Histology/Histopathology

• Gross:  smooth surface
• Histo: diffuse fibrosis
• 1. calcified ova (portal and periportal areas)
• 2. granuloma
• 3. lymphocyte

• focus of chronic infeciton
• microscopic aggregation of macrophages
• epithelial-like cells surround by collar of mononuclear leukocytes.
• Giant cells: older granuloma, energy of fibroblasts and CT with epitheloid cells

Epitheloid macrophages fuse forming multinucleate giant cells (secretory cells) present in chronic granulomatous formation

• Types:
• a. foreign body type - central group of nuclei
• b. Zanghan's giant cell - tuberculosis, horseshoe formation around periphery

• Granulomatous inflammation:
• -  histiocytes (activated macrophages) differentiate to epitheloid macrophages then fuses forming MN giant cell

• 1. EI
• 2. Stasis/turbulance of blood flow
• 3. hypercoagability

• Example clinical: chest pain, dyspnea, cyanosis, RF
• Histo: dilated alveoli lined with eosinophilic matrix, congested alveolar capillaries, edema, amorphous proteinous materal, MN cells and macrophages

• Example clinical: DOB, fever, pneumonitis, mild effusion, CPA
• Gross: multiple petichial hemorrhage, consolidation
• Histo:  --
• 1. pulmonary congestion of BV, pulmonary edema (pinkis, homogenous, granular), inflammatory infiltrates
• 2. alveolar hemorrhage

• Case of:  chornic hypertrophic tonsilitis
• Example clinical: 26F, pain on swallowing, high grade fever at least 2x/mo for 7 conseq years
• Gross: tonsils enlarged and rubbery
• Histo: reactive lymphoid follicular hyperlplasia overlying squamous epithelium
• a. lining epithelium
• b. lymphoid follicles and germ centers
• c. diffuse type of cells in lymphoid tissue

^{read on adaptive immunity}

Case of: 52 year old, enlarged thyroid, elevated TSH, low T4 and FT3, tremor, palpitation

• Robbin: progressive depletiono f thryoid epithelial cells (thyrocytes) replace byMN cell infiltrates and fibrosis
• Gross: dark brown and nodular
• Histo: 
• 1. thyroid follicles
• 2. focal lymphoid proliferation
• 3. hurthle cells

• Autoimmune thyroiditis
• - throid acini with diffuse infiltrates of lymphoid and plasma cells
• - mononuclear inflammatory infiltrates
• - lymphoid follicles with germinal centers

• Oncocytic/Hurthle cells
• - thyroid epithelial cells
• - eosinophilic granular cytoplasm with slightly enlarged nuclei

Gross: nonencapsulated with prominent fibrosis

Histo: fibrosis, lymphcytes, macrophages, giant cells

• Mechanism:
• a.  APC antigen: CD4+, CD8+ cause cytokine release
• b.  T cell mediated CD8+ killing of macrophage

• Delayed type reaction: GRANULOMA 
• a. perivascular infiltrates of T cells and macrophages
• 2. replaced by macrophages (epitheloid cells)