[Value of imprint in bone marrow morphological examination]

To explore the role of bone marrow (BM) imprint in the diagnosis of hematological diseases.

Between January 2002 and June 2008, a total of 3024 cases with BM smears, imprints and sections conducted simultaneously were recruited. There were 1667 males and 1357 females with a median age of 55 years old (range: 7 to 92). The cellularity on imprint and smear was evaluated with the standard cellularity on BM section. With the integrative diagnosis (including all examinations and clinical outcomes) as the standard, the diagnostic accuracy of hematological diseases were compared between BM imprint, smear and section groups. Another 79 cases of lymphoma and 114 cases of plasma cell myeloma (PCM) were selected for a correlation analysis of tumor cell infiltration patterns.

BM imprint contained hematopoietic and non-hematopoietic regions and cells retained integrated structure. The cellularity evaluation by imprint was superior to smear overall. In BM imprint group, the diagnostic accuracy for hypersplenism (n = 130), metastatic carcinoma (n = 67), refractory anemia with excess blasts, myeloproliferative neoplasm (n = 174), and PCM (n = 94) were better than smear group (96.9% vs 80.7%, 91.0% vs 76.1%, 92.6% vs 81.5%, 92.5% vs 76.4%, and 97.8% vs 92.6% respectively, all P < 0.05); And the diagnostic accuracy for megaloblastic anemia (n = 69), acute myeloid leukemia (n = 104), refractory cytopenia with unilineage dysplasia (n = 15), refractory cytopenia with multilineage dysplasia (n = 22), and lymphoplasmacytic lymphoma (n = 12) were higher than biopsy section group (100% vs 84.0%, 91.3% vs 74.0%, 86.7% vs 60.0%, 90. 9% vs 72.7%, and 66.6% vs 50.0% respectively, all P < 0.05); And the diagnostic accuracy for myelodysplastic/myeloproliferative neoplasm (n = 26) was higher than smear group (76.3%, P < 0.05) and biopsy section group (78.2%, P < 0.05). Excellent correlations existed between BM imprint and section of the patients with lymphoma or with PCM (r = 0.90, r = 0.78, both P < 0.05).

BM imprint contains the characteristics of both smear and section. BM imprint is superior to smear for an evaluation of cellularity. And it is also better than section for an analysis of cytological changes.