Density Distribution and Size of Megakaryocytes in Inflammatory Reactions of the Bone Marrow (Myelitis) and Chronic Myeloproliferative Diseases

Abstract

Morphometric evaluation was performed on semi‐thin sections of core biopsies of the bone marrow and included 20 cases of each group of diseases besides control specimens. (i) Hyperergic myelitis of rheumatic origin. (ii) Chronic granulocytic leukaemia (CGL). (iii) Polycythaemia vera (P. vera). (iv) Chronic megakaryocytic‐granulocytic myelosis (CMGM). (v) Myelofibrosis or osteomyelosclerosis (MF/OMS). The following classification of megakaryopoiesis was applied: normal megakaryocytes; giant forms; microforms; intussusceptions; cytoplasmic fragments; naked nuclei. The density distribution shows an increase of megakaryocyte number in those 5 different marrow disorders, ranging from about 13/mm2 in the normal sample up to 65 cells/mm2 in MF/OMS. Microforms are most frequently encountered in CGL, whereas giant megakaryocytes, intussusceptions and many cytoplasmic fragments characterize P. vera, CMGM and MF/OMS. Our measurements suggests 3 distinct categories of bone marrow lesions with corresponding alterations of the megakaryopoiesis: (i) myelitis and CGL; (ii) P. vera; (iii) CMGM and MF/OMS.

The role of apoptosis in megakaryocytes and platelets

“…The evidence led them to suggest that once shedding has occurred, megakaryocytes undergo apoptosis and phagocytosis by macrophages. Interest in denuded megakaryocyte nuclei initially centred on their increased frequency in conditions such as human immunodeficiency virus (HIV) infection and myelodysplastic syndromes (Thiele et al , ; Zucker‐Franklin et al , ; Hatfill et al , ; Zauli et al , ). However, the identification of thrombopoietin (TPO) and development of primary megakaryocyte culture systems led to the observation that peak platelet production by mature megakaryocytes ‘corresponded to the onset of apoptosis’ (Zauli et al , ).…”

Infection and Reactive Changes

“…However, haemophagocytosis and granuloma for-However, the normal topographical arrangement of granulopoiesis is retained, with the more immature cells (mainly promyelocytes) found predominantly in the paratrabecular region [16] . Megakaryocytes are often increased in number [17] ; they are morphologically normal, but there may be an increase in ' bare ' megakaryocyte nuclei and increased emperipolesis. Erythropoiesis is often reduced although morphologically normal.…”

Bone marrow trephine biopsy: anterior superior iliac spine versus posterior superior iliac spine

“…The sites most commonly chosen for puncture have been the posterior superior iliac spine (PSIS) (Ellis et al 1964;Jamshidi & Swain 1971;Dombernowski et al 1974;Islam 1982;Pasquale & Chikkappa 1986;Hyun et al 1988) and the anterior superior iliac spine (ASIS) (Burkhardt 1971; Duhamel M.T. Hernandez-Garcia et al 1974, Henon et al 1976Hernandez Nieto & Rozman 1980;Thiele et al 1983;Woessner 1990;Pereira et al 1990). A Jamshidi needle is not uncommonly used to perform BMB of the ASIS.…”