直腸平滑筋肉腫の1治験例

A Case Report of Leiomyosarcoma of the Rectum

　直腸平滑筋肉腫は，内外共に稀なものとされており，最近急速に報告が増えているが，それでも本邦報告例は26例にすぎない．われわれも下血を主訴とする1例を経験したので報告する．

　Leiomyosarcoma of the rectum is very rare in the literature. We found only one case among 166 cases of rectal cancer and 1335 cases of all malignant tumors of alimentary tract, which corresponded to 0.6% and 0.07% respectively in our series of past 10 years. There have been many controversies on its terminology, clinical diagnosis, degree of malignancy and its treatment.

　A 65-year-old female suddenly collapsed after massive anal bleeding on 6 Oct., 1972. She was transfered to National Tochigi Hospital on 24 Oct. from a local hospital where she had received 3,400 ml of blood transf usion.

　A spheric mass under fist size, locating at right posterior wall of anorectal junction, was palpated on digital examination. The same findings were revealed by barium-enema. Deviation and stretching of superior hemorrhoidal artery and only a few tumor-vessels were found by selective angiography.

　Under the diagnosis of submucosal tumor of the rectum, combined abdominoperineal resection was performed on 6 Nov. No metastasis to the liver was found macroscopically. The submucosal tumor was measured approximately 8×6.5×6 cm, with erosion on its top, and its cut surface was white and solid with few necrotic spaces.

　Histopathologically the tumor was composed mainly of fibrous bundle of spindle cells, with increase and inequality in size of nuclei, counting 13 micotic figures per 10 high-power fields, and no metastasis to the regional lymphnodes was found, Dilated vessels and inflammatory cell infiltration were seen beneath the mucosal erosion, which was thought to be the point of massive bleeding.

　Although prognosis of leiomyosarcoma is variable in the literature, she is very well 27 months after operation.