Lymph node

• Section of a portion of the outer cortex of a lymph node
• showing the capsule, subcapsular sinuses, diffuse lymphoid tissue, and lymphatic nodules
• H & E stain
• Medium magnification

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Lymph node: sections

Figure A

• Section of a lymph node showing the cortex and the medulla & their primary components
• H & E stain
• Low magnification

Figure B

• (1) capsule
• (2) lymphoid nodule with germinative center
• (3) subcapsular sinus
• (4) intermediate sinus
• (5) medullary cords
• (6) medullary sinus
• (7) trabecula

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Lymph node: Medulla

Figure A

• Medullary cord of lymphoid nodule
• In addition to lymphocytes, this area contains many plasma cells (ARROWS)

Figure B

• Label 1: Medullary sinus
• Label 2: Medullary cord
• H & E Stain
• High magnification

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Lymph node: Medulla

Figure A

• A photomicrograph of the medulla of a lymph node
• The medullary sinuses are separated by medullary cords
• Lymphocytes clearly predominate in number over other cell types
• A blood vessel within a medullary cord is also seen
• H & E Stain
• Medium magnification

Figure B

• (1) Medullary cords
• (2) Medullary sinuses
•  

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Lymphoid nodule of the spleen

• Lymphoid nodule of the spleen
• Surrounded by red pulp
• Label 1: A germinating center
• Label 2: The (eccentric) central artery
• Which are characteristics of the spleen & are clearly visible
• 2 small sections of sheathed arteries are seen to the right of the nodule
• H & E stain
• Medium magnification

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Bone marrow: normal

• This is the appearance of a normal bone marrow
• Note the presence of:

1. megakaryocytes
2. erythroid islands
3. granulocytic precursors

• high magnification

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Bone marrow smear: Normal

• This is the appearance of a normal bone marrow smear
• Note the presence of:

1. megakaryocytes
2. erythroid precursors
3. granulocytic precursors

• High magnification

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Spleen: Section

• The capsule is seen sending the trabeculae to the interior of the organ
• The red pulp occupies most of the microscopic field
• Note the white pulp with its arterioles
• Pirosirius stain
• Low magnification

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Spleen: Section

Figure A

• Section of spleen showing the red pulp (most of microscopic field) and a component of the white pulp – a periarterial lymphatic sheath (PALS) surrounding a central artery
• Small sections of trabeculae are present in the red pulp
• H & E stain
• Low magnification

Figure B

• (1) PALS
• (2) central artery
• (3) red pulp
• (4) sinusoids

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Blood smear

• The RBCs here are normal
• Have a zone of central pallor about 1/3 size of the RBC
• The RBCs demonstrate minimal variation is size (anisocytosis) and shape (poikilocytosis)
• In the center of the field: A band of neutrophil (LEFT) and segmented neutrophil (RIGHT)

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Blood smear

• In the center of the field: eosinophil with a bilobed nucleus & numerous reddish granules in the cytoplasm.
• Just underneath eosinophil: small lymphocyte
• Eosinophils can increase with: allergic reactions & parasitic infestations

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Blood smear

• In the center of the field: basophil with a lobed nucleus (like PMNs) & numerous coarse, dark blue granules in the cytoplasm
• Infrequent in a normal peripheral blood smear
• Significance is uncertain
• Left: Band neutrophil
• Right: Large activated lymphocyte