Primary leiomyosarcoma in testis is an uncommon tumor with few cases reported. It generally develops after radiotherapy or long-term taking anabolic steroid medication. We report a 53-year-old male patient with primary testis leiomyosarcoma who presented with painless testicular enlargement without any known predisposing factors. Ultrasound revealed a large heterogeneous left testicular solid lesion. Alpha-fetoprotein (AFP) and beta-human chorionic gonadotrophin (beta-HCG) levels in serum were normal. Left radical orchidectomy following with histology assessment established a diagnosis of primary leiomyosarcoma of testis. No data of cancer metastasis was established. The patient didn't receive any adjuvant therapy. There wasn't any evidence of recurrence after 1 year follow-up. Leiomyosarcoma must be one of the differential diagnoses of seronegative tumors in testis. The motivation for this paper is the extreme infrequency of the situation and the differential diagnosis by all expansive inguinoscrotal tumors.
Keywords: leiomyosarcoma; orchiectomy; testis.