Application of The Paris System to atypical urine cytology samples: correlation with histology and UroVysion® FISH

OBJECTIVES

To evaluate whether atypical urine cytology cases may be stratified more objectively using The Paris System (TPS) and whether reclassified cases correlate with histology and UroVysion^® results.

METHODS

Atypical urine cytology cases subjected to UroVysion^® testing over a period of 6 years were reviewed. Each case was reclassified according to TPS and correlated with histology and UroVysion^® results.

RESULTS

A total of 91 cases were identified; 70.3% were reclassified as 'negative for high-grade urothelial carcinoma (HGUC)' and 14.3% as 'atypical urothelial cells (AUC)'. The histological correlation was available in 45 cases. In the 'negative for HGUC' category, 67.9% had no histological evidence of malignancy, but 17.9% were diagnosed as HGUC. In the 'AUC' category, histology revealed urothelial carcinoma in 70% of the cases (of these, 71.4% were high grade). There was no histological evidence of malignancy in 30% of cases; notably, all of which were from patients under surveillance. The sensitivity and specificity of UroVysion^® were 85.7% and 33.3% in the 'AUC' group and 62.5% and 100% in the 'negative for HGUC' group.

CONCLUSIONS

The Paris System is an objective template for reporting urine cytology specimens, and is particularly useful in identifying HGUC cases and refining the category of 'AUC'.

Autoimmune cytopenias in the 22q11.2 deletion syndrome

We describe two cases of recurrent autoimmune cytopenias, which were subsequently diagnosed with a 22q11.2 deletion/DiGeorge syndrome. The cases are of particular interest as both possessed limited clinical features of this syndrome, and the investigation of haematological abnormalities led to the establishment of a definitive genetic diagnosis.

Identification and molecular characterisation of a CALM-AF10 fusion in acute megakaryoblastic leukaemia

The t(10;11)(p13;q14-21) is a non-random translocation described in acute lymphoblastic and myeloid leukaemias. It results in the fusion of the gene CALM, which encodes a clathrin assembly protein, on 11q14 to the gene AF10, a putative transcription factor on 10p13. Here we describe for the first time, the occurrence of a CALM-AF10 fusion in a case of acute megakaryoblastic leukaemia. Fluorescence in situ hybridisation and reverse transcriptase polymerase chain reaction were used to confirm the presence of a CALM-AF10 fusion. A novel splice variant of CALM missing nt 1927-2091 was also detected. Though CALM is a cytoplasmic protein, the chimaeric fusion product is able to localise to both the nucleus and cytoplasm. Analysis of the fusion variants suggests, however, that the critical fusion product is likely to be cytoplasmic and contain the interactive leucine zipper of AF10.

Cytogenetic and molecular evidence of marrow involvement in extramedullary acute myeloid leukaemia

A diagnosis of granulocytic sarcoma was made in a 2-year-old child based on the detection of myelomonocytic blasts in tissue obtained from a subcutaneous nodule with no evidence of concomitant disease in the bone marrow. The child responded to systemic chemotherapy and is in remission 3 years later. An identical clone with an in frame fusion of the MLL and AF10 genes was identified from both tissue and bone marrow samples. The generation of an in frame MLL-AF10 fusion requires complex intra- and interchromosomal exchanges between chromosomes 10 and 11. In this case, an intrachromosomal rearrangement of chromosome 5 was also observed. This case illustrates the presence of systemic disease in extramedullary leukaemia, its response to systemic rather than topical therapy and suggests that the events leading to chromosomal translocations in leukaemia may be part of a generalized intracellular event.

Characterization of acute promyelocytic leukemia cases lacking the classic t(15;17): results of the European Working Party. Groupe Français de Cytogénétique Hématologique, Groupe de Français d'Hematologie Cellulaire, UK Cancer Cytogenetics Group and BIOMED 1 European Community-Concerted Action "Molecular Cytogenetic Diagnosis in Haematological Malignancies"

