以腹股溝疝氣為初始表現之21歲男性腹股溝管高惡性度肉瘤復發：病例報告與文獻回顧

陳冠宇^1,2、陳順郎^1,2、陳文榮^1,2、謝佐宜^1,2、楊旻鑫^1,2、宋文瑋^1,2、何承儒^1,2、王紹全^1,2

¹中山醫學大學附設醫院泌尿科；²中山醫學大學醫學院

High-grade sarcoma recurrence in the inguinal canal initially presenting as an inguinal hernia in a 21-year-old male: A case report and literature review

Kuan Yu Chen^1,2, Sung Lang Chen^1,2, Wen Jung Chen^1,2, Tuzo Yi Hsieh^1,2, Ming Hsin Yang^1,2, Wen Wei Sung^1,2, Cheng Ju Ho^1,2, Shao Chuan Wang^1,2

¹Department of Urology, Chung Shan Medical University Hospital, Taichung, Taiwan.  ²School of Medicine, Chung Shan Medical University Hospital, Taichung,

Introduction:

        Primary soft tissue sarcomas (STS) of the inguinal canal and spermatic cord are exceedingly rare, accounting for less than 1% of all adult malignancies. Among these, liposarcomas are the most common histological subtype. Because their clinical presentation perfectly mimics that of an indirect inguinal hernia or lipoma, they are frequently misdiagnosed, leading to inadvertent "whoops" surgeries where the tumor is partially excised or disrupted during a routine herniorrhaphy. This case report details the challenging trajectory of a young adult initially treated for an inguinal hernia, who subsequently developed a high-grade, MDM2-positive sarcoma recurrence requiring extensive salvage surgery and complicated by severe postoperative wound infection.

Case presentation:

A 24-year-old male with no significant prior medical history presented to a local hospital in early 2022 with a painless, reducible right inguinal bulging mass. Under the clinical impression of a right inguinal hernia, he underwent an elective hernioplasty on April 8, 2022. Unexpectedly, the pathological examination of the excised preperitoneal tissue revealed a myxoid pleomorphic liposarcoma. Seeking specialized oncological care, the patient was referred to our institution. Following multidisciplinary tumor board review, a left subclavian Port-A catheter was implanted on May 3, 2022. He subsequently underwent three courses of concurrent chemoradiotherapy (CCRT), receiving a total radiation dose of 6600 cGy in 33 fractions, completed in June 2022 [Figure 1]. The patient underwent rigorous post-treatment surveillance in our outpatient clinic. He remained clinically and radiographically free of disease until December 2025, when he presented with a palpable abnormality near the right external inguinal ring [Figure 2]. A biopsy performed on December 31, 2025, confirmed a recurrence of high-grade sarcoma. Subsequent restaging computed tomography (CT) in March 2026 revealed an enhancing lesion within the right pectineus muscle, consistent with local tumor recurrence invading the deep connective tissues of the right lower limb and hip region [Figures 3 & 4]. Following shared decision-making regarding the risks of salvage surgery in a previously irradiated field, an elective wide surgical resection of the recurrent soft tissue malignant neoplasm was performed on March 4, 2026. Pathological Findings of the Recurrence: Immunohistochemical (IHC) staining of the resected specimen demonstrated the following profile: Positive for MDM2 and negative for S100, CDK4, SMA, MyoD1, Myogenin, P16, and CD34. The morphology and MDM2 amplification were compatible with a high-grade sarcoma, highly indicative of dedifferentiated liposarcoma progression.

Following discharge, the patient developed a poorly healing wound at the surgical site, accompanied by a malodorous, purulent discharge. He was readmitted in late March 2026. Pus cultures grew Enterococcus avium and Enterococcus faecalis. He was promptly started on targeted intravenous antibiotic therapy and underwent aggressive local wound care. He is currently recovering under close clinical observation.

