Article Type

Original Study


Objective: The aim of this study was to assess the expression of collagen I and III in fibrotic bone marrow (BM) in different pathologies. Background: A wide variety of benign conditions and malignant disorders are associated with BM fibrosis. BM fibrosis can be demonstrated by histochemical staining using silver impregnation or by trichrome stains. Immunohistochemical stains, especially anticollagen I and III, are also used for more accurate assessment of BM fibrosis. This study demonstrates the expression of collagen I and III in fibrotic marrow in different pathologies. No clinical data, prognosis , survival were mentioned in this study and so the impact was not investigated. Materials and methods: In this study 50 formalin-fixed paraffin-embedded BM biopsy samples were selected from archived cases at the Clinical Pathology Department, Cairo University. These 50 cases included seven cases with myeloproliferative neoplasms, 14 with lymphoproliferative disorders, three with acute leukemia, four with metastasis, and 22 with reactive BM changes. Cases were divided into two groups according to the Masson's trichrome staining pattern: the fibrotic group, which included 13 cases, and the nonfibrotic group, which included 37 cases. The included cases were subjected to reticulin and trichrome stains, in addition to assessment of collagen I and III expression by immunohistochemistry. Results: As regards collagen I and III staining grades, grade 4 was significantly higher in the fibrotic group, whereas grade 0 was significantly higher in the nonfibrotic group. Conclusion: Collagen I and III are markedly expressed in fibrotic marrow and marrow fibrosis; in particular, collagen fibrosis appears to be more evident in myeloproliferative neoplasms and in tumor metastasis to the BM.