Acute promyelocytic leukemia (APL) is typified by the t(15;17), generating the PML-RAR alpha fusion and predicting a beneficial response to retinoids. However, a sizeable minority of APL cases lack the classic t(15;17), prompting the establishment of the European Working Party to further characterize this group. Such cases were referred to a workshop held in Monza, Italy and subjected to morphologic, cytogenetic, and molecular review, yielding 60 evaluable patients. In the majority (42 of 60), molecular analyses revealed underlying PML/RAR alpha rearrangements due to insertions (28 of 42) or more complex mechanisms, including 3-way and simple variant translocations (14 of 42). Metaphase fluorescence in situ hybridization (FISH) demonstrated that insertions most commonly led to formation of the PML-RAR alpha fusion gene on 15q. In 11 of 60 workshop patients, PLZF/RAR alpha rearrangements were identified, including 2 patients lacking the t(11;17)(q23;q21). In one case with a normal karyotype, FISH analysis revealed insertion of RAR alpha into 11q23, and PLZF-RAR alpha was the sole fusion gene formed. Two patients were found to have t(5;17), one with a diffuse nuclear NPM staining pattern and with NPM-RAR alpha and RAR alpha-NPM transcripts detected. In the other with an unbalanced der(5)t(5;17)(q13;q21) and a nucleolar NPM localization pattern, an NPM/RAR alpha rearrangement was excluded, and FISH revealed deletion of one RAR alpha allele. In the remaining 5 workshop patients, no evidence was found for a rearrangement of RAR alpha, indicating that in rare instances, alternative mechanisms could mediate the differentiation block that typifies this disease. This study highlights the importance of combining morphologic, cytogenetic, and molecular analyses for optimal management of APL patients and better understanding of the pathogenesis of the disease. (Blood. 2000;96:1297-1308)

Therapy-related myelodysplasia and secondary acute myelogenous leukemia after high-dose therapy with autologous hematopoietic progenitor-cell support for lymphoid malignancies

PURPOSE

To evaluate the incidence of and risk factors for therapy-related myelodysplasia (tMDS) and secondary acute myelogenous leukemia (sAML), after high-dose therapy (HDT) with autologous bone marrow or peripheral-blood progenitor-cell support, in patients with non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Between January 1985 and November 1996, 230 patients underwent HDT comprising cyclophosphamide therapy and total-body irradiation, with autologous hematopoietic progenitor-cell support, as consolidation of remission. With a median follow-up of 6 years, 27 (12%) developed tMDS or sAML.

RESULTS

Median time to development of tMDS or sAML was 4.4 years (range, 11 months to 8.8 years) after HDT. Karyotyping (performed in 24 cases) at diagnosis of tMDS or sAML revealed complex karyotypes in 18 patients. Seventeen patients had monosomy 5/5q-, 15 had -7/7q-, seven had -18/18q-, seven had -13/13q-, and four had -20/20q-. Twenty-one patients died from complications of tMDS or sAML or treatment for tMDS or sAML, at a median of 10 months (range, 0 to 26 months). Sixteen died without evidence of recurrent lymphoma. Six patients were alive at a median follow-up of 6 months (range, 2 to 22 months) after diagnosis of tMDS or sAML. On multivariate analysis, prior fludarabine therapy (P =.009) and older age (P =.02) were associated with the development of tMDS or sAML. Increased interval from diagnosis to HDT and bone marrow involvement at diagnosis were of borderline significance (P =.05 and.07, respectively).

CONCLUSION

tMDS and sAML are serious complications of HDT for NHL and are associated with very poor prognosis. Alternative strategies for reducing their incidence and for treatment are needed.

A new recurrent translocation, t(5;11)(q35;p15.5), associated with del(5q) in childhood acute myeloid leukemia. The UK Cancer Cytogenetics Group (UKCCG)

