Related Experiment Video
Updated: Feb 1, 2026
Teratoma Generation in the Testis Capsule
Published on: November 7, 2011
[Myeloid Sarcoma of the Testis]
Kenta Yoshida1, Koichi Uemura1, Masahiro Inoue1
1The Department of Urology, Yokohama City Minato Red Cross Hospital.
Insights
A rare case of myeloid sarcoma, an extramedullary tumor of immature myeloid cells, was diagnosed in a 68-year-old man presenting with testicular swelling. This condition, though uncommon in the testis, carries a poor prognosis and requires consideration in differential diagnoses.
Area of Science:
- Oncology
- Hematology
Background:
- Myeloid sarcoma is an extramedullary tumor composed of immature myeloid cells.
- Primary testicular involvement by myeloid sarcoma is a rare clinical presentation.
Observation:
- A 68-year-old man presented with a 40 mm testicular mass, diagnosed as myeloid sarcoma via orchiectomy and immunohistochemistry (myeloperoxidase positive, T-cell/B-cell negative).
- No evidence of leukemia was found in peripheral blood or bone marrow at diagnosis.
Findings:
- The patient developed para-aortic lymph node enlargement 11 months post-orchiectomy, indicating recurrence.
- Chemotherapy was initiated for the recurrent myeloid sarcoma.
Implications:
- Testicular myeloid sarcoma, despite its rarity, is a critical differential diagnosis for testicular masses.
- Early recognition and management are crucial due to the typically poor prognosis associated with this condition.
Abstract:
A 68-year-old man with swelling of his left testis was referred to our hospital. There was no history of hematologic disease. The diameter of the testicular mass was 40 mm. We performed a left orchiectomy. Histopathologic examination revealed diffuse infiltration of immature neoplastic cells with a high nuclearcytoplasmic ratio. Immunohistochemical analysis revealed that cells were positive for myeloperoxidase, while T-cell and B-cell markers were negative. There was no evidence of leukemia cells in peripheral blood or in bone marrow. The tumor was diagnosed as a testicular isolated myeloid sarcoma. Eleven months after the orchiectomy, enlargement of the para-aortic lymph node occurred. There was no evidence of leukemia cells in the peripheral blood or bone marrow. The patient is undergoing chemotherapy for recurrence of myeloid sarcoma. Myeloid sarcoma is an extramedullary tumor composed of immature myeloid cells. Myeloid sarcoma primarily involving the testis is rare. However, it is important to consider it as a differential diagnosis because it has a poor prognosis.
Related Concept Videos
01:03Rous Sarcoma Virus (RSV) and Cancer
RSV is a retrovirus that contains two copies of a plus-strand RNA genome. Its genome consists of four main open...
01:15Differentiation of Common Myeloid Progenitor Cells