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Histopathological Diagnosis of Leprosy Type 1 Reaction with Emphasis on Interobserver Variation

I Sharma, M Kaur, A K Mishra

    Indian Journal of Leprosy
    |August 11, 2016
    PubMed

    Insights

    Diagnosing leprosy reversal reactions (RR) is challenging due to disparities between clinicians and pathologists. This study identifies key histopathological clues like dermal edema to improve RR diagnosis.

    Area of Science:

    • Dermatology
    • Pathology
    • Infectious Diseases

    Background:

    • Leprosy reversal reaction (RR) is an acute inflammatory complication of leprosy.
    • Discrepancies exist in diagnosing RR between clinicians and pathologists, compounded by inter-observer variability among pathologists.
    • There is a lack of universally agreed-upon diagnostic criteria for RR in histopathology.

    Purpose of the Study:

    • To assess clinicopathological correlation in diagnosing leprosy reversal reactions (RR).
    • To evaluate inter-observer agreement among pathologists in identifying RR histopathologically.
    • To identify reliable histopathological features for diagnosing RR.

    Main Methods:

    • 120 leprosy biopsies and H&E stained slides were reviewed by three independent pathologists.
    • Pathologists were blinded to clinical diagnosis and each other's assessments.
    • Histopathological findings were analyzed for correlation with clinical diagnosis and inter-observer agreement using Kappa statistics.

    Main Results:

    • Discordance between clinical and histopathological diagnoses ranged from 23.7% to 34.5%.
    • Consistent histopathological findings across observers included dermal edema, intragranuloma edema, and epidermal erosion.
    • Kappa statistics indicated good inter-observer agreement among the pathologists (κ = 0.61–0.83).

    Conclusions:

    • Leprosy reversal reactions (RR) may be underdiagnosed on histopathological examination.
    • Dermal edema, edema within the granuloma, and partial obliteration of the grenz zone by granuloma are reliable histopathological indicators for diagnosing RR.

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