Int. J. Oral Maxillofac. Surg. 1987: 16:108-111 (Key words: myelofibrosis; chloroma; mandible; leukemia) Acute myelofibrosis and multiple chloromas of the mandible and skin MANSOOR N. SALEH, BRAD RODU, JOSEF T. PRCHAL, ELIAS ROMERO DE LEON Department of Pathology, University of Alabama Schools of Medicine and Dentistry, University of Alabama at Birmingham, Birmingham, Alabama ABSTRACT -- Acute myelofibrosis is a rare clinical entity characterized by severe marrow fibrosis and peripheral blood pancytopenia. It may be very closely related to and has been considered synonymous with megakaryocy- tic leukemia. Chloroma is also a rare entity composed of a localized collection of immature myeloid cells and is associated with a known or covert leukemia. A patient presenting with a rare combination of acute myelofibrosis, megakaryocytic leukemia and multiple chloromas of the mandible and skin, are described. Although presenting a diagnostic chal- lenge, their combination in one patient aids in the understanding of the myeloproliferative process. To our knowledge, this is the 3rd case of chloroma involving the oral osseous structures. (Accepted for publication 15 March 1986) Acute myelofibrosis is a rare clinical entity characterized by severe marrow fibrosis and peripheral blood pancytopenia. A leukoer- ythroblastic picture is seen on peripheral smear, but without the red cell changes (e.g., tear-drop cells) or the splenomegaly associ- ated with idiopathic chronic myelofibro- sis 2,~2. The syndrome may be synonymous with megakaryocytic leukemia ~,8. We present a case of an elderly patient, who initially presented with the clinical pic- ture of acute myelofibrosis with signs of megakaryocytic leukemia. She subsequently developed a mandibular lesion, as well as several subcutaneous nodules, which con- sisted of an accumulation of blasts (diag- nosed as chloromas) as well as fibrosis. Case presentation The patient, a 62-year-old white female, was in good health until 1 year prior to presentation when she developed symptoms of anorexia, weight loss, and dyspnoea upon minimal exer- tion. The patient was seen by a local physician with a hematocrit of 10% (0.101) and was treated with vitamin B~2 injections, yeast extract and blood transfusions. A gastrointestinal examina- tion for possible bleeding sites was negative. Physical examination at the time of referral to the consulting internist revealed a pale female with bilateral pitting edema of the lower extrem- ities, but an otherwise completely normal exam- ination, except for a pansystolic murmur heard all over the precordium, but most pronounced over the aortic area. No organomegaly was noted on examination. Laboratory studies revealed he- moglobin 5.6 g/dl, white blood cells 2.3 x 109/1