Solid tumour with initial presentation in the bone marrow--a clinicopathologic study of 25 adult cases

This study reviews the clinicopathologic features of 25 adult patients without a known history of malignancy presenting with metastatic carcinoma in the bone marrow. The disease mainly affected middle-aged to elderly males (mean age, 61.6 years). Bone pain, generalized or confined to the back, was a common presenting complaint. Organomegaly was often absent. Laboratory abnormalities included anaemia, leukocytosis, thrombocytopenia and a leukoerythroblastic blood picture. Serum alkaline phosphatase level was raised in the majority of cases. In about one-third of the cases, malignancy was not suspected clinically, and bone marrow aspiration was carried out because of incidental finding of abnormal blood counts. The marrow aspirate findings were characterized by numerous to sparse cohesive tumour clusters with nuclear moulding. Over two-thirds of the patients had metastatic adenocarcinoma, and the lung was found to be the commonest site of primary disease. We conclude that since the marrow infiltration can be subtle, marrow smears should be carefully scrutinized for tumour cells in patients with leukoerythroblastic blood picture, in particular those with an elevated serum alkaline phosphatase level.