CASE 7596 Published on 17.09.2009

Magnetic resonance imaging of penile metastases in a patient with bladder cancer.

Section

Uroradiology & genital male imaging

Case Type

Clinical Cases

Authors

Maschio V, Maschio C, Zizzi N, Manfredi M, Caputo L, Stella A.

Patient

84 years, male

Clinical History
A 84 year old man with muscle invasive transitional cell carcinoma of the bladder and two months history of painful priapism was admitted to our department.
Imaging Findings
The patient presented with haematuria. Cystoscopy revealed a solid lesion on the base of the bladder and histology showed high grade transitional cell carcinoma. The patient refused surgical treatment and few months later he was admitted to our unit for painful priapism.
MRI was performed with equipment 1,5 T. The patient was positioned supine and did not need to use a towel beneath the scrotum for the stability. A surface coil is placed on the penis to obtain optimal-quality, high-resolution images.
The penile metastases in our patient were ill-defined areas of inhomogeneous low to intermediate signal intensity on both T2-weighted and STIR images. However, they were readily visible against the high background signal intensity of the cavernosal bodies on these sequences. On T1-weighted images the masses had isointense with the surrounding corpus cavernosum. Its presence could however be inferred if there was distortion of the corporal contour. After administration of gadolinium the metastases secondary tumours enhance on images T1W with fat saturation, although to a lesser extent than the corpora cavernosa. The patient had bilateral inguinal lymphadenopathy.
Discussion
Metastases to the penis are rare and may manifest with malignant priapism. There are even fewer references to priapism of metastatic origin. Of some 300 cases of penile metastases in the literature 35% were secondary to TCC of the bladder. In approximately 70% of cases, penile metastases arise from other primary malignancies of portions of the genitourinary tract such as the prostate or urinary bladder (1,2).
In most cases the corpora cavernosa are involved, with or without concomitant involvement of the corpus spongiosum. Occasionally, only the glans is involved. The size of the nodules varies from 0.4-5cm. Metastases to the penis most commonly present with difficulty in voiding. This could progress to acute retention of urine due to compression of the urethra by the tumour. The second most common symptom is pain. Priapism is also a common complaint. This is due to either tumour infiltrating the corpus cavernosum, venous stasis resulting from compression of venous outflow, or reflex irritation of the nerves by tumour infiltration. Although penile masses are readily recognized on clinical examination, imaging is often required to assess fully the extent of involvement by tumour and to guide therapy, particularly if surgical amputation is considered. Cavernosography has been used to confirm the diagnosis and assess the extent of disease. Metastases are seen as filling defects or structural deformities affecting the corpora cavernosa, corpus spongiosum or glans penis. Ultrasound has been used in evaluating various penile conditions, including trauma, inflammatory conditions, Peyronie disease and erectile dysfunction. Its use in penile metastasis has also been recorded. CT scan has also been used to demonstrate penile metastases. MRI is non-invasive, has superior soft tissue contrast and multiplanar capabilities. The metastases are discrete masses, located mostly within the corpora cavernosa. These lesions show heterogeneous signal intensity with ill-defined areas of low signal intensity on T2-weighted images. MRI may therefore help clinicians anticipate the onset of urinary symptoms. In summary, MRI is suitable and reliable in imaging penile metastases (3). It allows direct tumour visualization, and these are often seen as discrete masses.
Differential Diagnosis List
Penile metastases of bladder cancer.
Final Diagnosis
Penile metastases of bladder cancer.
Case information
URL: https://www.eurorad.org/case/7596
DOI: 10.1594/EURORAD/CASE.7596
ISSN: 1563-4086