Primary myelofibrosis with normal karyotype and cryptic aberrations detected by FISH: case report

Abstract

Introduction. Myeloproliferative neoplasms (MPNs) are the result of clonal haematopoietic stem cell disorders. The most common cytogenetic aberrations are: partial trisomy 1q, 13q–, 20q–, trisomy 8 and abnormalities of chromosomes 1, 7 and 9. Conventional karyotyping is a routinely used method. Fluorescent in situ hybridisation (FISH) analysis however may also be an integral component of the diagnostic evaluation, especially when the abnormality is cryptic.

Subject and methods. A 70-year-old woman was admitted to the Department of Haematology in September 2013 with suspected acute myeloid leukemia (AML). The final diagnosis was primary myelofibrosis and NYHA class III heart failure. Bone marrow (BM) was used for karyotyping and FISH. Peripheral blood (PB) was used for PCR.

Results. Cytogenetic GTG analysis revealed normal female karyotype — 46,XX [22]. The result of analysis of JAK2 V617F mutation was negative. Analysis using LSI BCR/ABL Dual Fusion Probe, JAK2 Break Probe and RB1 Deletion Probe showed abnormal cells, of which the numbers were beyond the normal cutoffs. FISH examinations using p53 Deletion Probe and LSI CDKN2A/CEP 9 showed normal cells.

Conclusion. The diagnosis of primary myelofibrosis may pose a problem. We still do not know the specific abnormalities (i.e. genomic and chromosomal aberrations or gene mutations), the occurrence of which may help to diagnose and assess a probable time of survival of patients with PMF. Further examinations are needed (e.g. using aCGH) to find out more about myeloproliferative neoplasms.