Digital image analysis agrees with visual estimates of adult bone marrow trephine biopsy cellularity.

INTRODUCTION: Evaluation of cellularity is an essential component of bone marrow trephine biopsy examination. The standard practice is to report the results as visual estimates (VE). Digital image analysis (DIA) offers the promise of more objective measurements of cellularity. METHODS: Adult bone marrow trephine biopsy sections were assessed for cellularity by VE. Sections were scanned using an Aperio AT2 Scanscope and analyzed using a Cytonuclear (version 1.4) algorithm on halo software. Intraclass correlation (ICC) was used to assess relatedness between VE and DIA, and between MRI and DIA for a separate subset of patients. Trephine biopsy sections from a subset of patients with bone marrow biopsies uninvolved by malignancy were assessed for age-related changes. RESULTS: Interobserver VE agreement was good to excellent. The ICC value was 0.81 for VE and DIA, and 0.50 for MRI and DIA. Linearity studies showed no statistically significant trend for age-related changes in cellularity in our cohort (r = -.29, P = .06). CONCLUSIONS: Agreement was good between VE and DIA. It may be possible to use DIA or VE to measure cellularity in the appropriate clinical scenario. The limited sample size precludes similar determinations for MRI calculations. Further studies examining healthy donors are necessary before making definitive conclusions regarding age and cellularity.

ICSH guidelines for the standardization of bone marrow immunohistochemistry.

Bone marrow (BM) tissue biopsy evaluation, including trephine biopsy and clot section, is an integral part of BM investigation and is often followed by ancillary studies, in particular immunohistochemistry (IHC). IHC provides in situ coupling of morphological assessment and immunophenotype. The number of different IHC tests that can be applied to BM trephine biopsies and the number of indications for IHC testing is increasing concurrently with the development of flow cytometry and molecular diagnostic methods. An international Working Party for the Standardization of Bone Marrow IHC was formed by the International Council for Standardization in Hematology (ICSH) to prepare a set of guidelines for the standardization of BM IHC based on currently available published evidence and modern understanding of quality assurance principles as applied to IHC in general. The guidelines were discussed at the ICSH General Assemblies and reviewed by an international panel of experts to achieve further consensus and represent further development of the previously published ICSH guidelines for the standardization of BM specimens handling and reports.

Aplastic anemia secondary to azathioprine in systemic lupus erythematosus: report of a case with normal thiopurine S-methyltransferase enzyme activity and review of the literature.

Azathioprine-induced aplastic anemia and fatal myelosuppression is a rare occurrence in patients with systemic lupus erythematosus (SLE). We report a case of a 53-year-old female with a normal thiopurine S-methyltransferase (TPMT) level who developed aplastic anemia within 4 weeks of azathioprine initiation, resulting in death. Physicians should be vigilant in monitoring routine blood work when administering azathioprine, a relatively common drug, in patients with SLE.

beta-Catenin expression in thyroid follicular lesions: potential role in nuclear envelope changes in papillary carcinomas.

