Differential Diagnosis: Peripheral Lymphadenopathy in Cats

Following are differential diagnoses for cats presented with peripheral lymphadenopathy.

• Neoplastic

  • Lymphoproliferative

    • Lymphoma

      • T-cell-rich B-cell lymphoma¹ 

      • Hodgkin-like lymphoma²

  • Metastatic neoplasia (common causes)

    • Carcinoma (eg, mammary gland carcinoma, oral squamous cell carcinoma)

    • Mast cell tumor

• Reactive

  • Infectious 

    • Systemic fungal infection

      • Blastomycosis (Blastomyces dermatitidis)

      • Histoplasmosis (Histoplasma capsulatum)

      • Coccidioidomycosis (Coccidioides immitis)

      • Cryptococcosis (Cryptococcus neoformans)

      • Sporotrichosis (Sporothrix schenckii)

    • Mycobacteriosis (Mycobacterium avium complex; Mycobacterium bovis, Mycobacterium microti-like)

    • Vector-borne disease (coinfection is common) 

      • Ehrlichiosis (Ehrlichia spp)

      • Cytauxzoonosis (Cytauxzoon felis)

      • Leishmaniasis³ (Leishmania spp)

      • Tularemia⁴ (Francisella tularensis)

      • Hepatozoonosis (Hepatozoon spp)

      • Plague (Yersinia pestis)

      • Bartonellosis (Bartonella henselae)

    • Toxoplasmosis (Toxoplasma gondii)

    • Hemotrophic mycoplasma⁵ (Mycoplasma spp)

    • Retrovirus 

      • FeLV

      • FIV

• Inflammatory or immune related 

  • Autoimmune lymphoproliferative syndrome of British shorthair cats<sup6 sup> 

• Drug reaction

  • Phenobarbital-induced pseudolymphoma<sup7 sup> 

  • Zonisamide-induced lymphadenopathy⁸ 

  • Methimazole<sup9 sup> 

• Idiopathic

  • Plexiform vasculopathy of cervical or inguinal lymph nodes¹⁰

  • Generalized lymphadenopathy resembling lymphoma¹¹

  • Distinctive peripheral lymph node hyperplasia of young cats¹²