Clonal cytogenetic abnormalities in bone marrow specimens without clear morphologic evidence of dysplasia: a form fruste of myelodysplasia?

Cytogenetic abnormalities suggestive of a myeloid disorder are occasionally observed in the bone marrow (BM) cells of patients with morphologically and immunohistochemically unremarkable marrow aspirates and biopsies. Between 1994 and 2000, 55 such patients were seen at our institution (34 men; median age of 66 years). The indications for BM sampling included unexplained cytopenias (31 patients), staging or follow-up of a lymphoproliferative disorder or a plasma cell dyscrasia (18 patients), or another miscellaneous reason (6 patients). Specific cytogenetic abnormalities included a 20q deletion or monosomy 20 (10 patients), a chromosome 7 deletion (8 patients), +8 (5 patients), del(5q) or a 5q translocation (4 patients), and del(13q) (2 patients). Eleven patients had a complex karyotype. As of January 2002, 23 of the 55 patients were dead; median follow-up for living patients is 20 months. Of the 23 dead patients, 1 died of acute myelogenous leukemia (AML) and 6 of complications related to cytopenias. This study provides support for obtaining cytogenetic studies in patients with unexplained cytopenias if a morphologic explanation for the cytopenias is lacking. Continued follow-up of this heterogeneous cohort and further studies of similar patients will more clearly define the disease processes and prognosis for this constellation of laboratory findings.