Résumé
INTRODUCTION: Bone marrow involvement by a non-haematological malignancy gives an opportunity to identify the lodgement, invasion of metastatic cells and the response of the host to the tumor cells. The study was undertaken to assess the involvement of bone marrow with non-haematopoietic malignancies and its significance in establishing primary diagnosis in clinically unsuspected cases. MATERIALS AND METHODS: This was a descriptive study which included record review of the departmental archives for the last five years (January 2007 to December 2011). Eighty four cases were studied; which included clinically diagnosed non-haematological malignancy for staging or symptomatic cytopenias/bony lesions (group 1, n = 63), clinically suspected bone marrow metastasis of unknown primary malignancy due to symptomatic cytopenias/bony lesions (group 2, n = 07) and clinically unsuspected malignancy with incidentally detected bone marrow metastasis (group 3, n = 14). RESULTS: Bone marrow metastases of solid tumors were identified in 23 cases (27.3%) which included 9 cases from group 1, 14 cases from group 3 and nil in group 2. Of the 14 cases in group 3, in 12 cases a definitive diagnosis could be made by correlating clinicoradiological findings with morphology and immunohistochemistry. The most common tumor in pediatric cases were neuroblastoma and Ewing’s sarcoma (40%) and in adult’s adenocarcinoma of gastrointestinal tract (30.7%) was the commonest. CONCLUSION: Bone marrow metastasis can masquerade as a primary haematopoietic disorder; however its detection has both therapeutic and prognostic significance. Immunohistochemistry is a useful adjunct to morphology in reaching a definitive diagnosis.