American Urological Association - Adenomatoid Tumor
- Benign tumor of mesothelial origin.
- May also occur in other extratesticular serosal sites.
- Most common tumor of testicular adnexa (30%).
- Patient age range 18-79 years (usually seen in 30's or 40's).
- Presents as incidental painless, small and solid intrascrotal mass.
- Circumscribed (<5 cm), unencapsulated, solid, firm gray-white mass (image A).
- Usually arise in the head of epididymis, but may also arise in tunica vaginalis, tunica albuginea and rete testis.
- Gland-like, cyst, tubules, cords, or isolated cells (image B), (image C), & (image D).
- Tumor cells are cuboidal, flat, or ovoid cells with round nuclei and abundant dense cytoplasm.
- May look like vessels and small cell cluster may show signet ring appearance.
- Immunohistochemisty: positive for mesothelial-associated markers (calretinin+, WT1+ and CK5/6+).
- Benign behavior and surgical excision is curative.
- Rare benign vascular tumors: vascular marker Fli-1+; calretinin- and WT1-.
- Metastatic signet ring cell carcinoma: calretinin- and WT1-.