Читать книгу Pathy's Principles and Practice of Geriatric Medicine - Группа авторов - Страница 618

A critical component of the bone marrow aspiration is the cytogenetic examination of the bone marrow, which may help to establish the diagnosis and yields important prognostic information. It is well established that cytogenetic patterns are very heterogeneous in MDS.⁴¹

Roughly 60% of patients with MDS have a normal karyotype, but the presence of a common cytogenetic abnormality may establish the diagnosis in difficult cases.⁴² One series found that cytogenetic abnormalities were more common in the advanced stages of MDS compared with the less‐advanced MDS subtypes.⁴³

The more common abnormalities are trisomy 8 and deletions of the long arms of chromosomes 5, 7, 11, 13, and 20. Complex karyotypes, defined as three or more cytogenetic abnormalities, are found in 15% of cases and confer a poor prognosis.^41,43 Deletion of 5q is seen commonly in patients with refractory anaemia and represents a distinct clinical syndrome, the ‘5q syndrome’.

Therapy‐related MDS is also associated with specific chromosomal abnormalities. In particular, partial or complete loss of chromosome 5 or 7 has been seen after exposure to alkylator therapy.

Cytogenetics is not only strongly correlated with the calculation prognosis but also important for the selection of the most effective therapy; thus, a complete bone marrow karyotype remains the standard workup evaluation procedure of the patient with MDS.⁴⁴ Cytogenetic prognostic groups have been proposed in the revised international score (IPSS‐R) scheme, which includes 5 different subgroups with 20 different alterations.^44,45