The morphologic distinction of benign and malignant thyroid follicular lesions can sometimes be challenging, therefore an immunohistochemical marker to aid in this distinction would be useful. beta-Catenin is one such potential marker. It is part of a membrane-bound cell growth-signaling complex that plays a role in cell adhesion, as well as in promotion of growth through activation of the Wnt signaling pathway. Oncogenic signaling occurs when beta-catenin is released, accumulates in the cytoplasm, translocates into the nucleus, and promotes transcription of genes including bcl-1 (cyclin D1) and c-myc that induce cell proliferation. Paraffin blocks from 133 thyroidectomy specimens were stained with monoclonal antibodies reactive with beta-catenin and cyclin D1. These included 53 cases of papillary thyroid carcinoma (PTC), 46 cases of follicular variant of papillary carcinoma (FVPC), 10 cases of follicular carcinoma (FC), and 24 cases of follicular adenoma (FA). Tissue from six normal thyroid specimens served as a control. The malignant lesions (PTC, FC, and FVPC) expressed strong cytoplasmic/nuclear staining and minimal residual membranous staining in 87%, 80%, and 71% of cases, respectively. In contrast, all normal thyroid tissue and 79% of FAs showed strong membranous reactivity with very minimal cytoplasmic staining. Interestingly, in 83% of PTC cases and 20% FVPCs, the intranuclear inclusions were distinctly beta-catenin positive. Cyclin D1 over expression correlated with cytoplasmic relocalization of beta-catenin in almost all cases, and no evidence of cyclin D1 gene amplification was observed. beta-Catenin can be of a diagnostic utility for thyroid lesions, because it highlights intranuclear inclusions in PTC, and shifts from a membranous localization to a cytoplasmic localization in malignant lesions. We speculate that the localization of beta-catenin in intranuclear inclusions may reflect a cytoskeletal remodeling activity of beta-catenin that is functionally significant for the PTC pathway.

Reduced risk of synovial sarcoma in females: X-chromosome inactivation?

Synovial sarcoma shows a characteristic t(X;18) translocation but not the expected female predominance in incidence. We speculate that, among females, one X-chromosome is inactivated and that only the translocation to an active X-chromosome leads to development of synovial sarcoma. Population-based cancer registry data from the SEER program support this hypothesis.

Clinical, immunologic, and pathologic correlates of bone marrow involvement in 291 patients with acquired immunodeficiency syndrome-related lymphoma.

Bone marrow involvement is reported in approximately 25% of patients with newly diagnosed acquired immunodeficiency syndrome-related lymphoma (ARL). Studied were 291 patients with ARL, diagnosed and treated at one medical center between 1984 and 1998. Clinical, immunologic, and pathologic characteristics of patients with bone marrow involvement were compared with those of patients without marrow involvement. Bone marrow involvement was present in 55 patients (19%). Small noncleaved lymphoma was diagnosed in 38% of the entire group and was the most common pathologic subtype in patients with bone marrow involvement (55% versus 34%; P =.008). Analysis of complete blood counts revealed a median hemoglobin level of 10.6 g/dL in both marrow-positive and marrow-negative groups. In contrast, a platelet count lower than 100 000/microL was more common in patients with bone marrow involvement (27% versus 11%; P =.02). Patients with marrow involvement were more likely to have leptomeningeal (cerebrospinal fluid [CSF]) lymphoma than patients whose marrows were uninvolved (24% versus 7%; P <.001) and were also more likely to have high lactate dehydrogenase (LDH) (P =.002), bone involvement (P <.001), and/or systemic B symptoms including fever, night sweats, and/or weight loss (P =.05). Median survival did not differ between marrow-positive and marrow-negative groups. On multivariate analysis, factors associated with decreased survival of marrow-positive patients included greater than 50% involvement (P =.002), systemic B symptoms (P =.008), and high-grade histologic type (P =.035). Marrow involvement in ARL correlates with small noncleaved pathology, thrombocytopenia lower than 100 000 mm(3), high LDH, and lymphomatous involvement of the CSF. Survival is statistically shorter in patients with greater than 50% marrow involvement, high-grade pathology, and/or systemic B symptoms.

Immunohistochemical expression of cell cycle proteins E2F-1, Cdk-2, Cyclin E, p27(kip1), and Ki-67 in normal placenta and gestational trophoblastic disease.