Discussion and literature review:

Epidemiology and the Diagnostic Dilemma: Primary sarcomas of the inguinal canal and paratesticular tissues are exceedingly rare, representing only 1% to 2% of all urologic malignancies and less than 1% of all adult soft tissue sarcomas (STS) [1,2]. They originate from the mesenchymal elements of the spermatic cord, epididymis, or enveloping fascial layers. Liposarcoma is the most prevalent histological subtype in this region, accounting for approximately 20% to 32% of paratesticular sarcomas in adults [3]. The most treacherous aspect of an inguinal liposarcoma is its clinical presentation. Because these tumors grow insidiously within the restricted space of the inguinal canal, they perfectly mimic benign conditions. Literature indicates that up to 70% to 80% of inguinal sarcomas are preoperatively misdiagnosed as indirect inguinal hernias, hydroceles, epididymal cysts, or benign cord lipomas [3]. Consequently, patients frequently undergo an inadvertent "whoops" surgery—a routine herniorrhaphy or local excision where the malignancy is incidentally discovered. This unplanned marginal excision inevitably results in positive microscopic margins, tumor bed contamination, and a significantly elevated risk of local recurrence if not followed by immediate oncological re-resection [4]. This case perfectly illustrates this clinical trap, as the true malignant nature of the mass was only discovered post-hernioplasty.

Histopathological Evolution and Molecular Characteristics: Liposarcomas are a heterogeneous group of tumors classified into four main subtypes by the World Health Organization (WHO): well-differentiated (WDLPS), dedifferentiated (DDLPS), myxoid (MLPS), and pleomorphic (PLPS) [5]. The pathological trajectory of the patient in this case is a critical teaching point. The initial pathology was reported as "myxoid pleomorphic liposarcoma," a highly aggressive and rare variant. However, the recurrence three years later presented as a high-grade sarcoma with distinct immunohistochemistry (IHC), which is crucial for narrowing the differential diagnosis [6]: (1) Negative markers: Excluded neural tumors (S100), leiomyosarcoma (SMA), rhabdomyosarcoma (MyoD1, Myogenin), and vascular/solitary fibrous tumors (CD34). (2) MDM2 Positivity: The amplification of the 12q13-15 region, housing the MDM2 and CDK4 genes, is the hallmark of WDLPS and DDLPS. Because true pleomorphic liposarcoma (PLPS) characteristically lacks MDM2 amplification [7], the emergence of an MDM2-positive recurrence strongly suggests that the original tumor may have harbored areas of well-differentiated or dedifferentiated liposarcoma, or that the recurrence represents a dedifferentiated clone. DDLPS frequently recurs as a high-grade, non-lipogenic sarcoma, perfectly aligning with the findings in the right pectineus muscle three years post-treatment.

Surgical Principles and Salvage Resection: The gold standard for localized inguinal and paratesticular sarcomas is radical inguinal orchiectomy with high ligation of the spermatic cord at the deep inguinal ring, combined with wide local excision of surrounding soft tissues [8]. Scrotal violation or trans-scrotal biopsies are strictly contraindicated, as they alter lymphatic drainage and necessitate subsequent hemiscrotectomy. In cases of initial non-oncological "whoops" surgeries, standard of care mandates wide local re-excision of the surgical bed to achieve negative margins (R0 resection) [3,4]. Managing a local recurrence—especially in deep pelvic or thigh musculature like the pectineus muscle—requires highly complex salvage surgery. The surgical margins are often strictly constrained by critical neurovascular structures, such as the femoral vessels and the obturator nerve, making definitive clearance in the groin and pelvis exceptionally difficult.

Adjuvant Therapy and Postoperative Morbidity in Irradiated Fields: The role of adjuvant therapy in paratesticular liposarcomas is extrapolated from extremity STS guidelines. Adjuvant radiation therapy (RT) is highly recommended for large (>5 cm), deep-seated, or high-grade tumors, or when surgical margins are close or positive [8,9]. Due to the initial hernioplasty, our patient appropriately received 6600 cGy of concurrent chemoradiotherapy (CCRT) to maximize local control. However, high-dose pelvic and groin radiation exacts a heavy toll on local tissue architecture. Radiation induces obliterative endarteritis, resulting in chronic tissue hypoxia, microvascular thrombosis, and fibrosis [10]. When salvage surgery is performed in this previously irradiated bed, the risk of major wound complications skyrockets, often exceeding 30% to 40% [10,11]. The patient’s readmission for a poorly healing, polymicrobial wound infection driven by Enterococcus avium and Enterococcus faecalis perfectly illustrates this morbidity. The groin is a notoriously challenging site for wound healing due to high friction, moisture, and its proximity to perineal flora. Enterococci are resilient, opportunistic commensal organisms of the gastrointestinal tract. Their presence in a deep surgical space indicates a complex deep space infection exploiting the immunocompromised, poorly vascularized tissue. Management inevitably requires prolonged, culture-directed intravenous antibiotics, meticulous operative debridement, and often, the recruitment of plastic surgery for vascularized flap coverage to introduce a healthy, non-irradiated blood supply to the wound bed.

