Fibrous pseudotumor of the epididymis: imaging and pathologic correlation

Clinical and ultrasound features of fibrous pseudotumor of tunica vaginalis of the testis: eight cases and literature review

Objective

To investigate the clinical and ultrasound features of fibrous pseudotumor of tunica vaginalis of the testis.

Methods

The clinical and ultrasound features of fibrous pseudotumor of the tunica vaginalis diagnosed by pathology in West China Hospital of Sichuan University from 2006 to 2023 were retrospectively analyzed.

Results

The study included 8 patients diagnosed with fibrous pseudotumor of the tunica vaginalis. The average age was 51.8 ± 17 years(range:25 to 80 years). Painless nodules or masses were present in 87.5% of cases, while 12.5% presented with painless scrotal enlargement. Ultrasound findings were as follows: Lesions were nodular in 7 cases and diffuse in 1 case (left side 50%, right side 50%). 75% involved the tunica vaginalis wall; 25% involved the epididymis with concurrent epididymitis. The tunica vaginalis wall on the affected side was significantly thicker than the contralateral side (4.58 ± 2.19 mm vs. 2.59 ± 0.48 mm, P=0.012). Hydrocele was present in 62.5% of the affected cases, poor sound transmission was noted in 62.5%, and septation was observed in 12.5%. 62.5% of cases exhibited multiple small solid nodules, with a maximum diameter ranging from 8∼19 mm. Nodules were well-circumscribed, regularly shaped and isoechoic or slightly hyperechoic. In 37.5% of cases, adjacent nodules were fused and 37.5% exhibited posterior attenuation. Punctate calcifications were present in 25% of cases. There is usually less blood flow in the lesion.

Conclusion

This study demonstrates that fibrous pseudotumor of the tunica vaginalis is a rare scrotal disease affecting primarily middle-aged and elderly men. It typically presents unilaterally and carries a favorable prognosis following surgical treatment. Ultrasound commonly reveals multiple slightly hyperechoic or isoechoic solid nodules with ipsilateral thickening of the tunica vaginalis wall. In some cases, nodules may involve the epididymis, with associated epididymitis, fusion of adjacent nodules, occasional calcification, and posterior echo attenuation. Most lesions exhibit poor blood flow, and hydrocele is frequently present on the affected side. The distinct clinical and ultrasound features of the disease make non-radiative ultrasound imaging an effective tool for rapid detection, differential diagnosis, and guidance for appropriate clinical treatment.

Paratesticular inflammatory pseudotumour, a rare case

Paratesticular masses are not infrequent, however the diagnosis is challenging. Differentiation from testicular tumours is of utmost importance. One of the rare forms is a fibrous pseudotumours with only about a couple of hundred cases documented worldwide. We present a case of left paratesticular inflammatory pseudotumour.

When to ask for an MRI of the scrotum

Background

Multiparametric MRI (mpMRI) of the scrotum has been established as a useful second‐line diagnostic tool for the investigation of scrotal diseases. Recently, recommendations on clinical indications for scrotal MRI were issued by the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology.

Objective

To update current research on when to ask for an MRI of the scrotum.

Methods

PubMed database was searched for original articles and reviews published during 2010–2021.

Results

Eighty‐three articles fulfilled the search criteria. Scrotal MRI is mainly recommended after inconclusive US findings or inconsistent with the clinical examination and should be asked in the following cases: differentiation between intratesticular and paratesticular lesions (in rare cases of uncertain US findings), characterization of paratesticular and intratesticular lesions (when US findings are indeterminate), discrimination between germ cell and sex cord‐stromal testicular tumors, local staging of testicular malignancies (in patients planned for testis‐sparing surgery), differentiation between seminomas and non‐seminomatous tumors (when immediate chemotherapy is planned and orchiectomy is delayed), assessment of acute scrotum and scrotal trauma (rarely needed, in cases of non‐diagnostic US findings) and detection and localization of undescended testes (in cases of inconlusive US findings). Although preliminary data show promising results in the evaluation of male infertility, no established role for mpMRI still exists.

Conclusion

Multiparametric MRI of the scrotum, by assessing morphologic and functional data represents a valuable problem‐solving tool, helping to improve our understanding on the nature of scrotal pathology and the process of spermatogenesis. The technique may improve patient care and reduce the number of unnecessary surgical procedures.

