with tumour extending up to the surgical plane of transection and at the lower end of the spermatic cord. A 76-year-old man presented with right-sided scrotal swelling which had been present for several years.No cysts were noted in the epididymis. Immunostaining for EMA and cytokeratin was positive throughout the Clinical examination showed epididymal cysts which were confirmed on ultrasonography. The epididymal tumour. Special staining for neutral or acidic mucin production was negative but glycogen was present in cysts were excised and a small hydrocele sac plicated, the histology confirming benign simple epididymal cysts. some of the tumour cells. Staining for PSA, carcinoembryonic antigen, AFP and hCG was negative. Metastasis He returned 18 months later with a recurrent right scrotal swelling of a few weeks' duration which was to the testis from a primary elsewhere, germ cell cancer of the testis and tumours arising from the tunica firm, tense, not tender and clinically thought to be recurrent epididymal cysts. Ultrasonography confirmed vaginalis and extending into testis, viz. malignant mesothelioma, were thus ruled out. The histological picture multiple epididymal cysts and showed areas of low echogenicity in the testis suggestive of low-grade infec-satisfied all the criteria formulated by Feek and Hunter [1] to diagnose adenocarcinoma of the rete testis, i.e. tion. As there was no guarantee against a further recurrence the patient opted for an orchidectomy. The the tumour was in the mediastinum rather than testis proper, there was a transition from normal epithelial postoperative recovery was uneventful. The gross appearance of the testis on slicing showed nodules of ill-defined, structures to neoplastic structures in the rete testis, there was no evidence of teratoma, the parietal tunica was pale, firm tumour up to 2 cm in diameter in the mediastinum of the testis, extending into the lower part of the intact and there was no primary tumour at other sites. This last criteria was further fulfilled as CT of the spermatic cord and into the body of the testis. There was a hydrocele sac around the tumour. Microscopic examin-abdomen, pelvis and chest were normal. On the basis of these investigations, adjuvant pelvic radiotherapy was ation showed the tumour to be an adenocarcinoma with a mixture of glandular and papillary patterns projecting given to the patient, encompassing the scrotum, because the tumour extended close to the resection margin. The into the distended cystic spaces (Fig. 1) and the transition from normal to neoplastic epithelium was well marked patient developed multiple metastases in the lungs and Fig. 1. Adenocarcinoma of rete testis with glandular and papillary Fig. 2. Adenocarcinoma of rete testis showing transition from normal to neoplastic epithelium. Haematoxylin and eosin ×100. patterns. Haematoxylin and eosin ×40.922