Canis ISSN: 2398-2942

Cytology: lymph node aspirate

Synonym(s): Fine needle aspiration

Contributor(s): Kathleen P Freeman, Karen Gerber


  • Lymph node aspirate cytology is a useful tool to identify the underlying cause of lymphadenopathy without the need for anesthesia.
  • Fine needle aspirate cytology can distinguish between hyperplasia, lymphoma Lymphoma , lymphadenitis Lymphadenopathy , infectious agents, reactive nodes and metastatic neoplasia.


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  • Aspirates can be examined immediately in practice by a veterinarian experienced in cytology.
  • Widely available at commercial laboratories.



  • Excellent if representative specimen obtained.


  • Excellent if representative sample obtained.

Predictive value

  • Tumor metastasis in dogs and cats with solid tumors, can reliably be identified by cytological examination with 100% sensitivity and 96% specificity (Langenbach A et al, 2001).

Technique (intrinsic) limitations

  • In patients with multicentric lymphadenopathy it is useful to aspirate more then one lymphnode as submandibular lymphnodes are often very reactive and prescapular lymph nodes may contain large amounts of cell free fat which increases the fragility of lymphocytes.Tissue architecture is not represented in cytological preparations, may require confirmation by histology.

Technician (extrinsic) limitations

  • Incorrect sampling tools or technique.
  • Poor slide preparation, ie cells poorly distributed or ruptured.
  • Inexperience in interpretation.

Result Data

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Further Reading


Refereed papers

  • Recent references from VetMed Resource and PubMed.
  • Amores-Fuster A, Cripps P, Graham P, Marrington A M & Blackwood L (2015) The diagnostic utility of lymph node cytology samples in dogs and cats. JSAP 56, 125-129 PubMed.
  • Langenbach A et al (2001) Sensitivity and specificity of methods of assessing the regional lymph nodes for evidence of metastasis in dogs and cats with solid tumours. JAVMA 218(9), 1424-1428 PubMed.
  • Cytology of lymphoid tissue (1987) Comp Cont Ed Prac Vet 9, 104-111.

Other sources of information

  • Raskin R A & Meyer D J (2001) Atlas of Canine and Feline Cytology. 1st edn, W B Saunders Company publication, Pennsylvania, USA.
  • Baker R & Lumsden J H (2000) Colour Atlas of Cytology of the Dog and Cat. 1st edn. Mosby publications, Missouri, USA.
  • Cowell R L, Tyler R D & Meinkoth J H (1999) Diagnostic Cytology and Hematology of the Dog and Cat. 2nd edn. St. Louis: Mosby.
  • Duncan J R, Prasse K W & Mahaffey E A (1994) Veterinary Laboratory Medicine - Clinical Pathology. 3rd edn. Iowa: Iowa University Press.