尿管皮膚瘻周囲に発生した二次性乳房外Paget病

A case of secondary extramammary Paget's disease that occurred around the cutaneous stoma of ureterostomy

84歳男性。BCG膀胱注入療法後に前立腺部尿道にCIS再発を認め，膀胱全摘除術と両側尿管皮膚瘻造設術を施行された。その後，右皮膚瘻周囲に難治性皮膚炎を認めたため皮膚生検を施行した結果，異型細胞の表皮内増殖を認め，免疫染色にてGCDFP-15陰性，CK7陽性，CK20陽性であった。加えて右尿管洗浄尿の尿細胞診が陽性を認めたため，右上部尿路CISの再発に伴う二次性乳房外Paget病と診断した。

An 84-year-old man diagnosed with BCG-refractory carcinoma in situ of the prostatic urethra underwent total cystectomy and bilateral cutaneous ureterostomy construction. Over four years after the cystectomy, he had suffered from refractory dermatitis around the right cutaneous stoma. Because the lesion had not improved by conservative treatment, skin biopsy was performed. Histological findings of the biopsy specimen revealed intraepidermal proliferation of atypical cells. Immunostaining was negative for gross cystic disease fluid protein-15（GCDFP-15）and positive for cytokeratin7（CK7）and cytokeratin20（CK20）, respectively. Urine cytology from the right ureter was positive for malignancy. The patient was diagnosed as secondary extramammary Paget's disease with recurrent carcinoma in situ of the right upper urinary tract. Right retroperitoneoscopic nephroureterectomy and en-bloc excision of the skin lesion surrounding the cutaneous stoma was performed with skin transplantation using a skin-graft from the right thigh.