In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: There were two cases of hypocellular myelodysplasia , two cases of hypersegmented myelodysplastic granulocytosis , two cases of hypercellular marrow with abnormal megakaryocytes with bizarre nuclei , one case of megakaryocytic myelosis associated with a hyperplastic marrow , dysmyelopoiesis and a hypocellular marrow and two cases of myelodysplasia with dyserythropoiesis , hemosiderosis and a hypocellular marrow .
### Output Text:
There were two cases of hypocellular myelodysplasia , two cases of hypersegmented myelodysplastic granulocytosis , two cases of hypercellular marrow with abnormal megakaryocytes with bizarre nuclei , one case of megakaryocytic myelosis associated with a hyperplastic marrow , dysmyelopoiesis and a hypocellular marrow and two cases of myelodysplasia with dyserythropoiesis , hemosiderosis and a hypocellular marrow . 