1. Eosinophilic Granuloma (Benign; pathologic fractures; increased LC in bone)
2. Folate Deficiency
3. Hemoglobin C
4. Bone Marrow
4.1. CD34+ Hematopoietic Stem Cell
4.1.1. Myeloid Stem Cell
4.1.1.1. Blasts (Delicate chromatin, increased cytoplasm).
4.1.1.1.1. Acute Myelogenous Leukemia (AML) [MPO+ --> Auer Rods (Condensed azurophilic granules --> DIC) , > 20% blasts]
4.1.1.1.2. Myelodysplastic Syndrome
4.1.1.2. Mature
4.1.1.2.1. Myeloproliferative Disorders
4.1.1.3. Langerhans Cell Histiocytes (Derived from Monocytes)
4.1.1.3.1. Langerhans Cells (in skin; CD1a+, S100+; tennis racket (Birbeck granules)
4.1.1.3.2. Types
4.1.1.4. RBC Disorders
4.1.1.4.1. Anemia
4.1.2. Lymphoid Stem Cell
4.1.2.1. Blasts
4.1.2.1.1. Acute Lymphoblastic Leukemia (ALL)
4.1.2.2. Mature
4.1.2.2.1. Chronic Lymphocytic Leukemia (CLL)
4.1.2.3. Plasma Cell Disorders (Dyscrasias)
4.1.2.3.1. Multiple Myeloma
4.1.2.3.2. Waldenstrom Macroglobinemia ( B Cell lymphoma w/ monoclonal IgM)
5. Lymph Nodes
5.1. Lymphadenopathy
5.1.1. Painful when draining acute infection (Acute lymphadenitis) & Painless with chronic inflammation
5.1.2. Folicular Hyperplasia (B-Cell) in rheumatoid, early HIV
5.1.3. Paracortex (Viral)
5.1.4. Sinus Histiocytes in Medulla (Cancer)
5.2. Lymphoma
5.2.1. Non-Hodgkin
5.2.1.1. Types
5.2.1.1.1. Small Cell
5.2.1.1.2. Intermediate Cell
5.2.1.1.3. Large Cell
5.2.1.2. 60% of Lymphomas; CD20+
5.2.2. Hodgkin
5.2.2.1. Types
5.2.2.1.1. Nodular Sclerosis (Most common forms, RS in Lacunar Cells)
5.2.2.1.2. Lymphocyte-rich (best prognosis)
5.2.2.1.3. Lymphocyte-depleted (worst prognosis)
5.2.2.1.4. Mixed Cellularity
5.2.2.2. Reed-Sternberg Cells; CD15, CD30; Multi-lobed B Cells