Successful routine cytogenetic analysis from trephine biopsy specimens following failure to aspirate bone marrow

Abstract

The clinical importance of determining marrow cytogenetics in haematological malignancy is well recognised (Greenberg et al, 1997; Grimwade et al, 1998) particularly with regard to the determination of prognosis and on occasion, diagnosis. Not infrequently, however, a ‘dry’ bone marrow aspirate (BMA) precludes successful cytogenetic analysis. In these circumstances, peripheral blood may be an option if circulating blast cells are of sufficient frequency to allow metaphase preparations, although this is often not the case. Over the last 5 years we have submitted a trephine sample (either an additional core or a piece of the initial core in standard tissue culture medium) to our local genetics laboratory in 20 cases where cytogenetic analysis was deemed necessary and marrow aspiration had failed. On receipt, these specimens were agitated gently by hand to free cellular material from the biopsy and subsequently processed using standard methodology. Adequate metaphases for analysis were obtained in five cases, a yield of 25%. The three cases featured illustrate the usefulness of this approach. Case 1. A 64-year-old female had a history of breast carcinoma, treated with surgery, adjuvant chemotherapy [Epirubicin/CMF (cyclophosphamide, methotrexate, 5-fluorouracil)], local radiotherapy and Tamoxifen, 3 years prior to presentation. In March 2005 she presented with shingles and was found to be pancytopenic. A blood film showed neither blasts nor obvious promyelocytes. The initial aspirate was a dry tap. Due to the possibility of a secondary haematological malignancy, a trephine core piece was sent for urgent cytogenetic analysis. This revealed translocation t(15;17). Induction chemotherapy was instituted immediately. The patient remains in remission following treatment on the Spanish arm of the acute myeloid leukaemia (AML) 15 protocol. Case 2. A 58-year-old female presented with anaemia and thrombocytopenia with dysplastic features on blood film. BMA was a dry tap. Trephine cytogenetics revealed monosomy 5 and 7 plus multiple complex abnormalities in keeping with the morphological diagnosis of acute panmyelosis. Unfortunately the patient died of sepsis and respiratory failure prior to treatment. Case 3. A 40-year-old male presented with a leucoerythroblastic film, thrombocytopenia and splenomegaly. Again an aspirate was not obtainable. Chronic myeloid leukaemia was suspected and the absence of the Philadelphia chromosome abnormality in all of 20 cells obtained helped exclude this diagnosis. Two further cytogenetic results were obtained from this method and revealed a normal karotype in both cases. In one young female patient with a diagnosis of acute lymphoblastic leukaemia, normal cytogenetics were obtained from 20 cells, excluding a high risk karyotype requiring allogeneic bone marrow transplantation in first remission. If it is not possible to achieve dividing cells through culture by this method, fluorescence in situ hybridization can, of course, be performed on non-dividing cells obtained by this sampling technique. This has resulted in a further seven successful analyses of the cellular material obtained from trephine cores. We recommend, in patients where cytogenetic analysis is of paramount importance to diagnosis and/or prognosis and marrow aspiration has failed, that a second trephine core be sent in standard transport medium. If a sufficiently long trephine is obtained, a section of this may be dissected and used rather than obtaining a second trephine. We believe the yield is sufficiently high enough to warrant this practice and can be performed at no additional cost to that of standard cytogenetic analysis from aspirates. As seen in the above cases, important information can be obtained to guide subsequent patient management using this very simple approach.