Abstract
Testicular fibrous pseudotumor is a rare benign disease that is often misdiagnosed as testicular malignancy before surgery. We present a case of a 38-year-old male who had painless palpable masses in the left scrotum. Testicular tumor marker levels were within normal limits, and ultrasound revealed paratesticular masses. Intraoperative rapid diagnosis indicated a fibrous pseudotumor without malignancy. We successfully removed all the masses, along with the testis and a portion of the spermatic cord sheath, avoiding unnecessary orchiectomy.
Introduction
Testicular fibrous pseudotumor is a rare multifocal inflammatory fibroproliferative disease, which presents as a painless scrotal mass and is often misdiagnosed as testicular malignancy, leading to unnecessary orchiectomy (Jha et al., 2009; Sadowski et al., 2001). In December 2021, one case was admitted to our hospital, and the report is presented below.
Case Presentation
A 38-year-old man discovered a soybean-sized mass in his left scrotum 1 year ago. The mass was hard and did not cause pain or discharge. Over time, the tumor grew to the size of a peanut, and multiple new tumors developed around it. The patient did not experience fever, testicular or scrotum swelling, pain, dysuria, or hematuria. Upon physical examination, the penis and scrotum were normal in development, but multiple bead-like tumors were observed in the left scrotum, with the largest measuring 1.0 × 0.8 cm in size. The texture of the tumors was hard, and they had good mobility, a smooth surface, and no tenderness. The relationship between the tumor and testis was unclear, and no apparent abnormalities were detected in the contralateral testis and scrotum. There was no palpable lymph node enlargement in either groin.
Laboratory tests for testicular-related tumors, including alpha fetoprotein, carcinoembryonic antigen, and human chorionic gonadotrophin, showed no abnormalities. Routine semen was normal, and antibody binding and tuberculin purified protein derivative tests were negative. B-ultrasound imaging revealed multiple heterogeneous echo nodules in the left testicular sheath cavity parietal sheath, with the largest measuring about 1.3 × 0.8 cm in size. The boundary was still clear, the shape was regular, and the internal echo was not uniform. No obvious blood flow signal was detected, and no apparent abnormalities were detected upon examination of the contralateral testis and scrotum. There were no palpable lymph nodes in either inguinal region. The diagnosis was multiple nodules in the sheath cavity of the left testis, the nature of which was yet to be determined (Figure 1). CT scans showed small nodules with iso/slightly low density in the left testis that were not clearly displayed on plain scans and no apparent abnormalities were observed in the contralateral testis and scrotum. However, mild enhancement was observed on enhanced scans, and the diagnosis was nodules in the left testis, with a possibility of tumors. Preoperative preparations were made, and scrotal exploration was planned to prepare for a left orchiectomy.

B-Ultrasound Imaging Revealed Multiple Heterogeneous Echo Nodules in the Left Testicular Sheath Cavity Parietal Sheath. The Boundary Was Still Clear, the Shape Was Regular, and the Internal Echo Was Not Uniform. No Obvious Blood Flow Signal Was Detected
During the operation, dozens of beaded nodules were observed in the parietal layer of the left testis. The nodules varied in size and were off-white, tough, and smooth. Postoperative pathology determined that the lesion was consistent with a fibrous pseudotumor of the testicular sheath (Figure 2). Follow-up after 1 year showed no recurrence, complications, or need for further treatment.

(A) Intraoperative Picture of the Left Testis With Masses. (B) Hematoxylin and Eosin, Original Magnification 200×. Densely Hyalinized Fibrous Tissue With Scattered Aggregates of Chronic Inflammatory Cells
Discussion
Testicular fibrous pseudotumor is a rare benign lesion that originates from the tunica vaginalis and affects the testicular tunica, albuginea, epididymis, and spermatic cord. Its etiology is not fully understood, but trauma or inflammation may play a role in its development (Mostofi, 1973). In recent years, some studies have suggested that fibrous pseudotumor may be associated with IgG4-related sclerosis due to the presence of IgG4-stained plasma cells in the lesions (Dieckmann et al., 2013; Kim et al., 2015).
The disease is most commonly seen in young and middle-aged men around 30 years old, but cases have been reported in patients between 7 and 95 years of age. The lesion is tough and appears as a diffuse or focal nodular fibrous tissue hyperplasia. The lesion can range in size and may accumulate in various parts of the testicular area. The pathological features of fibrous pseudotumor may be difficult to distinguish from inflammatory pseudotumor (Thompson & van der Walt, 1986). Collagen fibers arranged in parallel are common in most fibrous pseudotumors, and lymphocytes and plasma cells can be seen in the center. Some fibrous pseudotumors may contain more fibroblasts, myofibroblasts, or fibrous xanthoma structures.
B-ultrasound is the primary diagnostic tool used for this condition, with the main sonographic features being as follows: Nodular type: multiple solid nodules are present in the testicular sheath area, mostly oval in shape, with clearer boundaries and different echogenicity. These nodules and calcifications do not move with the movement of the epididymis and testis, and some nodules may show color blood flow signals in the form of dots and short rods. Diffuse type: the testicular sheath is irregularly thickened and shows heterogeneous echogenicity. In some patients, calcifications with echogenicity that do not change with changes in body position may be seen, and a few point and short rod-shaped blood flow signals may be observed on the thickened testicular sheath. A small amount of effusion can also be seen in the testicular cavity of the affected side in most patients.
Surgical resection of the affected testicular sheath and spermatic cord sheath is sufficient for the treatment of testicular fibrous pseudotumor. In clinical practice, it is often misdiagnosed as a malignant testicular tumor, which leads to unnecessary surgical resection of the testis or epididymis. Intraoperative frozen pathology is crucial in avoiding unnecessary radical surgery. The prognosis of this disease is good, and there are no reported cases of recurrence in many studies.
This article also has some limitations. For example, we did not consider the possibility of testicular sheath fibrous pseudotumor before surgery, so we did not perform IgG-related laboratory tests, which resulted in incomplete case integrity. Second, the patient did not return to the hospital for follow-up, so we could not evaluate the patient’s prognosis in detail. Third, the number of cases of testicular sheath fibrous pseudotumor is too small to be convincing. In the future, we will continue to pay attention to this disease and expand our sample size.
Conclusion
In summary, testicular fibrous pseudotumor is a rare benign testicular disease that affects young and middle-aged men. Testicular ultrasound and magnetic resonance imaging are helpful in diagnosing this condition. The key to successful treatment is the surgical removal of the nodular lesions and affected testicular sheath, while avoiding misdiagnosis as testicular malignancy, which could result in unnecessary orchiectomy.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
Patient Consent Statement
The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. Written informed consent for the publication of the report and the accompanying images was provided by the patient. The submission version of the report was read by himself, and the report’s content was confirmed as being correct to the best of his knowledge. Informed consent was obtained from the patients.
