Toxoplasma Lymphadenitis

Toxoplasma Lymphadenitis

Carlos E. Bueso-Ramos, MD, PhD

Toxoplasma lymphadenitis. Note enlarged follicles with reactive germinal centers, clusters of epithelioid cells encroaching on lymphoid follicles, and monocytoid cells.

Hematoxylin and eosin stain shows a reactive germinal center with many centroblasts, tingible-body macrophages, and epithelioid cells encroaching into the germinal center from the right image.



  • Toxoplasmic lymphadenitis

  • Glandular toxoplasmosis

  • Piringer-Kuchinka lymphadenopathy


  • Inflammation of lymph node caused by infection by Toxoplasma gondii


Toxoplasma gondii Infection

  • T. gondii is protozoan that can invade many cell types

  • Cat is definitive host for sexual stage of reproduction

    • Trophozoites reproduce in intestinal epithelium

    • Oocysts are generated that are eliminated in feces

  • Humans and animals are intermediate hosts

    • Ingest oocysts from contaminated soil

    • Humans can ingest oocysts from undercooked meat

  • In humans and animals, oocysts are digested by digestive enzymes

    • Trophozoites are released into intestine

      • Organisms are carried by macrophages

      • Spread via lymphatics and blood vessels to internal organs

    • Within macrophages, trophozoites can multiply and become crescent-shaped tachyzoites

  • In immunocompetent patients, tachyzoites usually become segregated into cysts synthesized by host

    • Within cysts, organisms are slow-growing bradyzoites

    • Infection typically resolves

  • In immunodeficient patients, tachyzoites widely disseminate, causing acute infection



  • Incidence

    • Toxoplasmosis is common parasitic disease worldwide

      • More prevalent in warm and humid climates

    • In USA, toxoplasmosis is most common parasitic infection

      • 50% of USA citizens have serum antibodies to T. gondii: Evidence of chronic infection

    • T. gondii can be spread transplacentally from mother to fetus

      • 1 in every 1,000 live births in USA

      • ˜ 3,000 births are affected annually

      • Potential damage to fetus is greatest with infection in 1st trimester

    • Rarely, T. gondii infection can be transmitted via transplanted organ

    • Active infection may result from reactivation of earlier infection

      • Common in patients with cancers and diabetes mellitus

  • Age

    • Children and young adults most often affected

  • Gender

    • No sex preference


  • Lymph nodes are commonly affected

    • Posterior cervical lymph nodes are characteristic site

      • Often unilateral

    • Any group of lymph nodes can be involved

      • Other cervical, supraclavicular, occipital, parotid, intramammary regions

    • Generalized lymphadenopathy or hepatosplenomegaly can occur but is unusual


  • Asymptomatic infection is common in immunocompetent individuals

  • Mild illness also can occur manifested by malaise, fever, myalgia

  • Physical examination of lymph nodes

    • Tender or nontender

    • Firm but not rock hard

    • 0.5-3.0 cm

Laboratory Tests

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Toxoplasma Lymphadenitis
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