The role of cell cycle protein expression in gestational trophoblastic disease is poorly understood. In this study we investigated the immunostaining patterns of G(1) restriction point and G(1)-S regulatory proteins E2F-1, Cdk2, cyclin E, p27(kip1), and the proliferation marker Ki-67 on routinely processed sections of 29 hydatidiform moles (10 partial moles and 19 complete moles, including 9 persistent moles), 7 choriocarcinomas, and 7 normal placentas. Ki-67 trophoblast staining decreased with increasing gestational age of the placenta, and showed maximal expression in gestational trophoblastic disease. Cyclin-dependent kinase activity, as reflected by Cdk2 expression patterns, also decreased with placental maturation. E2F-1 was uniquely expressed by trophoblasts of moles and choriocarcinoma. Cyclin E was maximally expressed by complete moles and choriocarcinomas, and showed an inverse relationship with the cyclin-dependent kinase inhibitor p27(kip1). Abnormal trophoblastic proliferations may be mediated through interactions of Cdk-2, E2F-1, cyclin E, and p27(kip1). Overexpression of cyclin E was associated with more aggressive forms of gestational trophoblastic disease. However, we did not find distinguishing features between complete moles that spontaneously resolved after evacuation and persistent moles that required chemotherapy. The different expression patterns of cyclin E and E2F-1 in partial and complete moles may be useful in distinguishing these two entities. Furthermore, loss of p27(kip1) in malignant trophoblast may represent a necessary step in the development of choriocarcinoma.

Hyperplasia of mantle/marginal zone B cells with clear cytoplasm in peripheral lymph nodes. A clinicopathologic study of 35 cases.

We describe 35 peripheral lymph nodes classified as mantle cell/marginal zone B-cell hyperplasia with clear cells using morphologic and immunologic findings. For the purpose of this study, we obtained clinical follow-up information and performed immunoglobulin gene rearrangement studies on paraffin sections by polymerase chain reaction. Architecturally, the nodes were suggestive of a benign process: no pericapsular infiltration, sinuses readily identified, scattered reactive follicles present, and paracortical nodular hyperplasia present. No monocytoid B cells were present. Focally, small lymphoid cells with round nuclei and clear cytoplasm (clear cells) formed monomorphic nodular, inverse follicular, and/or marginal zone patterns. Flow cytometry and immunohistochemical analysis revealed neither light chain restriction nor an aberrant B-cell phenotype. Immunoglobulin gene rearrangement studies showed a clonal band in 1 of 26 cases in which DNA was amplified. To ascertain the clinical relevance of this positive case, follow-up information was obtained 30 months after the initial biopsy; the 83-year-old woman was alive without treatment but had splenomegaly and bone marrow involvement by marginal zone B-cell lymphoma. The morphologic and immunologic criteria used for diagnosis of mantle cell/marginal zone B-cell hyperplasia with clear cytoplasm are valid; however, to rule out the possibility of occult lymphoma, immunoglobulin gene rearrangement studies and clinical follow-up are necessary.

DNA topoisomerase IIalpha in multiple myeloma: a marker of cell proliferation and not drug resistance.

DNA topoisomerase IIalpha (topo IIalpha) is the target for a number of antineoplastic agents. Down-regulation of this enzyme is one form of drug resistance. Topo IIalpha is also involved in DNA replication and transcription and serves as an indicator of proliferation rate in many human malignancies. This study examines whether topo IIalpha is one of the mechanisms of chemoresistance commonly observed in multiple myeloma (MM) or alternatively, whether topo IIalpha is associated with tumor cell proliferation. Bone marrow (BM) biopsy sections from 72 cases of MM, stratified according to proliferative activity (bromodeoxyuridine uptake), were immunostained for topo IIalpha. Immunoreactivity with an additional marker of drug resistance, glutathione-S-transferase pi, and the proliferation marker Ki-67 were also examined. Topo IIalpha was expressed in 26 (36%) cases and correlated strongly with proliferative activity (P <.001). A role for drug resistance could not be supported, given this strong relationship with proliferation and the finding that glutathione-S-transferase pi expression in 57 (78%) cases was independent of topo IIalpha immunoreactivity. Topo IIalpha was identified in 91 to 100% of highly proliferative tumors, as evaluated by bromodeoxyuridine uptake or Ki-67 reactivity, respectively. Proliferation also correlated with the histologic grade of the MM. Therefore, topo IIalpha immunoreactivity is primarily a marker of cell proliferation in MM and as such is likely to have prognostic significance. Highly proliferative tumors are most likely to be sensitive to chemotherapeutic protocols using anti-topo IIalpha agents.