Paratesticular lesions: Aetiology and appearances on ultrasound

BACKGROUND

Ultrasound (US) is the primary modality for the investigation of scrotal pathology, including both intra- and paratesticular abnormalities.

OBJECTIVE

To describe the abnormalities of the paratesticular space.

MATERIALS/METHODS

The paratesticular space contains the epididymis, spermatic cord and the tunica vaginalis cavity and is affected by a variety of inflammatory or tumoral entities. Differential diagnosis based on US criteria is frequently problematic, as the findings are non-specific.

RESULTS

Some general rules apply: (i) unlike testicular lesions, extra-testicular entities are usually benign in the adult, (ii) the first steps to accurate diagnosis include careful localization of the lesion and assessment of its consistency (solid or cystic) and (iii) magnetic resonance imaging can be useful for further tissue characterization of lesions suspected to contain fat, but surgical biopsy will often provide the definite diagnosis. Contrast-enhanced ultrasound (CEUS) has been applied with limited experience indicating a narrow role, primarily for the differential diagnosis of echogenic cystic entities and the delineation of a necrotic abscess from a solid neoplasm.

DISCUSSION

The various abnormalities are discussed and illustrated.

CONCLUSION

This manuscript summarizes the literature on paratesticular lesions and the value of US in diagnosis.

MR imaging of scrotum

Magnetic resonance (MR) imaging of the scrotum has been used as a valuable supplemental diagnostic modality in evaluating scrotal pathology, mostly recommended in cases of inconclusive sonographic findings. Because of the advantages of the technique, MR imaging of the scrotum may provide valuable information in the detection and characterization of various scrotal diseases. The technique may accurately differentiate intratesticular from extratesticular mass lesions and provide important information in the preoperative characterization of the histologic nature of scrotal masses. An accurate estimation of the local extent of testicular carcinomas in patients for whom testis-sparing surgery is planned is possible.

Fibrous Pseudotumor of the Penis - An Unusual Finding During Repair of Fractured Penis

Fibrous pseudotumors of the testis and penis are a rare phenomenon, forming a spectrum of heterogeneous lesions. To the best of our knowledge, there has been only 1 previous report arising from the penis. We present a case of fibrous pseudotumor of the penis, incidentally found during the surgical repair of a fractured penis. These benign lesions have been described in the literature and are most commonly referred to as pseudotumors. They should be distinguished from potentially malignant lesions, including fibrosarcomas, squamous cell carcinoma, and polypoid urothelial carcinoma. Being aware of this pathology is important to prevent unnecessary radical surgery.

Paratesticular fibrous pseudotumor in young males presenting with histological features of IgG4-related disease: two case reports

Introduction

Paratesticular fibrous pseudotumors represent benign new growths confined to intrascrotal structures. Both pathogenesis and clinical management are little understood due to the rarity of the lesion, with less than 200 cases reported to date. Recently, paratesticular fibrous pseudotumors have been postulated to be immunoglobulin G4-related, pathogenetically. Here we report two cases of patients with paratesticular fibrous pseudotumor to highlight the clinical features of this rare disease and we report the immunohistochemical examinations to support the theory of paratesticular fibrous pseudotumor being an immunoglobulin G4-related disease.

Case presentations

A 28-year-old white man presented with a painless intrascrotal mass. After a clinical examination, a malignant growth was suspected. His ultrasound results revealed a well-demarcated hypoechoic lesion of 1.5cm in diameter at the spermatic cord. Our patient underwent local excision. His follow-up has been uneventful for 12 years. The second case was an 18-year-old white man who presented with a painless scrotal mass suspicious of testicular tumor. A magnetic resonance imaging scan revealed a 3cm mass at the spermatic cord with very low signal density on T2-weighted imaging and a low and inhomogeneous uptake of gadolinium contrast agent on T1-weighted, fat-suppressed imaging. Following local excision, our patient has been well for 18 months.

On histological examination, both of the lesions consisted of collagen-rich hyalinized fibrotic tissue with storiform features. There were lymphofollicular infiltrates and, sporadically, also venulitis. The immunoglobulin G4 staining (in case 2) showed an infiltrate of 10 to 15 positive cells per high-power field on average, corresponding to a proportion of 40% in evaluable hot spots. The two patients with paratesticular fibrous pseudotumor presented within a time span of 15 years. During that time, 400 patients with testicular germ cell tumors had been treated in our institution.

