広汎なPaget病を伴った直腸粘液癌の1例―肛囲Paget様病変の組織発生

A Case of Rectal Carcinoma Accompanied by Extensive Extramammary Paget's Disease: Special considerations on the histological interrelationship

　直腸癌にPaget病変を伴うことは比較的まれなことであるが，なかでも肛門部周囲におけるPaget病変の組織発生論には議論の多い所である．われわれは今回，直腸粘液癌に伴発した広汎な肛門部周囲のExtramammary Paget's Disease（以下，EPDと略す）の1例を経験したのを機会に直腸癌とPaget病変との関連性を組織学的に検討したので，若干の考察を加えてここに報告する．

症例

　患　者：家婦，77歳

　主　訴：肛門部周囲瘙

痒感，肛門出血

　家族歴・既往歴：特記すべきことなし

　現病歴：生来健康，1973年12月頃より肛門部出血に気付き近医にて痔核を指摘され痔核摘除術を受けた（詳細不詳）．1974年2月初め頃より肛門部周囲の瘙

痒感を伴う湿疹に気付き，近医にて保存的治療を受けるも次第に増悪，1975年3月，某市立病院に転科して治療を継続した．同年5月頃より便秘気味になるとともに，排便時に出血を認めるようになった．同年9月10日，皮膚生検施行．肛囲EPDと診断された．同年10月8日，当大学皮膚科外来受診．入院精査の結果，直腸癌を指摘され当科に転科入院した．

　We have experienced a case of rectal carcinoma accompanied by extensive extramammary Paget's disease in the perianal region and the histopathological interrelationship was considered.

　The presented case is a 77-year-old female who suffered from the perianal skin lesion for two years. This turned out to be extramammary Paget's disease by the skin biopsy. During the evaluation of the rectal bleeding, the rectal tumor was found to be a mucinous carcinoma of the rectum by the biopsy. On October 28, 1975, abdomino-perineal rectal amputation was performed. The entire resected specimen was examined for the histological evaluation. The type of carcinoma was a well differentiated papillotubular, mostly mucinous adenocarcinoma, invading the adventitia and classified in the Dukes C. Lymph node metastasis was counted out 13/25. The tissue in the skin lesion contained scattered Paget's cells in the epidermis which were positive by Diastase ersistant PAS, Aldehydefuchsin, Mucicarmine and Alcian Blue stainings. The rectal carcinoma was also stained positive by them. The PAM starining demonstrated the invasion of the metastatic rectal carcinoma from the subcutaneous tissue to dermal layer. No Paget's cells were identified in the appendages of the skin.

　The histological examination of the rectal carcinoma and the extramammary Paget's disease demonstrated the following findings:

　1) The histological continuance between the rectal carcinoma and the extramammary Paget's disease existed in the dermal layer.

　2) Paget's cells were found in the dermal layer where the malignant cells of the rectal carcinoma infiltrated up beyond the basal membrane of the epidermis.

　According to the above, the pathogenesis of the extramammary Paget's disease was strongly suggestive of the infiltration of the rectal carcinoma into the epidermal layer, although the ultrastructural and histochemical studies are neccessary to solve the interrelationship between rectal carcinoma and extramammary Paget's disease.