GIANT LEIOMYOSARCOMA OF THE RECTUM - REPORT OF A CASE AND REVIEW OF 122 SURGICALLY TREATED CASES OF RECTAL LEIOMYOSARCOMAS IN JAPAN

Rectal leiomyosarcoma (RLS) is rare and represents a serious challenge to both pathologists and surgeons as far as the difficulty in differe ntiation from leiomyoma and selection of the optimal mode of surgical or other therapies are concerned. In this report a case of RLS in whic h a preoperative biopsy diagnosis of leiomyoma was revised to leiomyos arcoma based on the information added by various imaging modalities is presented. This appears to be the first English report of RLS in whic h MRI-CT and angiography are used concomitantly. Such an approach is c rucial in order to define the malignant characteristics of the tumour, and to detect the organ of origin, extent of invasion and distant spr ead. We also review the Japanese literature and discuss the natural be haviour, diagnostic and therapeutic aspects of this uncommon tumour in the light of 122 cases of RLS reported in Japan. Two striking points deserve emphasis: 1) the high rate of diagnostic inaccuracy (34%) and false leiomyoma diagnosis (26%) in preoperative biopsies; 2) the unexp ectedly high rate of local lymphatic metastasis (16%) during primary s urgery. We think that an aggressive diagnostic and therapeutic approac h to RLS offers a chance of better survival and seems justifiable.