Pathology of autoimmune myelofibrosis. A report of three cases and a review of the literature.

We identified 3 patients with autoimmune myelofibrosis (AM) lacking American Rheumatism Association criteria for systemic lupus erythematosus (SLE). They had 1 or 2 cytopenias and lacked serologic evidence for SLE. Autoimmune features included psoriatic arthritis and positive direct Coombs test (DCT) result, DCT-positive autoimmune hemolytic anemia, and synovitis with polyclonal hypergammaglobulinemia. Bone marrow biopsy specimens from each patient were evaluated by routine morphologic and immunohistochemical examination. They demonstrated marked hypercellularity (2 cases) or hypocellularity (1 case), moderate erythroid hyperplasia (all cases) with left-shifted maturation (2 cases), intrasinusoidal hematopoiesis (all cases), slightly to moderately increased megakaryocytes (2 cases), and grade 3 to 4 reticulin fibrosis (all cases). All lacked basophilia, eosinophilia, bizarre megakaryocytes, clusters of megakaryocytes, and osteosclerosis. Mild to moderate bone marrow lymphocytosis was noted in all cases. In 2 cases, increased small T cells and B cells formed nonparatrabecular, loose aggregates. AM is a clinicopathologic entity that may lack features of SLE. Loose aggregates of bone marrow T and B lymphocytes and the absence of morphologic and clinical features of myeloproliferative disease or low-grade lymphoproliferative disease are clues that distinguish AM from better known causes of bone marrow fibrosis.

Cyclin D1 and E2F-1 immunoreactivity in bone marrow biopsy specimens of multiple myeloma: relationship to proliferative activity, cytogenetic abnormalities and DNA ploidy.

Cyclin D1, encoded by the CCND1 gene, is immunohistochemically detectable in up to one-third of cases of multiple myeloma (MM). To examine the mechanism of cyclin D1 overexpression, we compared cyclin D1 immunoreactivity with the results of conventional cytogenetics to determine if the t(11;14)(q13;q32) or other abnormalities of 11q11-14 explained cyclin D1 overexpression. Karyotypic abnormalities were found in 45 out of 67 (67%) MM cases; the t(11;14) was present in seven cases (10%). Additional 11q11-14 abnormalities were not identified. The t(11;14) correlated with cyclin D1 upregulation in low to intermediately proliferative MM, but was not present in highly proliferative tumours (assessed using bromodeoxyuridine labelling index). Cyclin D1 indirectly activates the transcription factor E2F-1. In the bone marrow biopsy specimens of MM cases, E2F-1 was concurrently expressed with cyclin D1 (P = 0.001), indicating that cyclin D1 is functional. However, as neither E2F-1 nor cyclin D1 expression correlated with proliferative activity, the speculation that t(11;14) upregulates the CCND1 gene to induce higher proliferation and possibly more aggressive disease is not supported. We conclude that in low to intermediately proliferative MM cases, cyclin D1 is probably upregulated by t(11;14), but an alternative mechanism is more probable in highly proliferative MM.

Cyclin D1 expression in dysplastic nevi: an immunohistochemical study.

