TUMOLJRS of the spermatic cord are rare. In the literature available to us we have found reports of only seven leiomyomata of the cord (Portalier, 1908;Lapeyre and O'Daly, 1937; McCook, 1942; Strong, 1942;Zuckner and Aronberg, 1951;Bormel and Young, 1961). In all these cases there was some doubt about the tissue of origin of the tumour, and the following possibilities have been suggested: the smooth muscle of the cremaster (Portalier, 1908), that of the blood vessels in the cord (Bormel and Young, 1961), and that of the vas deferens (Army Registry of Pathology, 1946). The case here reported presents, as we think, convincing evidence of origin from the vas deferens itself. Case History.-A 39-year-old man complained of a lump, present for five years, in relation to his left testis. When first noticed it had been about the size of a small marble. About 15 months before he came to hospital it had become a little painful, and he had noticed that it was a double lump. It did not change in size thereafter, but it did become more painful, and this led him to seek treatment. Examination showed that he had an hour-glassshaped swelling about 4.0 cm. long above his left testis. The lump was neither tender nor fluctuant.At operation the left side of the scrotum was opened and the testis exposed. A solid bi-spherical encapsulated tumour was found, loosely attached to the upper pole of the testis but quite clear of the epididymis. The vas deferens appeared to be adherent to the tumour, but when an attempt was made to dissect the vas off the tumour no plane of cleavage could be found. The vas was therefore divided above and below the tumour and removed in continuity with it. The patient made a straightforward recovery, but defaulted from follow-up after one month.Pathology Report.-The specimen as received was a firm object roughly the shape of an hour glass measuring 4.5 x 2.5 x 2.3 cm. The " waist " was apparently partly encircled by the vas deferens, the vas being about 5.0 cm. long (Fig. 1). Close examination showed that the vas appeared to run through the substance of the mass, not diametrically but quite close to the surface. The cut surface of the tumour closely resembled that of a uterine fibromyoma.Sections were stained by hiematoxylin and eosin, hrematoxylin and Van Gieson, and phosphotungstic acid hrematoxylin (Figs. 2 and 3). Microscopy left no doubt that the lesion was a benign ieiomyofibroma, and also confirmed that the vas deferens did indeed pass through the substance of the neoplasm. In fact, within the tumour the structures of the wall of the vas could no longer be discerned, but on its " line " there were collections of spermatozoa and macrophages, some of which had more than one nucleus.It was concluded that the tumour was truly a leiomyoma which had arisen in the muscle of the vas deferens.Comment.-Thompson (1936) reviewed the literature on tumours of the spermatic cord. He found 216 recorded cases, and added 24 more seen at the Mayo Clinic. Of the 240 cases thus collected about one-third were lipomata, the ...