17 - Lymphoid Tissue Cytology Flashcards
Indications for sampling peripheral lymph nodes
- Lymphadenomegaly
- Abnormal shape or consistency
Indications for sampling spleen
- Splenomegaly
- Abnormal shape, consistency, or presence of mass
- Staging of neoplastic disease
Indications for sampling thymus
- Abnormal shape, consistency, or presence of mass (mediastinal)
Lymph node aspirates
- Peripheral lymph node: palpate and immobilize with one hand
- Internal: often US guided
- Use 22 or 25 gauge needle and 6-12mL syringe
FNA vs. FNNA
- Your choice
- FNNA: might help limit blood contamination and might increase yield in some cases
Making a smear
- Spray onto slide near frosted end
- GENTLY slide over slide smear technique
- If sufficient liquid obtained, put in EDTA tube for cytospin smear
- If biopsy, make impression smears before putting tissues into formalin
Smear handling
- air dry quickly: no need to heat fix
- stain and examine one slide in house: ensure diagnostic sample
- avoid humidity and extreme temperatures
- ship to lab in slide holder
- do NOT ship together with formalin-fixed tissues
Smear evaluation: low magnification
- cellularity
- intactness of cells
- blood contamination
- extracellular material and background
- *heterogeneity/homogeneity of lymphocytes=PRIMARY CELL POPULATION
- Inflammatory cells
- Foreign material/cells
Smear evaluation: high magnification – oil
- Lymphocytes
o Nuclear features: shape, chromatin pattern, nucleoli
o Cytoplasmic features: colour, granules/vacuoles, perinuclear clearing
o Mitotic figures: normal vs. bizarre - ID of any non-lymphoid cells
What are some lymph node cytology differentials?
- non-diagnostic sample
- normal lymph node
- reactive/hyperplastic lymph node
- lymphosarcoma/lymphoma (ALL ARE MALIGNANT)
- lymphadenitis (inflammation)
- metastatic neoplasia
What are some pitfalls with lymph node cytology?
- Normal-sized lymph nodes: can be hard to aspirate
- Perinodal fat: might just be grabbing fat and not the lymph node
- Salivary gland: can be confused with a lymph node enlargement
- Cell fragility/rupture
What is your diagnosis?
-normal
What is your diagnosis?
-ruptured cells
*purple=screaming nuclear material!
>non-diagnostic sample
-clear vacuoles=FREE fat
What is your diagnosis?
-peridonal fat
What is your diagnosis?
-salivary gland
>foamy
>RBCs are lined up (wind rows): saliva was pulled into the long strands
Reactive vs. lymphosarcoma
- Can be challenging
- Determined by assessing heterogeneity vs. homogeneity of lymphocytes
o Based on lymphocyte size
o **Heterogeneity=normal/reactive
o **Homogeneity=lymphosarcoma
o Different than other cell types
Normal lymph node
- HETEROGENOUS population of lymphocytes
o Small lymphocytes: 75-95%
o Medium lymphocytes: 5-15%
o Large lymphocytes: 5%
o Macrophages
o Plasma cells
o Occasional neutrophils, eosinophils, mast cells
o Rarely submitted
Reactive or hyperplastic lymph node
- HETEROGENOUS population of lymphocytes
o Small lymphocytes: 70-80%
o Medium and large lymphocytes: 20-30%
o Increased numbers of PLASMA CELLS
o May also see Mott cells with Russel bodies
Plasma cell appearance
- Eccentric nucleus
- Condensed chromatin
- Deeply basophilic cytoplasm
- Golgi zone
Using RBC ‘micrometer’ to determine lymphocyte size
- Small=1-1.5x diameter of RBC
- Medium: 2-2.5x diameter of RBC
- Large: >3x diameter of RBC
What is this?
-plasma cell
What is this?
- Mott cells with Russel bodies (still a plasma cell)
*no signifance=just the same as a plasma cell significance
What are some causes of reactive lymph nodes?
- Part of local or general immune response
- Pathology in the tissue drained by the node
o Dental disease
o Skin disease
Lymphosarcoma
- HOMOGENOUS population lymphocytes
- Medium to large lymphocytes PREDOMINATE: >50%
- Round to irregular nuclei
- Dispersed chromatin
- Deeply basophilic chromatin
- Cytoplasmic vacuoles/granules
- Large, multiple, bizarre nucleoli
- Increased mitotic figures
- Extracellular cytoplasmic fragments
What are some features NOT sued to assess malignancy in lymphocytes?
- High N:C ratio
- Anisocytosis
- Anisokaryosis
Inflammatory: ‘categories/types’
- Neutrophilic
- Macrophagic
- Mixed neutrophilic and macrophagic
- Eosinophilic
Inflammatory
- Can be primary (ex. infectious disease)
o Ex. blastomycosis: expect mixed neutrophilic and macrophagic inflammation - Can be secondary (ex. draining a site of inflammation)
o Ex. allergic skin disease (could see eosinophils in draining lymph node)
o Ex. dental disease
Diagnosis?
blasto organism
-neutophils, macrophages
-small lymphoid cells
Diagnosis?
marked eosinophilic inflammation:
Diagnosis?
-mast cells
-eosinophils
Neoplasia metastatic to lymph node
- Local or distant primary neoplasm
- May be first evidence of neoplasia or part of staging known neoplasia
- May be impossible to confirm lymph node
o Neoplasia may completely efface lymph node
o No lymphocytes present
