Summary The bone marrow examination is an essential investigation for the diagnosis and management of many disorders of the blood and bone marrow. The aspirate and trephine biopsy specimens are complementary and when both are obtained, they provide a comprehensive evaluation of the bone marrow. The final interpretation requires the integration of peripheral blood, bone marrow aspirate and trephine biopsy findings, together with the results of supplementary tests such as immunophenotyping, cytogenetic analysis and molecular genetic studies as appropriate, in the context of clinical and other diagnostic findings. Methods for the preparation, processing and reporting of bone marrow aspirates and trephine biopsy specimens can vary considerably. These differences may result in inconsistencies in disease diagnosis or classification that may affect treatment and clinical outcomes. In recognition of the need for standardization in this area, an international Working Party for the Standardization of Bone Marrow Specimens and Reports was formed by the International Council for Standardization in Hematology (ICSH) to prepare a set of guidelines based on preferred best practices. The guidelines were discussed at the ICSH General Assemblies and reviewed by an international panel of experts to achieve further consensus.

Recent studies have shown that angiogenesis may be involved in the pathogenesis of hematopoietic malignancies, apart from its well-characterized role in the growth and metastasis of solid tumors. In this study, we quantified the degree of angiogenesis in B cell chronic lymphocytic leukemia (B-CLL) by measuring the microvessel density and hotspot density in bone marrow trephine biopsy sections with B-CLL involvement (n ‫؍‬ 12) and compared it to normal bone marrow sections (n ‫؍‬ 11). The B-CLL samples had a mean microvessel count/high power field (hpf) of 7.64 while the control samples had a mean microvessel count/hpf of 2.11 (P ‫؍‬ 0.0001). The mean hotspot density in the B-CLL sections (14.83/hotspot) was also significantly higher (P ‫؍‬ 0.0008) than the mean hotspot density in control bone marrow sections (7.09/hotspot). Both the microvessel density and hotspot density correlated positively with the clinical stage of the B-CLL patients. In a separate cohort of B-CLL patients, the median urine level of the angiogenic peptide, basic fibroblast growth factor (2216.5 pg/g, n ‫؍‬ 14), was significantly higher (P ‫؍‬ 0.0001) than the bFGF level in normal controls (1084 pg/g, n ‫؍‬ 58). These results indicate that angiogenesis may be involved in the pathogenesis of B-CLL.

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Chromosome analysis on CLL-cells from 649 patients revealed clonal changes in 311 cases (48%). The most common abnormalities were trisomy 12 (n = 112), and structural changes on the long arm of chromosome 13 (n = 62), most of them interstitial deletions or translocations involving 13q14, the site of the retinoblastoma gene. Complex karyotypes were associated with poor prognosis, although karyotypic changes rarely develop during the course of the disease. Among patients with single chromosomal abnormalities those with trisomy 12 had a poor survival, whereas those with structural changes on chromosome 13 had as good a prognosis as patients with a normal karyotype.

Sox11 is a transcription factor involved in embryonic neurogenesis and tissue remodeling. Its role in lymphopoiesis is presently unknown. Recent studies have shown the nuclear expression of sox11 in mantle cell lymphoma, which raises the question about its possible association with t(11;14)(q13;q32), the genetic hallmark of mantle cell lymphoma leading to the overexpression of cyclin D1. In this study, we examined sox11 expression in 211 cases of B-cell neoplasms by immunohistochemistry, and evaluated its association with t(11;14) and overexpression of cyclin D1. Nuclear staining of sox11 was observed in 54 of 57 (95%) mantle cell lymphomas, including 52 of 53 (98%) classical and 2 of 4 variant types. Two of the three mantle cell lymphomas negative for nuclear sox11 staining were analyzed and were positive for t(11;14). All other B-cell lymphomas (114 cases) showed variable positive staining in the cytoplasm, but no nuclear positivity. Sox11 was then examined in plasma cell myeloma and hairy cell leukemia as a subset of plasma cell myeloma carry t(11;14) and overexpress cyclin D1, and cyclin D1 is overexpressed in a subset of hairy cell leukemia independent of t(11;14). We found no nuclear staining of sox11 in 30 plasma cell myelomas examined, including 12 cases with t(11;14)(q13;q32). It is interesting that intense nuclear staining of sox11 was present in a subset of hairy cell leukemias (5 of 10), and was associated with the overexpression of cyclin D1. Our results indicate that the nuclear expression of sox11 is highly associated with mantle cell lymphoma, but is independent of t(11;14)(q13;q32) in non-mantle cell B-cell neoplasms. Its association with the overexpression of cyclin D1 in hairy cell leukemia suggests that sox11 may be involved in the upregulation of cyclin D1 in this leukemia.

Recent studies indicate that angiogenesis is important in the pathogenesis of leukemias, apart from its well-established role in solid tumors. In this study, the possible role of angiogenesis in acute promyelocytic leukemia (APL) was explored. Bone marrow trephine biopsies from patients with APL showed significantly increased microvessel density and hot spot density compared with normal control bone marrow biopsies.

The production of tumors through solid-state mechanisms has been demonstrated in experimental animals, but foreign body tumorigenesis has not been proven definitively in man. The authors report three patients with angiosarcoma that occurred in intimate association with foreign material retained for prolonged periods. Although several etiologic factors have been defined in angiosarcoma, foreign bodies generally are not appreciated to have this potential. Review of the literature disclosed six cases of angiosarcoma and 40 cases of sarcomas of other histologic types associated with foreign material, with latency periods of from 4 months to 63 years. Implanted foreign material thus should be considered capable of inducing virtually any form of sarcoma in humans.

Chronic lymphocytic leukemia (CLL) is recognized as a distinct entity. However, morphologic and immunophenotypic heterogeneity exist. Twenty-six patients with CLL were studied to investigate whether an association exists among peripheral blood karyotype, morphology and immunophenotype. Clonal cytogenetic abnormalities were detected in 14 patients (53%), using conventional karyotyping techniques in addition to fluorescence in situ hybridization (FISH) for chromosome 12. By FAB guidelines, 7 of the 8 patients (88%) with trisomy 12 had mixed cell morphology compared to only 3 of 18 (17%) without trisomy 12 (P = .004). One patient (12%) with trisomy 12 had lymphocyte morphology typical for CLL. Six of the eight (75%) with trisomy 12 had atypical immunophenotype including one or more of the following: strong CD20 expression, strong surface light chain expression, or absence of CD23 expression. Only 2 of the 18 patients (11%) without trisomy 12 had atypical immunophenotype (P = .005). None of the three patients with clonal structural abnormalities of chromosome 13q14 had mixed cell morphology or atypical immunophenotype. One of the 12 patients (8%) without clonal cytogenetic abnormalities had mixed cell morphology and one had atypical immunophenotype. This study suggests that a correlation exists among karyotype, morphology, and immunophenotype in CLL, and that CLL subgroups can be identified based on laboratory parameters. Although normal karyotypes or clonal structural abnormalities of 13q14 are associated with morphology and immunophenotype considered typical for CLL, trisomy 12 is associated with mixed cell morphology and atypical immunophenotype. These findings may have implications for evaluating variation in both disease course and response to emerging therapies.