A case of undifferentiated carcinoma of the rectum

症例は69歳女性.下血を主訴に近医受診し,下部消化管内視鏡検査で下部直腸(Rb)にIIc+IIa様の腫瘍を認め,生検では当初扁平上皮癌あるいは低分化腺癌と診断された.治療としては,本人の強い希望で直腸局所切除術を施行.手術標本では組織学的に腺管構造はみられず,免疫組織学的検索で粘液分泌や内分泌顆粒を認めず,未分化癌と診断した.大腸未分化癌の予後は極めて不良とされており早期発見が望まれるが,その初期像については不明な点が多い.稀とされる大腸未分化癌の一例を経験したので,報告する.

This is the case report of a 69-year-old female patient, who presented to a hospital due to melena as the chief complaint. A lower gastrointestinal endoscopy confirmed a 0IIc + IIa tumor found in the patient’s lower rectum (Rb). On a biopsy, this patient was diagnosed with a squamous-cell carcinoma or an undifferentiated adenocarcinoma first. Upon the patient’ s strong request, a local excision of the rectum was performed as the medical treatment for this case. No duct-like structure was observed histologically in the surgical specimen, and the immunohistological detection did not confirm any mucoid secretion or endocrine granules. For these reasons, this patient was diagnosed with an undifferentiated carcinoma. Generally, undifferentiated carcinoma of the colon has a poor prognosis, thus early detection is desirable. However, there exist a number of unclear points in the initial picture of this carcinoma. This is to report our experience of this rare case, which is an example of undifferentiated carcinoma of the colorectal region.

大腸

未分化癌