Myelodysplastic syndrome: diagnostic implications of cytochemical and immunocytochemical studies.

Cytochemical and immunocytochemical studies were performed on bone marrow aspirates from 96 cases of primary myelodysplastic syndrome (MDS), 11 cases of secondary MDS, 22 cases of non-MDS hematologic disorders, and 10 cases of nondiagnostic, apparently normal marrow specimens to determine the practicality and utility of these stains for diagnosing MDS. Cytochemical studies included iron stain, periodic acid-Schiff (PAS), peroxidase, butyrate esterase, chloroacetate esterase, and double esterase stains. Immunocytochemical staining was done with monoclonal antibody HP1-1D, which recognizes the glycoprotein IIb/IIIa complex in megakaryocytes. The iron stain remained most helpful in identifying abnormal ringed sideroblasts, a feature of dyserythropoiesis, and thus in supporting the diagnosis of MDS. The PAS stain was helpful, if positive, in identifying patients with MDS; however, when it was negative, this stain did not help distinguish MDS from non-MDS hematologic disorders. The immunocytochemical stain with HP1-1D monoclonal antibody was also helpful in identifying atypical micromegakaryocytes, indicative of dysmegakaryopoiesis. Other cytochemical abnormalities were infrequently observed and were less specific for the diagnosis of MDS. The combination of two stains--for example, PAS and iron stain or PAS and double esterase--was helpful, however, in excluding MDS, inasmuch as neither the miscellaneous nor the control group stained positively with these combinations.