[1543] The Utility of Unilateral Bone Marrow Biopsy in the Staging of Non-Hodgkin's Lymphoma

Asif S Shahab, Muhammad Zulfiqar, Abdul Mannan, Michelle Bonnett, Zyad Kafri. St John Hospital and Medical Center, Detroit, MI

Background: Bone marrow (BM) biopsy is integral for the staging of patients with non-Hodgkin's lymphoma (NHL). Bilateral BM biopsies have been the standard practice in many institutions. In this study, our aim is to explore whether a unilateral BM biopsy is comparable in yield to bilateral biopsies in the staging of patients with NHL.
Design: We retrospectively reviewed electronic pathology reports for BM biopsies done at our institution for staging NHL. We also collected data for age, gender, type of NHL, percentage of disease involvement, and size of biopsy. Patients were divided into those who had bilateral biopsies vs. unilateral biopsies. The bilateral group was further divided into bilaterally positive versus only one side (aspirate and/or biopsy) positive.
Results: Between 1995 and 2010, 256 patients were identified with the diagnosis of NHL. Of these, 146 patients (57%) had low grade NHL and 83 patients (32.4%) had diffuse large B-cell NHL. 107 patients had bilateral and 149 had unilateral BM biopsies. Overall, the positivity rate was 46.7% for bilateral and 41.4% unilateral (chi square, p = 0.884). For the low grade NHL group, the positivity rate was 56.2% for bilateral and 57.9% unilateral. For the diffuse Large B-cell NHL group, the positivity rate was 26.7% for bilateral and 23.7% unilateral. In the bilateral group of 107 patients, 97 patients had bilateral positive results and 10 had only one side positive. Within the bilateral group, the sensitivity of either side being positive (i.e. left side vs. either, or right side vs. either) was 90% and the negative predictive value was 92%. The positivity rate of unilateral BM biopsies with size of >=2cm was 10% more than that with size <2cm but this difference was not statistically significant (chi square, p = 0.319). We also detected a gender difference with right to left side results agreement better in men (p =0.03). This may be due to the difference in mean biopsy size found in our study by gender and side. The mean size of right side biopsy in bilateral positive group was (1.74 cm) in males vs. (1.16 cm) in females (t-test, p = 0.025).
Conclusions: The yield of unilateral BM biopsy in the staging of NHL is quite comparable to bilateral BM biopsy. The sensitivity and negative predictive values of unilateral BM biopsy are significantly high. Therefore, unilateral BM biopsy can be routinely offered instead of bilateral BM biopsy for the staging of NHL. This would help improve patient comfort and minimize the cost and time of this procedure.
Category: Hematopathology

Tuesday, March 20, 2012 1:00 PM

Poster Session IV # 213, Tuesday Afternoon


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