Morphology of the bone marrow after stem cell transplantation

Abstract

In many haematological conditions the only curative option is stem cell (SCT) or bone marrow (BM) transplantation. Little information exists about BM morphology following non-ablative engraftment. During the pretransplantation period and depending on the kind of pretreatment, there may be hypoplasia, residual disease and varying degrees of fibrosis. In the post-transplantation period, after 1-3 weeks of transfusion-dependent pancytopenia, the first signs of successful engraftment are indicated by the recurrence of neutrophils, monocytes and erythrocytes in the peripheral blood. In the BM there is slow regeneration of erythropoiesis, followed by the other lineages of haematopoiesis and increase in reticulin fibres or even a resolution of fibrosis. Diagnostic problems arise when neoplastic lympho- or haematopoiesis are maintained following transplantation. Moreover, there may be a significant graft versus tumour response reaction or an already relapsing disease needing aggressive treatment. On the other hand, a conspicuous dyshaematopoiesis should not be mistaken as representing a myelodysplastic syndrome. The presence of granulomas being treatment-related or a manifestation of intercurrent granulomatous disease has to be considered. More advanced knowledge of the histological features of regenerating BM will certainly aid the recognition of relapsing disease and is needed for the adequate reporting of post-transplant alterations associated with a successful or failing engraftment.

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“…After decalcification with EDTA, sections 4 to 6 μm thick were prepared and stained with hematoxylin and eosin for the evaluation of bone marrow edema. Bone marrow edema was characterized by the accumulation of eosinophilic fluid in the bone marrow interstitium in between univacuolar fat cells, resembling the morphological findings described in the bone marrow of patients with severe malnutrition [12], during the first couple of weeks following stem cell transplantation [13] or after cytoreductive therapy in chronic idiopathic myelofibrosis [14] (Figure 1b; red arrows, edema; black arrow, vacuoles of fat cells). The relative amount of edema, calculated as the percentage of the total bone marrow area, was quantified as described in an earlier study in which bone marrow edema was assessed for a comparative analysis of magnetic resonance (MR) images and histopathology in osteoarthritis [15].…”

Histopathological bone marrow changes after reduced‐intensity hematopoietic stem cell transplantation for follicular lymphoma involving bone marrow

“…Increased relapse rates were observed following T‐cell depletion of the donor graft 22 . Some authors suggest that the number of T lymphocytes in the BM is high, especially in patients in whom GVHD occurs, and CD8‐positive T lymphocytes appear to play an important role in both GVHD and GVL reactions after allo‐SCT 9,23 . We think that the frequent association between lymphoma responses and GVHD suggests that the putative target antigens of alloreactive donor T cells are the target of the GVL effect, although the definitive role of GVHD in the context of a GVL effect is not yet certain.…”

“…We studied hematopoietic reconstitution after reduced‐intensity hematopoietic stem cell transplantation (RIST) in a patient with follicular lymphoma (FL) involving the bone marrow (BM), by evaluating BM biopsy specimens obtained at different time points after RIST. BM biopsy is commonly performed for staging or for initial diagnosis of malignant lymphoma and is important in determining the hematopoietic status of patients after transplantation 7–9 . To the best of our knowledge, this is the first description of histopathological BM changes after RIST for FL involving BM.…”

Myelodysplastic syndrome after allogeneic hematopoietic stem cell transplantation: Diagnostic and therapeutic challenges

“…Van Marion et al reviewed bone marrow histopathology in the post-transplant period and noted frequent dyshematopoiesis with cytoplasmic and nuclear abnormalities in the first months after transplantation. (22) Therefore, additional techniques are required to assess the diagnosis of MDS in the post-transplant period.…”