OBJECTIVE: We previously surveyed cyclin D1 expression in common acquired nevi, Spitz nevi, and malignant melanomas and reported that benign nevi maintain a zonal pattern of cyclin D1 expression, in contrast with malignant melanomas. Our aim was to extend those observations by examining cyclin D1 expression in dysplastic nevi. METHODS: Cyclin D1 overexpression in 23 dysplastic nevi was detected by an immunohistochemical technique. The extent of atypia of the nevi was graded as mild, moderate, or severe, using previously established criteria. RESULTS: Cyclin D1 overexpression in dysplastic nevi maintained a zonal pattern, similar to Spitz nevi. Cyclin D1 overexpression was greatest in the region of the epidermal-dermal junction and was significantly less prominent in the papillary and reticular dermis, suggesting that cyclin D1 expression is under cell control and correlates with maturation of nevus cells. Cyclin D1 overexpression also correlated with cytologic atypia, as dysplastic nevi with moderate or severe cytologic atypia contained a greater percentage of cyclin D1-positive cells than did nevi with mild atypia. Six dysplastic nevi with many cyclin D1--positive cells were assessed by fluorescence in situ hybridization studies using cyclin D1--specific and chromosome 11 centromeric probes. In all cases, there was no evidence of 11q13 translocation, amplification, or trisomy of chromosome 11. CONCLUSIONS: Cyclin D1 may be involved in the pathogenesis of dysplastic nevi. Cyclin D1 overexpression does not appear to be explained by cyclin D1 locus amplification or translocation in most cases, and it may be a result of other cell abnormalities that up-regulate the protein level of cyclin D1.

Mast cell disease associated with acute myeloid leukemia: detection of a new c-kit mutation Asp816His.

Mast cell disease (MCD), a proliferation of mast cells (MC), is occasionally associated with hematologic malignancies. Neoplastic MC have activating c-kit mutations. c-kit is a receptor tyrosine kinase required for the development, proliferation, and survival of MC. Interaction of c-kit with its ligand stem cell factor induces dimerization, receptor phosphorylation, and signal transduction. The most common c-kit mutation detected in neoplastic MCD is Asp816Val, which results in ligand-independent autophosphorylation of the receptor leading to MC proliferation. We describe the rare occurrence of MCD associated with acute myeloid leukemia, report a novel c-kit mutation Asp816 His, and discuss the pathogenesis of MCD associated with hematologic malignancies.

Intravascular large B-cell lymphoma. A report of five cases initially diagnosed by bone marrow biopsy.

We report 5 cases of intravascular lymphoma (IVL) initially diagnosed by bone marrow aspiration and biopsy. Each patient had generalized symptoms; 1 also had neurologic deficits. CBC counts revealed anemia (4 patients), thrombocytopenia (4 patients), or mild leukopenia (1 patient). The bone marrow biopsy specimen was diagnostic in each case. Lymphoma cells were present in small groups or single file in sinusoids (in 1 patient, sinusoids were distended markedly by IVL) and were detected in bone marrow aspirate smears (4 patients) and peripheral blood smears (all patients). Immunohistochemical studies demonstrated that every neoplasm was of B-cell lineage, CD20+, positive for other B-cell antigens, and CD3- or CD43-. Immunophenotypic studies revealed at least 2, and possibly 3, distinct immunophenotypic groups of B-cell IVL: CD20+ CD5+ (3 neoplasms), CD20+ CD5- CD10+ (1 neoplasm), and CD20+ CD5- CD10 unknown (1 neoplasm). B-cell IVL may be detected by morphologic examination of peripheral blood and bone marrow, and involvement of these sites may be more common than is reported in the literature. Immunophenotypic studies are helpful in establishing the diagnosis and suggest that B-cell IVL is a heterogeneous group of neoplasms that may arise from more than 1 normal B-cell precursor.

Expression of cyclin D1 in parathyroid carcinomas, adenomas, and hyperplasias: a paraffin immunohistochemical study.

In this study, we assessed the frequency of cyclin D1 protein expression in normal and neoplastic parathyroid tissue (10 parathyroid carcinomas, 28 adenomas, 18 hyperplasias, and 32 normal parathyroid glands) with use of a monoclonal anticyclin D1 antibody and a heat-induced epitope retrieval method. Overexpression of cyclin D1 was identified in 10 (91%) of 11 biopsy specimens from 10 patients with parathyroid carcinomas and in 11 (39%) of 28 parathyroid adenomas. In addition, 11 (61%) of 18 cases of parathyroid hyperplasia also expressed cyclin D1 protein, an observation not reported previously. These results confirm the high frequency of cyclin D1 expression in parathyroid carcinomas and adenomas. In addition, the results of this study indicate that overexpression of cyclin D1 protein is not limited to neoplastic proliferations of parathyroid tissue but is also seen in non-neoplastic proliferations of parathyroid gland. Cyclin D1 protein expression was rarely (<6%) present in normal parathyroid tissue.

