Primary adenocarcinoma of the right seminal vesicle

Clinical History

A 70-old-year male patient came to our hospital with constitutional symptoms (weight loss, asthenia and anorexia) and obstructive uropathy.

Imaging Findings

A simple abdominal CT was performed. In this study, a large, well-defined mass on the pelvis was discovered. The mass appeared with predominately low density (Fig. 1).

A pelvic magnetic resonance imaging (MRI) was performed to further characterise this mass. It showed a 9 cm retrovesical solid mass. On T2-weighted images, the mass showed a heterogeneous hyper-intense signal (Fig. 2). The mass contacted the posterior wall of the urinary bladder and the anterior wall of the rectum and the prostate (Fig. 3). In the coronal view (Fig. 4) the mass showed prostatic invasion.

Discussion

Primary adenocarcinoma of the seminal vesicles is an extremely uncommon neoplasm (with only around 52 reported cases in the literature) that requires for diagnosis the exclusion of a primary prostatic neoplasm [1]. Malignant lesions of the seminal vesicles are most often the result of secondary spread from others tumours, most commonly prostate, rectum and bladder cancer [2].
It commonly occurs in older patients. Seminal vesicle carcinoma typically presents as advanced, symptomatic disease. Although the most common symptoms are obstructive uropathy, haematuria, haematospermia and general pelvic pain, these symptoms are quite nonspecific [3]. The tumour size at the time of the diagnosis is usually large, and generally involves other organs.
Imaging of the pelvis has a crucial role in assessment of seminal vesicles to confirm the presence of lesion and also to evaluate the invasion. Magnetic resonance imaging has the advantage of increased soft tissue resolution allowing identification not only of the seminal vesicles but also adjacent structures such as vas deferens, rectum, urethra, bladder, and prostate [2].
In this case a transrectal biopsy was performed to make a definitive diagnosis. The histology examination showed a seminal vesicle adenocarcinoma. The cytokeratin profile may also aid diagnosis, with seminal vesicle carcinoma typically showing strongly positive staining for cytokeratin 7 (CK7) and negative CK20.
The treatment is the total excision of the tumour with free surgical margins. Radiotherapy has been used as neoadjuvant therapy with limited success, mostly in combination with surgical or androgen deprivation therapy.
The lack of early or specific clinical presentation leading to late identification of these tumours contributes to their poor prognosis [2].

Differential Diagnosis List

Final Diagnosis

Seminal vesicle adenocarcinoma

URL:	https://www.eurorad.org/case/10047
DOI:	10.1594/EURORAD/CASE.10047
ISSN:	1563-4086