What are Adenomatoid Tumours?
Adenomatoid tumours are relatively uncommon benign (non-cancerous) growths of mesothelial origin, frequently located within the genital tract organs. These tumours are the second most common lesions of the epididymis, accounting for about 30% of all paratesticular (adjacent to the testicle) lesions. They typically occur in men aged 20 to 50 years and are solid, usually painless, and slow-growing.
Where are Adenomatoid Tumours Found?
Adenomatoid tumours can be found in various locations within the genital tract for both males and females:
- Male Genital Tract: Epididymis, spermatic cord, prostate, and ejaculatory duct.
- Female Genital Tract: Uterus, fallopian tubes, and ovarian hilus.
What Are The Symptoms and Presentation of Adenomatoid Tumours?
Adenomatoid tumours often present as an incidental finding or a slow-growing scrotal mass, most commonly in patients between 30 and 50 years of age. The enlargement is typically painless, with the scrotal skin and surrounding tissues remaining normal. In rare cases, patients may experience testicular pain. Most adenomatoid tumours are less than 2 cm in diameter and are uniformly benign.
How Are Adenomatoid Tumours Diagnosed?
Ultrasound (US)
Ultrasound is the primary imaging technique used to diagnose adenomatoid tumours. These tumours typically appear as well-defined, homogeneous, round nodules with variable echogenicity ranging from hypoechoic (darker) to hyperechoic (brighter).
Magnetic Resonance Imaging (MRI)
On MRI, adenomatoid tumours are slightly hypointense (darker) compared to the testicular tissue on T2-weighted images and show similar enhancement to the testis on post-contrast images.
Pathological Examination
Microscopically, adenomatoid tumours exhibit various histological patterns, including adenoid or tubular glandular, angiomatoid, solid, cystic, or transitional. These patterns can pose diagnostic challenges, especially in differentiating adenomatoid tumours from other paratesticular tumours.
Differential Diagnosis
Distinguishing adenomatoid tumours from malignant intratesticular tumours can be challenging due to similar imaging and clinical features. Paratesticular tumours are more frequently benign and can often be cured by local excision, unlike testicular neoplasms, which are 95% malignant.
Common Paratesticular Tumours and Their Features:
- Fibrous Pseudotumor: Dense fibrous tissue with fibroblasts and mixed inflammatory cells.
- Cystadenoma: Epithelial-like tumour cells with cystic dilatations.
- Leiomyomas: Bundles of smooth muscle cells.
- Serous Borderline Tumor: Cystic with intracystic, blunt papillae lined by stratified epithelial cells.
- Mesothelioma: Epithelioid cells arising from the tunica vaginalis with various architectural patterns.
Treatment and Prognosis
Since adenomatoid tumours are benign, they generally do not require treatment unless they cause discomfort or other complications. In such cases, surgical removal (local excision) may be considered. The prognosis for individuals with adenomatoid tumours is excellent, as these growths do not spread or become cancerous.
Words of Wisdom from a Consultant Urologist
When faced with a diagnosis of an adenomatoid tumour, it's essential to understand that this condition is benign and typically does not pose a serious health threat. An asymptomatic mass in the scrotum can be caused by both benign lesions and malignancies. Ultrasound is the first-line imaging technique used to assess scrotal masses and can often be the only modality required. However, distinguishing adenomatoid tumours from malignant intratesticular tumours remains challenging, sometimes leading to unnecessary extensive surgical excision of the entire testis.
