When a bone marrow exam without cytological abnormalities should be considered truly normal?

Background: Blood and bone marrow cytological examination represents the unique tool to explore the hematopoietic tissue that can be altered by several intrinsic and extrinsic conditions Cytological assessment of the bone marrow is indicated in several situations including hemogram alterations, hypercalcemia, hyperproteinemia staging for malignancies and monitoring of chemotherapy administration. Objectives: The purpose of this cytologically retrospective study was to evaluate a consistent number of qualitative and quantitative normal bone marrow exams according to the hematological and clinical-pathological data to judge if this normality is by itself a pathologic state. Methods: Six hundred and thirteen bone marrow samples were examined using morphological and numerical criteria together with a complete hemogram. The bone marrow cytological examinations were performed after the identification of hematological or clinical alterations such as cytopenia, increased number of cells, positive leishmania serological result and staging of neoplasia. Results: Of the 613 bone marrow samples evaluated, 85 (14%) were classified as normal. However only 28 (33%) of those cases has a normal hemogram associated, whereas 55 (65%) has one or more cytopenia and 2 (2%) has increased blood cells count. Conclusions: From this retrospective study emerge that cytological bone marrow examinations without any morphological or numerical abnormalities are often associated with altered hematological exams and for this reason they should not be considered normal and should lead to other deepened investigations and sometimes to a second cytological bone marrow exam after some days.