Benign paratesticular inflammatory pseudotumor: A rare case report

Abstract

Paratesticular inflammatory pseudotumor is a rare entity that poses significant challenges in diagnosis and treatment due to its clinical and radiological appearance, which can mimic malignancy. We report the case of a 52-year-old male who presented with a painful mass in the left testicle. A few weeks later, the patient developed backache and leg stiffness. A left radical orchiectomy was performed, and postoperative biopsy results were obtained. Histopathological examination is crucial for definitive diagnosis, and early recognition along with appropriate surgical intervention is essential for effectively managing these benign tumors. This case contributes to the expanding literature on the unique disease entity.

Introduction

Inflammatory pseudotumors are benign neoplasms that can arise from various organs throughout the body [1]. The term “inflammatory pseudotumor” was introduced by Umiker and Iverson to describe these lesions, which can clinically resemble malignant tumors [2]. The etiology of inflammatory pseudotumors remains unclear, and no definitive causal agent is often identified [3]. While these tumors most frequently affect the pulmonary system, there is evidence of their involvement in the genitourinary system, with the bladder being the most commonly affected organ [4].

Paratesticular inflammatory pseudotumors are relatively rare, with limited reports in the literature [5]. These lesions account for approximately 6% of paratesticular lesions, with peak incidence occurring between the ages of 20 and 40 years [6].

This paper presents the case of a 52-year-old male who exhibited nonspecific symptoms, including left testicular pain, swelling, backache, and radiological findings suggestive of malignancy. Consequently, the patient underwent a left radical orchiectomy. Postoperative biopsy results confirmed the diagnosis of a benign paratesticular inflammatory pseudotumor.

Case presentation

A 52-year-old male patient with a medical history of hypertension and poorly controlled type 2 diabetes mellitus presented to the emergency room (ER) with a 2-day history of dizziness, intermittent fever, and chest pain accompanied by vomiting. He reported noticing a painful mass in his left hemiscrotum. Three months prior, the patient had presented to a healthcare center with severe left testicular pain and was initially diagnosed with epididymitis, with no evidence of testicular torsion found on ultrasound. He was treated for epididymo-orchitis with analgesics and antibiotics.

Aside from fever, the patient was hemodynamically stable. Chest examination was unremarkable; however, genital examination revealed a painful mass in the left hemiscrotum. Ultrasound of the scrotum showed an enlarged heterogeneous left spermatic cord with hypervascularity (Fig. 1, Fig. 2, Fig. 3). Laboratory results were notable for elevated lactate dehydrogenase (LDH). The patient improved with pain management and was discharged with an urgent referral to urology for suspected cancer.

Fig. 1.

Ultrasound scrotal shows enlarged heterogeneous left spermatic cord with hypervascularity and patch areas of calcifications. Left Epididymal head cannot be seen separately (A and B).

Fig. 2.

Ultrasound scrotal shows both testes were normal in size, echogenicity and vascularity. No definite focal lesions detected (A and B).

Fig. 3.

Ultrasound scrotal shows significant progression of the left spermatic cord enlargement forming mass like lesion with peripheral vascularity in Color Doppler (A-C).

During the urology visit, an MRI of the scrotum was requested to rule out any neoplasm in the left spermatic cord. The MRI results showed a left extra-testicular ill-defined serpiginous mass with low signal on T2-weighted images (T2WI) and iso-signal on T1-weighted images (T1WI) at the opening of the inguinal canal (Fig. 4). Differential diagnoses included filariasis, paratesticular granuloma, paratesticular lipoleiomyoma, and leiomyosarcoma.

Fig. 4.

(A and B) Axial T2WI and T1WI shows left extra-testicular ill-defined serpiginous heterogeneous mainly low signal in T2 WI and iso-signal in T1WI at the opening of inguinal canal along the spermatic cord inseparable from Epididymal head. (C and D): Axial In and Out-phases, the lesion showing areas of fat contents. (E and F): DWI and ADC map the lesion showing areas of areas of diffusion restrictions.

A few weeks later, the patient developed backache and leg stiffness. A positron emission tomography (PET) scan showed increased uptake in parts of the left scrotal mass with indeterminate background (Fig. 5), suggestive of malignant pathology. Eventually, the patient underwent left radical orchiectomy, and a surgical specimen was sent for histopathological analysis. The results showed a paratesticular tumor at the base of the spermatic cord consisting of spindle-shaped myofibroblastic-like cell proliferation, associated with chronic inflammatory cell infiltrate composed of lymphocytes, multinucleated giant cells, and a few plasma cells. Importantly, no increased mitotic figures, atypical cells, or necrosis were identified, confirming the diagnosis of benign paratesticular inflammatory pseudotumor. The patient's postoperative course was uneventful.

Fig. 5.

(A-E Coronal T1WI dynamic postcontrast sequences and G and H: Coronal subtraction postcontrast sequences): shows heterogeneous progressive enhancement with edematous scrotal wall. Left testicles is separated from the lesion displaced inferiorly with normal and signal intensities and enhancement.

Discussion

Paratesticular tumors account for about 5% of all intrascrotal neoplasms [7] and are typically benign [8]. Approximately 75% of these tumors originate from the spermatic cord [7]. They can occur in all age groups, including the elderly [5].

