Etiology, pathogenesis:
Histology:
Bone marrow is normo- or hypercellular with normal or reactively changed hematopoiesis depending on the inciting agent. The marrow also contains increased numbers of polyclonal small round lymphocytes, usually with the majority of T cells. Sometimes lymphocytes form aggregates, which are well circumscribed and may even contain germinal centres. These benign aggregates are localized in the centre of the intertrabecular space, they do not occur in peritrabecular locations.
Etiology, pathogenesis:
Histology:
Bone marrow is normo- or hypercellular with normal or reactively changed hematopoiesis depending on the etiological agent. The marrow also contains increased numbers of perivascular mature plasma cells These cells are polyclonal (the kappa:lambda ratio is normal, i.e. 2:1).
Etiology, pathogenesis:
Histology:
Bone marrow is hypo-, normo- or hypercellular with normal or reactively changed hematopoiesis depending on the offending agent. Small granulomas consisting of epithelioid histiocytes are also dispersed throughout the marrow. Langhans-type giant multinucleated cells may also occur. Granulomas sometimes blend or even necrotize in the centre. Sometimes, peripheral lymphoplasmacytic cellulization is present.
Etiology, pathogenesis:
Histology:
Bone marrow is hypo-, normo- or hypercellular with reactively changed hematopoiesis and possibly slight dysplastic changes. It also contains an increased number of macrophages with abundant soft granular eosinophilic cytoplasm in which erythrocytes and other hematopoietic cells are phagocytosed (erythrophagocytosis, hematophagocytosis).
Pictures
Hemophagocytic syndrome, bone marrow:
Hemophagocytic syndrome, bone marrow, HE 100x (72631)Hemophagocytic syndrome, bone marrow, CD68 100x (72630)
Introduction:
Certain storage diseases affect bone marrow (and other tissues). Some of the most common bone marrow storage diseases are Gaucher's and Niemann–Pick diseases.
Etiology, pathogenesis:
A congenital deficiency in lysosomal glucocerebrosid-beta-glucosidase causing glukocerebroside accumulation in macrophages in liver, spleen and bone marrow.
Clinical signs:
Histology:
Bone marrow is hypercellular with suppressed hematopoiesis and an increased number of large macrophages. These so-called Gaucher cells have an eccentric nucleus and abundant cytoplasm with a striated appearance which resembles folded cigarette rolling paper.
Etiology, pathogenesis:
Congenital deficiency in lysosomal sphingomyelinase, which results in sphingomyelin, cholesterol and glycolipid accumulation in macrophages in liver, spleen, bone marrow, hepatocytes and CNS cells.
Clinical signs:
Pancytopenia caused by suppression of hematopoiesis in the marrow. Other symptoms vary, depending on other affected organs.
Histology:
Bone marrow is hypercellular with suppressed hematopoiesis and an increased number of large macrophages, which have eccentric nuclei and abundant foamy cytoplasm.