Granulocytic sarcoma presenting as pulmonary nodules and lymphadenopathy

A patient presented with anterior and posterior cervical lymphadenopathy as well as widespread intrapulmonary nodules. Histologic sections of both lymph node and lung revealed dense infiltration by sheets of cells which were cytochemically positive for chloroacetate esterase and myeloperoxidase, thus suggesting a diagnosis of granulocytic sarcoma. The patient was initially treated with daily hydroxyurea. After 6 weeks, when progression of the disease was apparent, hydroxyurea was discontinued and the patient was placed on mithramycin, an agent reported to induce differentiation of myeloid precursor cells both in vitro and in vivo. On this latter agent, a dramatic response has been noted with a decrease in the pulmonary symptoms, and a marked reduction in the size of the lymph nodes and lung nodules. The authors report this case because it represents a rare presentation of an uncommon disease and because of the striking improvement that followed the initiation of a novel therapeutic modality.