in colorectal cancer using interphase cytogenetics.

To reveal the significance of genetic abnormalities of the c-myc gene, 56 colorectal tumors (43 colorectal carcinomas, 5 recurrent or metastatic tumors, and 8 adenomatous polyps) were analyzed using fluorescence in situ hybridization (FISH). Two probes specific for c-myc and the chromosome 8 centromere were used for dual color FISH. In each case, 100-200 nuclei were observed for signals from the probes. The percent of nuclei with c-myc amplification (PMA) was defined as the proportion of nuclei representing the ratio of c-myc/chromosome 8 >1.0, and the percent of nuclei with the greater number of c-myc (PGNM) was defined as the proportion of nuclei representing the ratio of c-myc/chromosome 8 > or =2.0. Low level amplification was defined as a case with PMA > or =10% and PGNM <10%. High level amplification was defined as a case with PGNM > or =10%. While adenomatous polyps and in situ carcinomas showed no c-myc amplification, the low level amplification and high level amplification of c-myc were observed in 48.8% (21/43) and 20.9% (9/43) of primary colorectal carcinomas. In addition, the group including cases of stage IIIb and IV exhibited significantly higher average copy numbers of c-myc (CN-myc), PMA and PGNM than the other group of earlier stages. FISH was thought a useful cytogenetic method to detect genetic abnormalities in solid tumors. It was shown that the c-myc gene amplification identified using FISH was associated with the aggressiveness of colorectal carcinoma.

Adult↗

PubMed1997

Detection of chromosomal anomalies and c-myc gene amplification in the cribriform pattern of prostatic intraepithelial neoplasia and carcinoma by fluorescence in situ hybridization.

Grading of the cribriform pattern of prostate cancer is controversial, and the genetic changes are largely unknown. Furthermore, the pathogenetic relationship between the cribriform pattern of high-grade prostatic intraepithelial neoplasia (PIN) and cribriform carcinoma is poorly understood. We used fluorescence in situ hybridization with centromere-specific probes for chromosomes 7, 8, 10, 12, and Y and a region-specific probe for c-myc to evaluate genetic changes in matched foci of high-grade PIN (48 foci) and prostatic carcinoma (71 foci) in 25 whole-mount radical prostatectomy specimens from patients with metastatic cancer. These cases included 10 foci of cribriform PIN and 10 foci of cribriform cancer. Numeric chromosomal anomalies were found in 67 and 68% of the high-grade PIN and carcinoma foci, respectively. Extra copies of the c-myc gene were identified in 52 and 44% of the high-grade PIN and carcinoma foci, respectively. The cribriform pattern of cancer had a higher percentage of foci with gain of chromosomes 7, 12, and Y, loss of chromosome 8, and extra copies of c-myc gene than other Gleason Primary Patterns 3 and 4; there was no difference, however, for all paired comparisons of genetic changes between the cribriform pattern of cancer and Gleason Primary Pattern 5 cancer. Cribriform PIN and cribriform cancer generally exhibited similar anomalies, although the percentage of foci with gain of chromosomes 10 and 12 was higher in cribriform cancer. Our results indicate that the cribriform pattern of prostate cancer shares genetic changes with Gleason Primary Pattern 5 and that both contain more genetic changes than the cribriform pattern of PIN. These findings suggest that the cribriform pattern of prostate cancer has biologic similarity with Gleason Pattern 5 carcinoma and that the cribriform pattern of PIN is closely associated with the cribriform pattern of prostatic carcinoma.

Adenocarcinoma↗

PubMed2006

T-cell prolymphocytic leukemia: an aggressive T cell malignancy with frequent cutaneous tropism.

BACKGROUND: T-cell prolymphocytic leukemia (T-PLL), formerly categorized as T-cell chronic lymphocytic leukemia, is a rare and aggressive hematologic malignancy. Although the skin is characteristically involved, it is not a well-recognized entity in the dermatologic literature. METHODS: Six cases of cutaneous T-PLL are presented from a clinical, light microscopic, and phenotypic perspective. RESULTS: The patient population comprised 2 women and 4 men, with a mean age of 69.8 years. The disease was associated in all with skin involvement with facial preference; edema, purpura, and lesional symmetry were characteristic. The skin biopsies demonstrated a largely non-epidermotropic angiocentric lymphocytic infiltrate with accompanying hemorrhage. The cells showed irregular- to reniform-shaped nuclei with small nucleoli and eosinophilic rims of cytoplasm. Phenotypic studies revealed three prevailing profiles: CD4 dominant in 4, CD8 dominant in one, and co-expression of CD4 and CD8 in one. CD3 loss was seen in one case. All expressed T-cell leukemia 1 (TCL-1) and CD7; cutaneous lymphocyte antigen expression was discernible in a dot-like perinuclear array. All cases tested excluding one expressed TCL-1 and CD52. In two cases tested, T-cell receptor beta rearrangements were observed. Cytogenetic studies demonstrated a paracentromeric chromosome 14 inversion. Polysomy 8 and MYC amplification was seen in one case, manifesting an aggressive clinical course. Four patients died from their disease within 18 months of diagnosis. LIMITATIONS: Cytogenetic MYC amplification, FISH, and TCR beta studies were conducted on each of 2 cases, respectively, due to limitations of tissue block samples and/or peripheral blood. cMYC translocation studies were conducted on 3 of the 6 cases, again due to limitations imposed by the tissue samples on the cases. The last case was recently diagnosed and, therefore, long-term follow-up is not possible. CONCLUSION: T-PLL is a distinctive post-thymic T-cell malignancy with frequent cutaneous tropism. A diagnosis is possible in almost all cases based on characteristic clinical, light microscopic, phenotypic, and cytogenetic features. While a chromosome 14 inversion is highly characteristic, additional inherent cytogenetic differences, such as trisomy 8 with CMYC over-amplification, may account for some case to case variation in clinical course.

Aged↗