Testis & paratestis
Other tumors
Myeloid sarcoma
Author: Jennifer Gordetsky, M.D.
Last author update: 1 August 2013
Last staff update: 6 January 2021
Copyright: 2003-2023, PathologyOutlines.com, Inc.
PubMed Search: Granulocytic sarcoma[title] or myeloid sarcoma[title] testis
Table of Contents
Definition / general | Terminology | Epidemiology | Pathophysiology | Clinical features | Diagnosis | Laboratory | Radiology description | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Differential diagnosis | Additional referencesCite this page: Gordetsky J. Myeloid sarcoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisgranulocyticsarcoma.html. Accessed May 30th, 2023.
Definition / general
- Neoplasm composed of immature and mature granulocytes or monocytes that involves an extramedullary anatomic site
- Includes leukemic involvement of testis
- Common with ALL: 8% clinically, 20% microscopically; also AML
- Bilateral involvement common
- Testis may be first site of relapse
Terminology
- Also called chloroma, myeloid sarcoma, monocytic sarcoma, extramedullary myeloid cell tumor, myelosarcoma, myeloblastoma
Epidemiology
- Rare; case reports of ages 24 - 68 years
Pathophysiology
- Usually history of myeloid neoplasm, most often acute myeloid leukemia, less often a myelodysplastic or myeloproliferative disease
- Testicular involvement can be initial manifestation of AML that subsequently involves blood and bone marrow
- Very rarely, testis is only site
- Relatively more common with leukemias with prominent monocytic differentiation (acute myelomonocytic or acute monocytic leukemia, chronic myelomonocytic leukemia, Am J Clin Pathol 2005;124:445)
Clinical features
- Testicular mass, testicular pain, constitutional symptoms (fever, general weakness, night sweats, weight loss)
Diagnosis
- Based on histology and confirmed by immunohistochemical stains or flow cytometry
- Clinical history can be very helpful
Laboratory
- AFP and beta HCG within normal limits
Radiology description
- Testicular ultrasound is imaging modality of choice for a scrotal mass (Semin Ultrasound CT MR 2013;34:257, Gordetsky: Gordo's Guide to GU Pathology: A Resource for Urology and Pathology Residents, 2013)
Case reports
- 33 year old man with painless testicular swelling (Urology 2004;64:807)
- 35 year old man with history of CML and enlarged tender testis (Kaohsiung J Med Sci 2004;20:506)
- 37 year old man with sharp, severe, localized testicular pain (Urology 2004;63:584)
- 4 patients (Am J Clin Pathol 2005;124:445)
Treatment
- Chemotherapy or radiation therapy, although bone marrow relapse is common
Gross description
- Cream colored to yellowish tan, rubbery / firm testicular tumor with extensive paratesticular spread
Gross images
Images hosted on other servers:
Cream colored tumor
Microscopic (histologic) description
- Normal testis architecture is effaced by primitive cells with scant cytoplasm; or cells with eosinophilic, occasionally granular cytoplasm
- Prominent myelocytes with moderately abundant cytoplasm and round eccentric nuclei, resembling plasma cells
Microscopic (histologic) images
Images hosted on other servers:
Myeloperoxidase
Cytology description
- Cellular, discohesive cells with moderate cytoplasm, large oval to indented nuclei, distinct nuclear membranes
- Also cells with scant cytoplasm, no eosinophilic granules, round / oval nuclei with prominent nucleoli (Ann Diagn Pathol 2000;4:17, Cancer 2000;90:364)
- Variable numbers of eosinophilic myeloblasts, myelocytes and other maturing cells with eosinophilic granules - in some cases, myeloid differentiation is absent
- Lymphoglandular bodies may be present in background
Positive stains
Negative stains
- CD20, CD3, cytokeratin, EMA
Differential diagnosis
- Large cell lymphoma: need clinical history
- Orchitis: heterogeneous cell population
- Plasmacytoma
- Seminoma: has intratubular germ cell neoplasia, PLAP+
Additional references
