CASE 10011 Published on 05.04.2012

Complex cystic spermatocytic seminoma with synchronous contralateral classical seminoma: MRI findings

Section

Uroradiology & genital male imaging

Case Type

Clinical Cases

Authors

Soler R, Méndez C, Rodríguez E, Delgado C1, Fernández N, Álvarez L, Romeu D

Departments of Radiology and Pathology1.
Complejo Hospitalario Universitario A Coruña.
A Coruña. Spain
Patient

59 years, male

Categories
Area of Interest Genital / Reproductive system male ; Imaging Technique MR, PACS
Clinical History
A middle-aged man presented with a 10-month history of a painless left scrotal swelling. He had no history of epididymitis, torsion, trauma, or cryptorchidism. Physical examination revealed an enlarged swelling in the left testis with the right testis being normal. Laboratory studies, including α-fetoprotein, β-human chorionic gonadotropin, and serum testosterone levels were normal.
Imaging Findings
Testicular MRI showed a small well-defined nodule in the right testis, isointense to parenchyma on T1-weighted (Fig. 1) and hypointense on T2-weighted images (Fig. 1b). The left testis was replaced by a large cystic cavity, hypointense on T1-weighted images and hyperintense with a peripheral hypointense rim on T2-weighted images (Fig. 1, 2) and a complex nodule of intermediate signal intensity on T1-weighted images and heterogeneous high signal with hypointense septa on T2-weighted images (Fig. 2). After contrast-enhancement, the right testis showed heterogeneous enhancement and the left testicular mass presented peripheral and heterogeneous enhancement (Fig. 3).
A bilateral radical orchiectomy was performed. Pathological examination demonstrated a classical seminoma in the right testis (Fig. 4) and a spermatocytic seminoma in the left testis (Fig. 5). The large cystic cavity was a cystic dilatation of the rete testis secondary to intratubular tumoral growth.
Discussion
Bilateral germ-cell testicular tumours are very rare, and even more when they are synchronic. Synchronous bilateral testicular tumours usually present with a classical seminoma and a nonseminomatous tumour in the contralateral testis [1, 2].
Seminoma is a malignant germ-cell tumour that affects young men from 30 to 55 years. Patients typically show a self-detected testicular mass that is sometimes associated with an ill-defined aching sensation in the lower abdomen or scrotum. In 10–25% of patients, seminomas are associated with an elevated β-HCG level [3].
Histologically, they are usually solid, lobulated masses that may contain sharply circumscribed areas of necrosis. Microscopically, tumour cells are uniform with abundant clear cytoplasm characteristically arranged in nests outlined by fibrous bands. As in our case, these tumours appear as a homogeneous hypointense lesions on T2-weighted images. Fibrovascular septa may be seen as hypointense band-like structures on T2-weighted images. These imaging characteristics reflect their uniform cellular nature [3, 4].
Spermatocytic seminoma is a very rare germ-cell tumour that occurs in older adults (60 years). They usually manifest as unilateral, painless swelling and have a negative tumour marker profile. Bilateral involvement occurs in 10% of cases and is usually asynchronous [5, 6]. Unlike classical seminoma, spermatocytic seminoma have never been reported as primary at extragonadal sites [5].
Macroscopically, they appear as a multinodular fleshy white tumour with cystic, mucoid, and haemorrhagic areas. Microscopically, the most distinctive feature is its cellular polymorphism, represented by three cell types (small, intermediate, and large) typically arranged in sheets punctuated by occasional cystic spaces filled with eosinophilic fluid [7]. The biological behaviour is generally indolent, but anaplastic variant or sarcomatoid changes have been reported in about 5% of cases [5].
To our knowledge, this is the first description of the MRI findings of spermatocytic seminoma. In our case, testicular mass showed a large, sharply demarcated cystic cavity and a well-circumscribed complex nodule with multiple cystic areas and thick septa. At MRI, the complex nodule showed heterogeneous intermediate signal intensity on T1-weighted images, heterogeneous hyperintense signal with hypointense septa and hypointense peripheral capsule on T2-weighted images and showed peripheral and heterogeneous gadolinium enhancement. Histologically, the complex cystic tumour showed testicular intratubular excretory growth with subsequent large cystic dilatation of the rete testis. Occlusion of the ductal system with secondary cystic rete testis dilatation has been previously reported in other tumours [8].
Differential Diagnosis List
Cystic spermatocytic seminoma with synchronous contralateral classical seminoma
Lymphoma
Bilateral germ-cell tumours
Leydig-cell tumours
Final Diagnosis
Cystic spermatocytic seminoma with synchronous contralateral classical seminoma
Case information
URL: https://www.eurorad.org/case/10011
DOI: 10.1594/EURORAD/CASE.10011
ISSN: 1563-4086

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