フルニエ壊疽に類似した陰茎壊疽性膿皮症の1例

Abstract

77歳男性.患者は限局性前立腺癌に対する外照射および高線量率組織内照射による放射線療法後の経過観察中, 陰茎痛および発熱が出現した.陰茎背部に発赤, 硬結を認め, レボフロキサシンの経口投与を行ったが, 同部の自壊, 排膿を認め, 緊急入院となった.入院時, 陰茎背側は腫大, 硬化し, 潰瘍形成を伴っており, 細菌感染による炎症性病変と判断し, 病変部のデブリドメンおよびメロペネム三水和物, メシル酸パズフロキサシンの点滴静注, ガンマグロブリン製剤の投与を行ったが, 疼痛の増強, 病巣の拡大がみられた.膿汁の細菌培養の結果, 陰性であることが判明し, 非細菌性病変を考え, ステロイド投与を開始したところ, 疼痛および潰瘍性病変は改善した.以上より, 最終的に陰茎壊疽性膿皮症の診断に至った

We report a case of pyoderma gangrenosum of the penis presenting as Fournier's gangrene. A 77-year-old man who had undergone radiotherapy for localized prostate cancer 16 month earlier, presented with penile pain and fever. Symptoms began with erythema and induration on the dorsal surface of the penile shaft followed by spontaneous purulent drainage with severe pain. Magnetic resonance imaging was unremarkable except for swelling of the penile skin. Biopsy of the ulcerative penile lesion demonstrated a nonspecific inflammation without vasculitis or malignancy. Despite broad-spectrum antibiotics and debridement, the penile lesion extended and new satellite lesions developed as pustules on the glans. Since cultures were negative for aerobic and anaerobic bacteria, a course of intravenous prednisolone was then initiated at 100 mg/day. Within 24 hours the temperature normalized, progression of the penile lesions stopped and became convalescent. The steroid was then tapered and discontinued. The penile lesions healed slowly during the subsequent 1-month period. Based on the clinical course and histopathological findings as well as exclusion of other ulcerative conditions, a diagnosis of pyoderma gangrenosum was made. Penile involvement of this non-infectious ulcerating skin disease has rarely been reported. Pyoderma gangrenosum affecting the penile skin, such as that in present case, may show a similar presentation as Fournier's gangrene. Prompt differential diagnosis is mandatory since effective management for each processes is markedly different.