Three-dimensional reconstruction of non-Hodgkin's lymphoma in bone marrow trephines

Differentiating Benign From Malignant Bone Marrow B-Cell Lymphoid Aggregates: A Statistical Analysis of Distinguishing Features

Context

Lymphoid aggregates are seen in a minority of bone marrow biopsy specimens, and when present, their neoplastic nature is often apparent by morphologic evaluation. However, the distinction between benign and malignant aggregates can be a diagnostic challenge when there are multiple aggregates with no documented history of lymphoma.

Objective

To aid in the distinction between benign and malignant B-cell lymphoid aggregates.

Design

Previously, we described specific distribution patterns for B and T lymphocytes within bone marrow aggregates. To statistically analyze the significance of these patterns as well as previously reported criteria, we examined 128 bone marrow specimens with benign aggregates and 78 specimens with documented malignant B-cell aggregates and calculated specific odds ratios (ORs) and 95% confidence intervals (CIs) to aid in differentiating between benign and malignant B-cell aggregates.

Results

Aggregates with infiltrative edges (OR, 80.54; 95% CI, 31.76–204.21), a B-cell pattern (OR, 30.08; 95% CI, 13.28–68.10), paratrabecular location (OR, 10.17; 95% CI, 3.96–26.12), size greater than 600 μm (OR, 6.83: 95% CI, 3.61–12.93), or cytologic atypia correlated with malignancy.

Conclusion

When taken collectively, the presence of more than 2 of these characteristic features was strongly predictive of malignancy.

Three-dimensional reconstruction of tumor microvasculature: simultaneous visualization of multiple components in paraffin-embedded tissue

Three-dimensional (3D) visualization of microscopic structures may provide useful information about the exact 3D configuration, and offers a useful tool to examine the spatial relationship between different components in tissues. A promising field for 3D investigation is the microvascular architecture in normal and pathological tissue, especially because pathological angiogenesis plays a key role in tumor growth and metastasis formation. This paper describes an improved method for 3D reconstruction of microvessels and other microscopic structures in transmitted light microscopy. Serial tissue sections were stained for the endothelial marker CD34 to highlight microvessels and corresponding images were selected and aligned. Alignment of stored images was further improved by automated non-rigid image registration, and automated segmentation of microvessels was performed. Using this technique, 3D reconstructions were produced of the vasculature of the normal brain. Also, to illustrate the complexity of tumor vasculature, 3D reconstructions of two brain tumors were performed: a hemangioblastoma and a glioblastoma multiforme. The possibility of multiple component visualization was shown in a 3D reconstruction of endothelium and pericytes of normal cerebellar cortex and a hemangioblastoma using alternate staining for CD34 and alpha-smooth muscle actin in serial sections, and of a GBM using immunohistochemical double staining. In conclusion, the described 3D reconstruction procedure provides a promising tool for simultaneous visualization of microscopic structures.

Immunohistochemistry in bone marrow pathology: a useful adjunct for morphologic diagnosis

Pathomorphological examination of trephine biopsies of the bone marrow (BM) represents a standard method for the diagnosis and staging of hematologic neoplasms and other disorders involving the BM. The increasing knowledge about the genetic basis and biology of hematologic neoplasms, as well as the recently proposed WHO classification system, provide the framework for an accurate diagnosis. Although conventional morphology remains the gold standard for paraffin-embedded BM trephines, immunohistochemical stainings have become an integral part of the diagnostic workup. Antibodies suitable for paraffin sections are generally applicable to BM trephines, but modifications of staining protocols may be necessary due to the alternative fixatives and decalcification procedures used for BM biopsies. The indications for immunostainings range from confirmation and classification of lymphoma involvement, subclassification of acute leukemias, and estimating blast counts in myelodysplastic and myeloproliferative syndromes to characterization of BM involvement in nonhematologic neoplasms. Although subtyping of NHL in the BM is more difficult from the point of morphology, classification of the entities that frequently involve the BM, especially the small B-cell lymphomas, can easily be achieved with the help of immunohistochemistry. In this review, we try to summarize the current state of the art in BM immunohistochemistry for the diagnosis of hematologic disorders. Moreover, diagnostic algorithms and useful antibody panels are proposed for a rational and cost-effective approach.

Polymerase chain reaction-based diagnosis of bone marrow involvement in 170 cases of non-Hodgkin lymphoma

BACKGROUND

Up to the current time, diagnosis of bone marrow (BM) involvement in non-Hodgkin lymphoma (NHL) has been based on morphologic findings. Polymerase chain reaction (PCR) for antigen receptor gene rearrangements has the potential to increase the detection sensitivity of minimal degrees of BM involvement. The authors therefore assessed PCR-based clonalities of BM concurrently with morphology from 170 cases with NHL and evaluated the usefulness of comparative analysis of clonalities between bilateral BMs and the lymph node and the clinical significance of PCR based clonalities of BM.

METHODS

Bilateral BM clot sections of 170 cases and 47 lymph nodes were tested for immunoglobulin heavy chain gene rearrangement or T-cell receptor gamma gene rearrangement according to the B- or T-lineage of the lymph node.

RESULTS

When compared with morphology, the results of PCR showed an unexpectedly low positive concordance rate of 61.0% for B-cell NHL and 57.1% for T-cell NHL. When the clonality of BM was compared with that of lymph nodes in B-cell NHL, bilateral clonalities of BM showed high concordance with the clonality of the lymph nodes. PCR-based clonality did not show significant impact on survival.

CONCLUSIONS

Morphology remains the gold standard in the evaluation of BM involvement by NHL. Although the comparative analysis of BM clonality and that of the lymph nodes is considered a valuable tool that increases the reliability of clonality, PCR-based clonality of BM does not significantly add to the sensitivity of diagnosing BM involvement by NHL.