A 42-year-old man consulted for a right testicular mass and pain, of 2 months' evolution, which progressively increased. He denied any other pathological history or other symptoms. Testicular ultrasound showed a diffuse increase in the size of the right testicle, measuring 6.2x5.8x4.2 cm, with diffuse alteration of its echogenicity. Therefore, he underwent orchidectomy and was found to have an enlarged, rubbery, whitish testicle. The histopathological study showed diffuse infiltration of the testicular parenchyma by a malignant haematolymphoid neoplasm composed of small, irregular cells with scant cytoplasm, which showed angiotropism, with associated areas of necrosis. The tumour cells were positive for ACL and CD3 with Ki67 of 90% and negative for TdT, CD30, ALK, bcl2, bcl6 and CD10. Based on the above, a diagnosis of unspecified peripheral non-Hodgkin T lymphoma was made.

