Kimura Disease



Kimura Disease


C. Cameron Yin, MD, PhD










Lymph node and perinodal soft tissue involved by Kimura disease. This field reveals hyperplastic lymphoid follicles, marked eosinophilia, and fibrosis.






Lymph node involved by Kimura disease. This field shows marked replacement of the interfollicular regions by lymphocytes and eosinophils. A reactive follicle is present image.


TERMINOLOGY


Abbreviations



  • Kimura disease (KD)


Synonyms



  • Kimura lymphadenopathy


  • Eosinophilic lymphogranuloma


  • Eosinophilic lymphoid follicular hyperplasia


Definitions



  • Rare chronic inflammatory disorder of unknown etiology



    • Commonly occurs in head & neck region and involves subcutaneous tissues and lymph nodes


  • Unrelated to angiolymphoid hyperplasia with eosinophilia (ALHE)



    • Historically, these entities were once considered to be the same


ETIOLOGY/PATHOGENESIS


Infectious Agents



  • History and histologic findings suggest infectious etiology



    • No definite pathogen has been identified


Other Proposed Causes



  • Allergy


  • Autoimmunity


CLINICAL ISSUES


Epidemiology



  • Age



    • Mainly occurs in young adults



      • Peak age of onset in 3rd decade


  • Gender



    • Predominantly males


  • Ethnicity



    • Asians are most commonly afflicted


    • Named after T. Kimura from Japan who reported a case in 1948


Site



  • Usually in head & neck region


  • Involves deep subcutaneous tissues



    • Regional lymph nodes


  • Often involves major salivary glands



    • Parotid


    • Submandibular


Presentation



  • Nontender masses in head & neck



    • Most often in periauricular region


  • Rarely patients have generalized lymphadenopathy


  • Systemic symptoms are uncommon


  • Nephrotic syndrome may occur in up to 60% of patients


Laboratory Tests



  • Peripheral blood eosinophilia almost invariable


  • Elevated serum IgE level


  • Elevated erythrocyte sedimentation rate (ESR)


  • Imbalance between Th1 and Th2 cytokines with



    • Increased TNF-α, IL-4, IL-5, IL-13, etc.


Natural History



  • Insidious onset


  • Slow-growing mass



    • Interval from onset of swelling to presentation may be several years


    • Often persists unchanged for years


Treatment



  • Adjuvant therapy



    • Radiation therapy usually yields best outcome


    • Patients treated with surgical excision &/or steroid therapy have high rate of recurrence




      • Advantages of surgical excision: Short treatment duration and provides tissue for histopathologic diagnosis


Prognosis



  • Indolent clinical course


  • Recurrence after excision is common


IMAGE FINDINGS


General Features



  • Ultrasound, CT, or MR scans are useful for determining extent of disease


  • Combination of ultrasonography and MR has been shown to have high diagnostic value



    • Hypoechoic center and hyperechoic margin with enriched blood vessels on ultrasonography and Doppler


    • Hypointensity replaces normal hyperintense subcutaneous fat on MR


    • Lymph nodes are enlarged with well-defined outline


  • CT scan shows nonspecific findings


MICROSCOPIC PATHOLOGY


Histologic Features



  • Lymphoid infiltrate in deep subcutis



    • Formation of follicles with germinal centers


    • Accompanied by many eosinophils, plasma cells, and mast cells



      • Eosinophilic microabscesses can be present


    • Vascular hyperplasia


  • Lymph nodes show preserved but distorted overall architecture with



    • Hyperplastic follicles with well-formed germinal centers and mantle zones


    • Deposition of IgE in germinal centers forms hyaline proteinaceous material


    • Eosinophilia



      • Eosinophilic microabscesses and eosinophilic follicle lysis


      • Involvement of perinodal soft tissues


    • Necrosis (±); usually not extensive


    • Vascular proliferation in interfollicular regions



      • Endothelial cells lack cuboidal/polygonal shape with cytoplasmic vacuoles


      • i.e., endothelial cells lack “hobnail” or “tombstone” appearance (seen in ALHE)


    • Stromal and perivascular sclerosis


Cytologic Features



  • Fine needle aspiration (FNA) yields polymorphous cell population with many eosinophils



    • Difficult to establish diagnosis of KD based on FNA findings alone


ANCILLARY TESTS


Immunohistochemistry



  • IgE deposits in the germinal centers can be shown by immunohistochemistry or immunofluorescence


  • Polytypic B cells and normal T cells


Molecular Genetics



  • No evidence of monoclonal gene rearrangements


  • No known translocations or oncogene abnormalities


  • No evidence of infectious organism identified


DIFFERENTIAL DIAGNOSIS


Angiolymphoid Hyperplasia with Eosinophilia (ALHE)

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Kimura Disease
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