Cyclin D1 overexpression in Spitz nevi: an immunohistochemical study.

The morphologic distinction between Spitz nevus and malignant melanoma can be difficult. Because cyclin D1 has been reported to be overexpressed in malignant melanomas, but not in common acquired nevi, we hypothesized that cyclin D1 might be a useful marker to distinguish Spitz nevi from malignant melanoma. Thus, we assessed for cyclin D1 expression in 11 Spitz nevi (10 compound and 1 intradermal) and 9 malignant melanomas (4 Clark stages I-III and 5 Clark stages IV-V) using an immunohistochemical method and routinely fixed and processed tissues. The cyclin D1 results were arbitrarily divided into three groups: 0% to 10%, >10% to 25%, and >25%. We confirmed the observations reported previously by others that cyclin D1 is expressed in malignant melanomas but not in common acquired nevi. Unexpectedly, a relatively high number of cyclin D1-positive cells (i.e., >10%) was also found in all cases of Spitz nevus. However, unlike malignant melanoma, the cyclin D1 positivity in Spitz nevi was present in a zonal pattern. In other words, the number of cyclin D1-positive cells decreased as the lesion extended more deeply, with the number of positive cells in the reticular dermis being less than that in the papillary dermis. Fluorescence in situ hybridization methods were used to assess amplification of 11q13, the locus harboring the cyclin D1 gene, in four cases of Spitz nevus; all were disomic. Using the antibody MIB-1, we compared cyclin D1 expression to the proliferation rate in Spitz nevi. Despite the high cyclin D1 positivity, all Spitz nevi had a relatively low number of MIB-1-positive cells (mean=3.2%), which was significantly lower than that of malignant melanomas (mean=15.3%) (p < 0.001). Thus, unlike malignant melanoma, there appears to be a dissociation between cyclin D1 overexpression and cell proliferation in Spitz nevi.

Acute lymphoblastic leukemia. Survey of immunophenotype, French-American-British classification, frequency of myeloid antigen expression, and karyotypic abnormalities in 210 pediatric and adult cases.

Immunophenotypic studies are essential to distinguish acute lymphoblastic leukemia (ALL) from minimally differentiated acute myeloid leukemia (AMLM0) and to classify ALL into immunologic subtypes. Frequently, immunophenotyping identifies myeloid antigen expression in ALL, causing a potential diagnostic problem. To evaluate the immunophenotype of ALL, we studied 210 cases of pediatric and adult ALL by flow cytometry and compared the results with the French-American-British (FAB) Cooperative Group classification and the karyotypic findings. Myeloid-associated antigens were expressed in 78 (45.6%) of precursor B-cell ALL cases. Pediatric precursor B ALLs had a higher frequency of myeloid antigen expression than did adult cases. All mature B-cell ALL cases were negative for TdT and myeloid antigens. Myeloid antigen expression was less frequent in T-cell ALL cases compared with precursor B-cell ALL cases. Of the 192 cases submitted for cytogenetic analysis, 147 were abnormal. The most common chromosomal translocation was the Philadelphia chromosome, which was more likely to have L2 blast morphology and a precursor B immunophenotype. Myeloid antigen expression was present in 70.8% of Ph-positive cases (P = .008). Chromosome rearrangements involving 11q23 also showed an increased frequency of myeloid antigen expression. Chromosome translocations involving regions of T-cell receptor genes were present in 24% of T-cell ALL cases. A high percentage of ALL cases, however, had various other cytogenetic abnormalities, many of which involved less well-studied chromosomal regions.