While the precise cause is not well understood, it is believed that these tumors may arise due to chronic irritation from factors such as trauma, infection, or autoimmune conditions [9]. Genetic abnormalities in genes like ALK and ROS1 have also been linked to their development [10]. These tumors are thought to result from the proliferation of myofibroblasts and inflammatory cells [11].

Clinically, these lesions can present as a painless single nodule, multiple discrete nodules, or a diffuse multinodular hemiscrotal mass. Their hard consistency often complicates differentiation from malignant lesions [12]. Recent speculation suggests a possible correlation with IgG4-related diseases, as some tumors contain IgG4-expressing plasma cells [12]. Garber et al. reported a case of an IgG4-related paratesticular inflammatory pseudotumor in a patient with a painless right testicular mass [13]. In contrast, our patient presented with a painful left testicular mass, but investigations showed no increase in IgG levels.

Diagnosing paratesticular tumors is challenging due to their rarity and lack of specific clinical features. Their presentation and imaging characteristics are often nonspecific and can mimic other neoplasms or inflammatory conditions [11]. Radiologically, ultrasonography is typically the first modality used for examination. Scrotal ultrasonography helps determine if a lesion is solid or cystic and whether it is intratesticular or extratesticular [14]. Depending on the level of calcification, hyalinized collagen, and granulation tissue, these lesions may appear hyperechoic or hypoechoic [14]. Color Doppler ultrasound may show mild vascularity [15]. Due to these nonspecific features, diagnosing paratesticular inflammatory pseudotumors based solely on ultrasound can be challenging, as they may be mistaken for a testicular tumor or chronic testicular infarction during preoperative assessment. When ultrasound results are inconclusive, MRI can provide additional information, improving tissue characterization and tumor delineation [14]. These lesions typically appear as low-intensity on T1- and T2-weighted MRI images due to the presence of fibrosis [14].

Differentiating malignant tumors from inflammatory pseudotumors is crucial, as malignant tumors typically exhibit imaging characteristics such as irregular contours, possible necrotic areas, poorly defined margins, and postcontrast enhancement. Furthermore, lymphadenopathy is often present. These characteristics are significant diagnostic indicators for evaluating malignancy and necessitate further investigation to clarify the nature of the mass and its potential impact on patient management [16]. In our patient, the ultrasound showed an enlarged heterogeneous spermatic cord with hypervascularity, and the follow-up MRI revealed a left extratesticular ill-defined mass in the inguinal canal along the spermatic cord, inseparable from the epididymal head.

A definitive diagnosis can only be made through histopathological assessment [12]. Immunohistochemical (IHC) staining is valuable in confirming the diagnosis and identifying specific molecular markers [17]. Microscopic analysis typically shows either multinodular or diffuse proliferation of sparse fibroblasts with extensive hyalinized collagen deposition [18]. Inflammatory infiltrates may include plasma cells, lymphocytes, and occasional eosinophils [18]. IHC staining generally shows positivity for vimentin, smooth muscle-specific actin, and common muscle actin, while being negative for S-100, keratin, and desmin [12].

There are no specific guidelines for managing paratesticular inflammatory pseudotumors; however, treatment typically involves excision with or without testicular preservation. Intraoperative frozen biopsy can help determine if the lesion is benign, potentially preventing unnecessary orchiectomy [15]. Studies have highlighted the value of frozen section assessment in avoiding radical orchiectomy in up to 84% of benign cases [19]. Despite its usefulness, limited literature on the reliability of frozen section biopsy to distinguish these tumors from malignant ones sometimes necessitates orchiectomy, especially in cases of diffuse involvement affecting the testis or indeterminate results [12]. According to the American Urological Association, when a testicular mass is suspected to be a neoplasm, a radical orchiectomy is typically indicated. Additionally, testicular-sparing surgery is generally discouraged and is only appropriate in select patient populations [20].

After a few weeks and before his follow-up appointment, our patient developed backache and leg stiffness. A PET scan was performed and showed high uptake in the left testicular region (Fig. 6). Eventually, the patient underwent left radical orchiectomy. His postoperative histopathological assessment confirmed a paratesticular tumor at the base of the spermatic cord, consisting of spindle-shaped myofibroblastic-like cells associated with chronic inflammatory cell infiltrates, suggestive of a benign paratesticular inflammatory pseudotumor. Most patients have a good prognosis after complete removal, although outcomes may vary depending on tumor characteristics [11]. Regular monitoring, including clinical assessments and surveillance imaging, is advised to evaluate for recurrence or disease progression [11]. Our patient's postoperative course was uneventful, and he was discharged with a follow-up appointment in the urology clinic.

Fig. 6.

Sagittal (A), Coronal (B) and Axial (C) – NM Whole Body FDG PET-CT scan) shows increase uptake in parts of the left scrotal mass with indeterminate background.

Conclusion

Paratesticular inflammatory pseudotumor is an uncommon condition that presents significant challenges in diagnosis and treatment due to its radiographic appearance resembling malignancy. Histopathological analysis is crucial for establishing a definitive diagnosis. Physicians should consider this condition in patients presenting with a hemiscrotal mass. A multidisciplinary approach is essential for providing appropriate patient care.

Patient consent

Written informed consent for the publication of this case report was obtained from the patient.