Chapter 13: Leukopenia, Reactive Proliferation of White Cells and Lymphoid Neoplasms Flashcards
How to hypoplastic states vs. hyperplastic/neoplastic states affect the ratio of fat cells:hematopoietic cells in the bone marrow when biopsied?
- Hypoplastic = proportion of fat cells is >>> increased
- Hyperplastic = the fat cells often dissapear
Where do the definitive hematopoietic stem cells (HSCs) arise from during development?
Mesoderm of the intraembryonic aorta / gonads/ mesonephros region
Where do HSCs migrate to during the 3rd month of embryogenesis, which becomes the chief site of blood cell formation until shortly before birth?
Liver
Where is the hematopoietically-active tissue found in adults?
Bone marrow of axial skeleton
In adults, where are BM biopsies typically collected from?
PSIS
Which cells lie next to bone marrow sinusoids and extend cytoplasmic processes that bud off into the bloodstream to produce platelets?
Megakaryocytes
What is the most common cause of clinically significant neutropenia (agranulocytosis)?
Drug toxicity
What are characteristics findings of the damage due to infections seen in agranulocytosis?
Ulcerating necrotizing lesions of the gingiva, floor of mouth, buccal mucosa, and pharynx
Neutropenic patients are at high risk for deep fungal infection caused by which 2 organisms?
Candida and Aspergillus
What is the most distinctive symptom of Franklin Disease (aka γ-heavy chain disease)?
Palatal edema
Characteristic findings of the LN’s associated w/ acute nonspecific lymphadenitis?
- Enlarged and painful
- Large, reactive, germinal centers containing numerous mitotic figures
What are 3 morphological features which favor a reactive (non-neoplastic) follicular hyperplasia?
- Preservation of LN architecture
- Marked variation in the shape and size of follicles
- Presence of frequent mitotic figures, phagocytic macrophages (tingible body), and recognizable dark and light zones
Infection caused by what bacteria is associated with lymphocytosis?
Bordetella pertussis
What is the pathogenesis of hemophagocytic lymphohistiocytosis (aka macrophage activating syndrome)?
Systemic activation of macrophages and CD8+ cytotoxic T cells
What is the most common trigger for hemophagocytic lymphohistiocytosis (HLH)?
Infection, particularly EBV
