Table 1 Main differential diagnoses of testicular adenomatoid tumor
From: Epididymal adenomatoid tumor: a case report and literature review
Nature/origin | Gross features | Histology | IHC markers | |
|---|---|---|---|---|
Adenomatoid tumor | Mesothelial epithelium | Well-circumscribed firm, tan nodule | Gland-like spaces lined by vacuolated cells with thread-like bridging strands | WT1, calretinin, D2-40, BAP1, L1CAM, low Ki-67 index |
Malignant mesothelioma | Mesothelial epithelium | Ill-defined tumor of tunica vaginalis invading testicular parenchyma | Trabecular, solid, papillary architecture with cellular atypia and mitoses | CK7, CK5/6, high Ki-67 index, WT1, calretinin |
Spermatocele | Epididymal/rete testis efferent ductules | Cystic, thin-walled lesion, with yellowish fluid content | Fibrous wall lined by flattened, cuboidal or ciliated cells, spermatozoa in the cystic lumen | CK7, PAX8, AR |
Lymphangioma | Lymphatic endothelium | Cystic lesion with clear fluid content | Cystic spaces lined by flattened endothelial cells with amorphous eosinophilic content | D2-40, CD31, CD34, ERG |
Angioma | Vascular endothelium | Cystic lesion with hemorrhagic content | Cystic spaces lined by flattened endothelial cells containing red blood cells | CD31, CD34, ERG, factor VIII-related antigen |
Yolk sac tumor | Germ cell tumor | Intraparenchymal testicular tumor | Microcystic reticular pattern, Schiller–Duval bodies | SALL4, AFP, glypican 3, CDX2 |