Conclusions

The specific histological features documented in our case lend support to the theory of paratesticular fibrous pseudotumor being an immunoglobulin G4-related sclerosing disorder. Paratesticular fibrous pseudotumors usually occur in young adulthood. Clinically, paratesticular fibrous pseudotumor can mimic testicular malignancy. Ultrasonographic findings are largely unspecific, however, scrotal magnetic resonance imaging may aid in discriminating the lesion from malignant tumors. Local excision, whenever technically feasible, is the preferred treatment of paratesticular fibrous pseudotumor.

Conventional and diffusion-weighted magnetic resonance imaging findings of benign fibromatous paratesticular tumor: a case report

INTRODUCTION

The vast majority of paratesticular masses are benign. Magnetic resonance imaging of the scrotum may provide valuable information in the pre-operative work-up of scrotal masses, by allowing the precise localization of the lesion and helping in characterizing its nature. Diffusion-weighted magnetic resonance imaging is an evolving technique that can be used to improve tissue characterization, when interpreted with the findings of conventional magnetic resonance sequences. We present the case of an adenomatoid tumor of the tunica albuginea, with abundant fibrosis evaluated by magnetic resonance imaging of the scrotum, including both conventional and diffusion-weighted sequences. To the best of our knowledge, there are very few reports in the English literature regarding the magnetic resonance imaging features of this rare benign paratesticular tumor and no report on the diffusion-weighted magnetic resonance findings. We discuss the value of magnetic resonance imaging in the pre-operative diagnosis of benign fibromatous paratesticular tumors and differential diagnosis.

CASE PRESENTATION

A 45-year-old Caucasian man was referred to us with a palpable left scrotal mass. Magnetic resonance imaging of his scrotum revealed the presence of a multilobular left paratesticular mass, mainly detected with very low signal intensity on T2-weighted images and restricted diffusion on apparent diffusion coefficient maps. These findings were suggestive of a fibrous component, and were confirmed on histology following lesion excision.

CONCLUSION

Magnetic resonance imaging of the scrotum, by using both conventional and diffusion-weighted sequences, could have a potential role in the evaluation of scrotal masses.

Ultrasound of the Scrotum

Ultrasound is a vital adjunct to clinical examination in diagnosing scrotal disease, as a number of different processes may present similarly. Potential applications range from the acute emergency to long-term screening as well as cases in which a distinct scrotal abnormality may or may not be palpable. Differentiating acute epididymitis/epididymoorchitis from testicular torsion is possible sonographically, thereby guiding appropriate medical or surgical management. Distinguishing between cystic, solid, or complex scrotal masses is readily performed with this modality. It clearly depicts simple versus complex hydroceles and determines the presence of underlying testicular or epididymal disease. Not only is ultrasound the best imaging modality for longitudinal screening in patients (testicular microlithiasis, cryptorchidism) at risk for testicular tumors, it also provides valuable information in the infertile male by documenting the presence or absence of a varicocele.

From the archives of the AFIP: extratesticular scrotal masses: radiologic-pathologic correlation

The extratesticular scrotal contents consist of the epididymis, spermatic cord, and fascia derived from the embryologic descent of the testis through the abdominal wall. As opposed to intratesticular masses, most extratesticular masses are benign. Cystic masses (including hydroceles, epididymal cysts, and varicoceles) are easily diagnosed with ultrasonography (US) and are benign. Epididymitis is a common extratesticular lesion as well as the most frequent cause of an acute scrotum. It may be either acute or chronic and can be potentially complicated by epididymo-orchitis or scrotal abscess. Findings include epididymal enlargement, skin thickening, hydroceles, and hyperemia. The epididymis can also be affected by sarcoidosis, a noninfectious granulomatous disorder. The most common extratesticular neoplasms are lipomas (most often arising from the spermatic cord) and adenomatoid tumors (most often found in the epididymis). Despite their relative rarity, malignant neoplasms do occur and include rhabdomyosarcoma, liposarcoma, leiomyosarcoma, malignant fibrous histiocytoma, mesothelioma, and lymphoma. These tumors are often large at the time of presentation. The US findings of solid masses are often nonspecific. Magnetic resonance imaging can be very helpful in the evaluation of some of these disorders, allowing for a more specific diagnosis in cases of lipoma, fibrous pseudotumor, and polyorchidism.