Partial deletion of the long arm of chromosome 5, del(5q), is the cytogenetic hallmark of the 5q-syndrome, a distinct subtype of myelodysplastic syndrome-refractory anemia (MDS-RA). Deletions of 5q also occur in the full spectrum of other de novo and therapy-related MDS and acute myeloid leukemia (AML) types, most often in association with other chromosome abnormalities. However, the loss of genetic material from 5q is believed to be of primary importance in the pathogenesis of all del(5q) disorders. In the present study, we performed fluorescence in situ hybridization (FISH) studies using a chromosome 5-specific whole chromosome painting probe and a 5q subtelomeric probe to determine the incidence of cryptic translocations. We studied archival fixed chromosome suspensions from 36 patients with myeloid disorders (predominantly MDS and AML) and del(5q) as the sole abnormality. In 3 AML patients studied, this identified a translocation of 5q subtelomeric sequences from the del(5q) to the short arm of an apparently normal chromosome 11. FISH with chromosome 11-specific subtelomeric probes confirmed the presence of 11p on the shortened 5q. Further FISH mapping confirmed that the 5q and 11p translocation breakpoints were the same in all 3 cases, between the nucleophosmin (NPM1) and fms-related tyrosine kinase 4 (FLT4) genes on 5q35 and the Harvey ras-1-related gene complex (HRC) and the radixin pseudogene (RDPX1) on 11p15.5. Importantly, all 3 patients with the cryptic t(5;11) were children: a total of 3 of 4 AML children studied. Two were classified as AML-M2 and the third was classified as M4. All 3 responded poorly to treatment and had short survival times, ranging from 10 to 18 months. Although del(5q) is rare in childhood AML, this study indicates that, within this subgroup, the incidence of cryptic t(5;11) may be high. It is significant that none of the 24 MDS patients studied, including 11 confirmed as having 5q-syndrome, had the translocation. Therefore, this appears to be a new nonrandom chromosomal translocation, specifically associated with childhood AML with a differentiated blast cell phenotype and the presence of a del(5q).

Immunochemical evaluation of the organ specificity of prostatic acid phosphatase

In a survey of normal and cancerous human tissues we determined the distribution of immunoreactive prostatic acid phosphatase, using rabbit antiserum to acid phosphatase purified from prostatic fluid. In all normal tissues and blood cells studied except leukocytes we found less than 0.1% (expressed as micrograms per gram of wet weight of tissue) of the quantity of immunoreactive prostatic acid phosphatase detected in normal prostate tissue by radioimmunoassay. A small quantity of cross-reactive antigen (2.5 microgram/10(8) cells) was found in leukocytes. In all normal and cancerous nonprostate tissues surveyed by an immunohistochemical technique we detected no immunoreactive prostatic acid phosphatase, except in kidney tissue. Faint but reproducible staining was detected in the lumen of distal tubules and collecting ducts and within interstitial capillaries. Immunoreactive prostatic acid phosphatase was detected in the urine of pre- and post-pubertal males and females. We propose that this material is from serum (low concentrations of immunoreactive prostatic acid phosphatase are present in the serum of men and women) and that it is excreted into urine by the kidneys. Full proof of this must await future experimentation. The specificity of our antiserum for prostatic acid phosphatase was demonstrated by the fact that the Mr 100 000 and 20 000 liver acid phosphatase isoenzymes did not cross with our antiserum in either the radioimmunoassay or double-diffusion analysis. Similarly, preparations of isoenzymes 5A and 5B are human serum albumin did not cross react.

Immunochemical evaluation of the organ specificity of prostatic acid phosphatase

In a survey of normal and cancerous human tissues we determined the distribution of immunoreactive prostatic acid phosphatase, using rabbit antiserum to acid phosphatase purified from prostatic fluid. In all normal tissues and blood cells studied except leukocytes we found less than 0.1% (expressed as micrograms per gram of wet weight of tissue) of the quantity of immunoreactive prostatic acid phosphatase detected in normal prostate tissue by radioimmunoassay. A small quantity of cross-reactive antigen (2.5 microgram/10(8) cells) was found in leukocytes. In all normal and cancerous nonprostate tissues surveyed by an immunohistochemical technique we detected no immunoreactive prostatic acid phosphatase, except in kidney tissue. Faint but reproducible staining was detected in the lumen of distal tubules and collecting ducts and within interstitial capillaries. Immunoreactive prostatic acid phosphatase was detected in the urine of pre- and post-pubertal males and females. We propose that this material is from serum (low concentrations of immunoreactive prostatic acid phosphatase are present in the serum of men and women) and that it is excreted into urine by the kidneys. Full proof of this must await future experimentation. The specificity of our antiserum for prostatic acid phosphatase was demonstrated by the fact that the Mr 100 000 and 20 000 liver acid phosphatase isoenzymes did not cross with our antiserum in either the radioimmunoassay or double-diffusion analysis. Similarly, preparations of isoenzymes 5A and 5B are human serum albumin did not cross react.