[Importance of morphological studies for precise determination of the limits of local spread of rectal cancer].

115 samples of the rectum were investigated after radical operation for its cancer. In 61 samples its intramural distribution was studied by means of transverse section of the rectum distally to tumor as well as the involvement of regional lymph nodes, cellular tissue and sphincter muscles. The preferential direction of tumor invasion in different stages of cancer growth is a "perpendicular" tumor growth. In 6 samples the spread of distal intramural growth exceeds 2 cm and in 1 sample -- 6cm. No sphincter involvement was noted. Regional metastases were found in 37 per cent of observations. Retrograde metastases were detected in 3 samples. In 7 of 15 samples with total proliferation of the rectal wall tumor elements were detected in peripheral cellular tissue "perpendicularly" above the tumor. The problem of the adequate extent of the operation should be solved taking into account the tumor site, histological structure, limits of intramural and extramural growth and tumor size.