Differential expression of cyclin D1 in breast papillary carcinomas and benign papillomas: an immunohistochemical study.

OBJECTIVES: Distinguishing intraductal papilloma from papillary carcinoma of the breast can be difficult using histologic criteria. Since cyclin D1, a G1 cell-cycle regulatory protein, is detectable immunohistochemically in a subset of breast carcinomas but not in benign breast tissues, we hypothesized that cyclin D1 immunoreactivity may be a marker for identifying papillary carcinoma. METHODS: Using an immunohistochemical method, we assessed for cyclin D1 expression in 8 breast papillomas and 6 papillary carcinomas, all of which were formalin fixed, routinely processed, and paraffin embedded. Cyclin D1 positivity also was compared with the overall proliferation rate, which was assessed by using the proliferation marker Ki-67. In each case, a 200-cell count was performed to obtain the percentage of cells positive for these 2 markers. RESULTS: The percentage of cyclin D1-positive cells was significantly higher in papillary carcinomas (89%+/-18%; range, 53%-98%) than in papillomas (8%+/-7%; range, 0%-19%). This difference was highly statistically significant (P < .0001). Although the difference in Ki-67 positivity between these 2 groups was also statistically significant (P = .01), separation of papillary carcinomas and papillomas by Ki-67 immunoreactivity was less clear because of overlapping values between groups: 13% +/-6%; range, 9% to 23% for papillary carcinomas versus 8%+/-2%; range, 6% to 12% for papillomas. CONCLUSIONS: These results support the notion that cyclin D1 is a useful marker for distinguishing breast papillomas from papillary carcinomas. The marker Ki-67 is also helpful, but is less useful than cyclin D1, owing to the overlap in Ki-67 results in papillomas and papillary carcinomas.

Untreated chronic lymphocytic leukemia concurrent with or followed by acute myelogenous leukemia or myelodysplastic syndrome. A report of five cases and review of the literature.

Although it has been known that patients with chronic lymphocytic leukemia (CLL) have a higher frequency of second malignant neoplasms, the development of acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS) in these patients is extremely rare. Most reported cases have been therapy-related. In this article, we report the clinical and immunophenotypic features of 5 cases of untreated CLL concurrent with or followed by the development of AML or MDS. All 5 patients were men, with ages ranging from 57 to 87 years (mean, 73.8 years). Four patients had AML and 1 patient had refractory anemia with ringed sideroblasts. In the 4 cases of AML and CLL, 2 distinct cell populations (i.e., myeloblasts and lymphocytes) were identified morphologically and/or immunophenotypically. Our findings support that this rare concurrence of AML or MDS and untreated CLL may represent 2 separate disease processes.

Using fluorescence-based human androgen receptor gene assay to analyze the clonality of microdissected dendritic cell tumors.

The clonality of dendritic cell proliferations arising in patients with previously diagnosed B-cell non-Hodgkin lymphoma has not been determined. The highly polymorphic human androgen receptor gene (HUMARA) can be used to assess the pattern of X-chromosome inactivation and, hence, the clonality of tumors in female patients. In this study, specimens from 2 female patients with dendritic cell tumor following low-grade B-cell non-Hodgkin lymphoma were analyzed. Microdissection was performed on tissue sections to obtain representative tissues for analysis. The HUMARA polymerase chain reaction was modified to include a fluorochrome (6-carboxyfluorescein)-labeled primer so the product could be assessed with the ABI Genescan Analysis program for the Macintosh (Applied Biosystems, Foster City, Calif). Our results indicate that dendritic cell proliferations associated with low-grade B-cell non-Hodgkin lymphoma are clonal lesions. Previous microdissection is very helpful in obtaining the desired cell populations for study. The use of a fluorescent primer coupled with the Genescan System is a novel, highly sensitive, quantitative system that avoids the use of radioactive materials.