Spontaneous remission in adults with primary myelodysplastic syndromes: incidence and characteristics of patients.

Reports on spontaneous remissions in patients with primary myelodysplastic syndromes (MDS) occasionally appear in the literature. We report five adult patients with spontaneous remission of MDS, achieved without cytotoxic or any other treatment. These five patients represent 1.6% of 307 MDS patients, diagnosed in our Institute since 1987. According to FAB criteria, three patients had RA, and one patient had RARS and RAEB, each. All patients were women, median age of 63 yr (range 32-68 yr). Patients were without significant complaints and peripheral cytopenia was mild. Bone marrow dyshematopoiesis was also mild, mostly affecting erythroid and megakaryocytic series. At diagnosis, three patients had cytogenetic abnormalities [+8,+12; +15 and del(16)(q22)]. Median time to complete hematological and cytogenetical remission was 51 mo, while median duration of spontaneous remission was 45 mo (range 44-60 mo). As for the follow-up, none of the patients relapsed. In conclusion, although spontaneous remissions (i.e., "regression") of MDS are uncommon, better understanding of their basis may lead to crucial advances in the study of leukemogenesis.