Preleukemia: bone marrow histopathology in myelodysplasia and preleukemic syndrome

Bone marrow histological findings in systemic lupus erythematosus with hematologic abnormalities: a clinicopathological study

BACKGROUND

The histopathologic features characterizing the involvement of the bone marrow (BM) in systemic lupus erythematosus (SLE) have not been systematically analyzed to date.

OBJECTIVES

The aim of this study was to assess morphologic and immunohistochemical characteristics of BM involvement in SLE.

PATIENTS AND METHODS

Clinical and serological data of 40 SLE patients with unexplained cytopenias were studied. Ten patients with myelodysplasia of refractory anemia (RA) were used as controls. BM aspiration, BM biopsy (BMB), and immunohistochemistry were carried out in patients and controls. BM fibrosis, BM necrosis, stromal edema, and abnormal localization of immature precursors (ALIP) were assessed according to standard criteria.

RESULTS

Dyserythropoiesis and megakaryocytic atypias were uniform findings in SLE patients. The disruption of the normal BM architecture was a predominant SLE BM feature affecting cells of all three hemopoietic lineages, with both erythroid and megakaryocytic precursors tending to assume paratrabecular locations and ALIP aggregates being present in 27 cases. In addition, BM was hypocellular in 23 cases. BM necrotic alterations were evident in 90% of the cases. The density of reticulin content was generally increased. Vascular changes including dilatation of sinuses were manifest and were associated with the presence of necrotic alterations (P = 0.008). Hemoglobin levels correlated inversely with the presence of ALIP (P = 0.016). Upon comparing BMB features between SLE and RA controls there were striking similarities.

CONCLUSIONS

BMB in patients with SLE and unexplained cytopenias presents a variety of histopathologic findings including BM necrosis, stromal alterations, hypocellularity, dyspoiesis, and distortion of normal BM architecture, characterized primarily by the presence of ALIP aggregates.

Macrophages (phagocytic-histiocytic reticular cells) in reactive-inflammatory lesions of the bone marrow and in myelodysplastic syndromes (MDS). An immunohistochemical and morphometric study by use of a new monoclonal antibody (PG-M1)

An immunohistochemical and morphometric study was performed on trephine biopsies of the bone marrow in 52 patients (28 males/24 females; age 68 years) with various subtypes of myelodysplastic syndromes (MDS) to determine the number of macrophages (phagocytic-histiocytic reticular cells). Quantifications included the haemosiderin-storing subpopulation (Prussian-blue reaction) of this lineage as well as the iron-free compartment. The latter was identified by a new monoclonal antibody (PG-M1) which is specifically directed against histiocytic reticular cells. Bone marrow specimens of individuals without haematological disorders and those showing reactive lesions served as controls. In comparison with the normal bone marrow and inflammatory changes (i.e. rheumatoid arthritis) 23 of the 52 patients with MDS revealed a significant increase in macrophages. This increase encompassed not only the iron-laden subpopulation but also the total number of phagocytic reticular cells. Accumulation of macrophages in MDS was speculated to be due to a premature and enforced degradation of dysplastic cell elements leading to phagocytosis of haemosiderin and debris material. Moreover, cells of the monocyte-macrophage system could be involved in the complex pathomechanism of fibrillogenesis, since in a considerable percentage of patients with MDS, an increase in reticulin (argyrophilic) fibres was noticeable. Our finding of an expansion of the macrophage compartment in about half of the patients with MDS is in keeping with results of cell culture studies on colony formation of granulocyte-macrophage precursors (CFU-GM).

Bone marrow trephine interpretation: diagnostic utility and potential pitfalls

Good quality paraffin-embedded sections can be obtained from bone marrow trephines, allowing the routine use of these biopsies in diagnostic histopathology. Trephines are superior to aspirates, especially for the assessment of marrow cellularity, the extent and pattern of tumour infiltration and the cell type. Bone marrow biopsies are useful in several areas, e.g. non-haematological disorders, myelodysplasia, the myeloproliferative group, lymphomas and leukaemias, which are briefly discussed below. Further advances in interpretation are likely with more frequent use of bone marrow trephines.

Abnormal localization of immature precursors (ALIP) in the bone marrow of myelodysplastic syndromes: current state of knowledge and future directions

It has been suggested that the occurrence of abnormal localization of immature precursors (ALIP) in the bone marrow biopsy (BMB) may be of diagnostic and prognostic significance in myelodysplastic syndromes (MDS). The recognition of ALIP has been based exclusively on bone marrow histological appearances. During the last decade technical advances have led to the widespread use of various immunophenotypic markers for the diagnostic and prognostic purposes which has contributed enormously in understanding the development of haemopoietic cells and the cellular origin of various haematological malignancies. In addition proliferation antigens, growth factors, oncogenes, anti-oncogenes and other biological discoveries have opened new vistas to our knowledge of the normal and neoplastic growth processes. Despite this, the precise nature of ALIP and their significance in relation to the aetiopathogenesis and evolution of MDS remains unclear. Indeed the diagnostic value of ALIP in MDS is debatable. Furthermore, the precise cell lineages which comprise ALIP are not defined. The purpose of this review is to address these issues and to incorporate our new findings on the histological and immunophenotypic characterization of immature cell aggregates.