Kimura Disease



Kimura Disease


C. Cameron Yin, MD, PhD





Key Facts


Terminology



  • Chronic inflammatory disease that affects subcutaneous tissue and regional lymph nodes


Etiology/Pathogenesis



  • Unknown; infectious cause suspected


Clinical Issues



  • Mainly in young Asian males


  • Head & neck region



    • Nontender subcutaneous masses


    • Regional lymphadenopathy


  • Peripheral blood eosinophilia and elevated serum IgE


  • Benign clinical course; recurrence common


Microscopic Pathology



  • Skin



    • Typically located in deep subcutaneous tissue


    • Reactive follicles with prominent germinal centers


    • Eosinophilia and vascular hyperplasia


  • Lymph nodes



    • Hyperplastic follicles


    • Eosinophilia with eosinophilic microabscesses


    • Stromal and perivascular sclerosis


Ancillary Tests



  • Immunophenotypic studies



    • IgE deposits in germinal centers


    • Polytypic B cells and normal T cells


Top Differential Diagnoses



  • Angiolymphoid hyperplasia with eosinophilia


  • Langerhans cell histiocytosis


  • Dermatopathic lymphadenopathy


  • Parasitic infection






Low-power view shows a lymph node and perinodal soft tissue involved by Kimura disease. This field reveals hyperplastic lymphoid follicles image, marked eosinophilia, and fibrosis.






A lymph node involved by Kimura disease is pictured with 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 2nd and 3rd decades


  • 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


Laboratory Tests



  • Peripheral blood eosinophilia almost invariable


  • Elevated serum IgE level


  • Elevated erythrocyte sedimentation rate (ESR)


  • Imbalance between Th1 and Th2 cytokines



    • 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


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


  • Some may have allergic conditions such as urticaria or eczema



Treatment



  • Adjuvant therapy



    • Surgical excision and steroid therapy are the most widely used treatments



      • Both have a high rate of recurrence



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


    • Local irradiation yields the best outcome



    • Not advocated in children due to the impact on growth and potential risk of malignancy


Prognosis



  • Indolent clinical course


  • Recurrence after excision and steroid therapy 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, e.g., “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 an infectious organism


DIFFERENTIAL DIAGNOSIS


Angiolymphoid Hyperplasia With Eosinophilia (ALHE)



  • ALHE has a number of other names



    • Epithelioid hemangioma is probably best name



      • Lesion is thought to be benign vascular neoplasm


    • Other names



    • Histiocytoid hemangioma


    • Pseudo- or atypical pyogenic granuloma



    • Inflammatory angiomatous nodule


    • Intravenous atypical vascular proliferation


  • Occurs more often in



    • Caucasians


    • Young to middle-aged adults


  • Presents as multiple papules or nodules



    • Usually occurs in head and neck region


    • Common around ear


  • Peripheral blood eosinophilia occurs in ˜ 15% of ALHE patients


  • Histologic findings of ALHE differ from Kimura disease as follows



    • Located in superficial dermis


    • Lesion has low-power lobular pattern of capillary or medium-sized blood vessels


    • Hypertrophic cuboidal/polygonal endothelial cells



      • Protrude into or occlude vascular lumina


      • Described as “hobnail” or “tombstone” appearance


    • Lesion can be located within large blood vessel


    • No lymph node involvement


  • Local recurrence can occur in ˜ 33% of patients


Langerhans Cell Histiocytosis

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

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