[Primary myelofibrosis transforming into multiple subcutaneous monoblastoma--a case report].

A 83-year-old man was diagnosed with primary myelofibrosis based on the presence of leukoerythroblastosis, splenomegaly, chromosome 46 XY, a dry tap bone marrow aspiration and fibrosis on bone marrow biopsy, when he was admitted for herpes zoster in June 1987. He was admitted for a second time with multiple subcutaneous tumors over his entire body in July, 1989. He had mild splenomegaly, but no hepatomegaly nor lymphadenopathy. Laboratory tests were as follows: RBC 214 x 10(4)/microliters, Hb 5.1 g/dl, Ht 17.7%, WBC 3,200/microliters with leukoerythroblastosis, platelets 11.6 x 10(4)/microliters, s-lysozyme 251 micrograms/ml, u-lysozyme 770 micrograms/ml, NAP ratio 98%, score 278. Bone marrow aspiration resulted in a dry tap. Bone marrow biopsy showed marked fibrosis. Histologic examination of subcutaneous tumor biopsy specimens revealed a diffuse infiltration of monocytes with flexuous nuclei. These cells were positive for alpha-naphtyl butyrate esterase stain, and negative for peroxidase, alpha-naphtol ASD chloroacetate esterase stain and platelet glycoprotein IIb/IIIa stain (APAAP). Ultrastructurally, these cells were mostly monocytes and promonocytes, while phenotypically, CD11b, CD13, CD14, CD33 and HLA-DR were positive. These date indicated that the subcutaneous tumors originated from monocytes.