Evaluation of bone marrow in 143 lymphomas: the relative frequency and pattern of involvement, secondary myelopathies, pitfalls and diagnostic validity.

UNLABELLED: The aim of the present study is to assess the frequency of bone marrow (BM) involvement by both bone marrow aspirate and biopsy (BMA and BMB, respectively) procedures in established cases of lymphomas at initial presentation, and to study the relative frequency of marrow disease in relation to lymphoma types, patterns of infiltration and the 2ry associated changes, as well as the diagnostic challenges. Moreover, the diagnostic validity of BMA is tested taking the results of the BMB as the true test results, in order to determine the role of each procedure in the diagnostic approach of marrow infiltration.

PATIENTS AND METHOD: This is a retrospective study carried out on 143 nonconsecutive Egyptian patients with lymphomas obtained from a private series during the years 2005 to 2008. Criteria of inclusion included the availability of full medical records and material (medical and pathological), patient consent, nodal disease with no therapy prior to BM sampling, except in 7 patients who had another 2nd BMB following therapy. BMA and BMB were performed as part of the routine workup for diagnosis and staging of lymphoma. The patients had a male to female sex ratio of 2.6:1 and a wide age range from 4 to 74 years.

RESULTS: In the present series, 64 cases out of the 143 lymphoma patients studied (44.8%) had a BM disease. Involvement was mostly bilateral (80%). Patients older than 40 years showed higher incidence of bone marrow involvement. There was complete concordance (100%) between both diagnostic procedures in the detection of 76 marrow disease-free lymphoma patients. BMA showed no false positive results and a low rate of deference that makes of it an ideal screening test. Three deferred smears of CLL for BMB diagnosis were all positive for involvement. However, in a total number of 64 BMB positive patients, aspirates could only identify lymphoma involvement in 42 lymphoma patients and missed 22 patients with a BM disease, with an overall sensitivity rate of 65.6%. BMB had a high diagnostic viability and is an easily applied reproducible procedure for diagnosis of BM involvement based on a more detailed informative analysis of both architectural and individual cytomorphologic changes.

CONCLUSION: The relatively high level of BM involvement in Egyptian lymphoma patients was directly proportional to high-risk factors. The diagnostic validity of BMB is higher than that of BMA. However, BMA serves as a good positive test in screening lymphomas for marrow disease. A negative BMA does not exclude involvement. Thus, smears should be taken as a complimentary procedure.