Prognosis and Surveillance: Due to the anatomical constraints of the inguinal canal, local recurrence rates for paratesticular liposarcomas remain high, ranging from 25% to 37%, even with aggressive therapy. DDLPS carries a particularly guarded prognosis, with a metastatic risk of 15% to 30% and a 5-year overall survival rate hovering around 44% to 60% [2]. Late recurrences (greater than 3 years post-treatment) are well-documented, validating the absolute necessity of stringent, long-term clinical and radiological surveillance, typically extending to a minimum of 10 years.

Conclusion

This case serves as a critical reminder for surgeons and urologists to maintain a high index of suspicion for malignancy when encountering atypical, firm, or recurrent inguinal hernias, particularly in young adults. It highlights the insidious natural history of high-grade and dedifferentiated liposarcomas, which exhibit a strong propensity for late local recurrence despite high-dose adjuvant radiotherapy. Furthermore, clinicians must remain highly vigilant regarding severe postoperative wound complications when performing salvage resections in irradiated groin fields. Managing these complex cases necessitates a coordinated, multidisciplinary approach encompassing surgical oncology, infectious disease, and reconstructive plastic surgery to optimize both oncological outcomes and patient quality of life.

References

1.     Lioe, T. F., & Biggart, J. D. (1993). Tumours of the spermatic cord and paratesticular tissue. A clinicopathological study. British journal of urology, 71(5), 600-606.

2.     Dotan, Z. A., Tal, R., Golijanin, D., Snyder, M. E., Antonescu, C., Brennan, M. F., & Russo, P. (2006). Adult genitourinary sarcoma: the 25-year Memorial Sloan-Kettering experience. The Journal of urology, 176(5), 2033-2039.

3.     Coleman, J., Brennan, M. F., Alektiar, K., & Russo, P. (2003). Adult spermatic cord sarcomas: management and results. Annals of Surgical Oncology, 10(6), 669-675.

4.     Stojadinovic, A., Leung, D. H., Hoos, A., Jaques, D. P., Lewis, J. J., & Brennan, M. F. (2002). Analysis of the prognostic significance of microscopic margins in 2,084 localized primary adult soft tissue sarcomas. Annals of surgery, 235(3), 424-434.

5.     Fletcher, C., Bridge, J. A., Hogendoorn, P. C. W., & Mertens, F. (2013). WHO classification of tumours of soft tissue and bone: WHO classification of tumours, vol. 5. World Health Organization.

6.     Thway, K., & Fisher, C. (2012). Tumors with EWSR1-CREB1 and EWSR1-ATF1 fusions: the current status. The American journal of surgical pathology, 36(7), e1-e11.

7.     Hornick, J. L., Bosenberg, M. W., Mentzel, T., McMenamin, M. E., Oliveira, A. M., & Fletcher, C. D. (2004). Pleomorphic liposarcoma: clinicopathologic analysis of 57 cases. The American journal of surgical pathology, 28(10), 1257-1267.

8.     Ballo, M. T., Zagars, G. K., Pisters, P. W., Feig, B. W., Patel, S. R., & Eschenbach, A. C. V. (2001). Spermatic cord sarcoma: outcome, patterns of failure and management. The Journal of urology, 166(4), 1306-1310.

9.     Hazariwala, R., Morris, C. G., Gilbert, S., Algood, C., & Zlotecki, R. A. (2013). Radiotherapy for spermatic cord sarcoma. American journal of clinical oncology, 36(4), 392–394. https://doi.org/10.1097/COC.0b013e318248dc51

10.   Davis, A. M., O'Sullivan, B., Turcotte, R., Bell, R., Catton, C., Chabot, P., ... & Randomized, N. C. C. T. G. (2005). Late radiation morbidity following randomization to preoperative versus postoperative radiotherapy in extremity soft tissue sarcoma. Radiotherapy and oncology, 75(1), 48-53.

11.   O'Sullivan, B., Davis, A. M., Turcotte, R., Bell, R., Catton, C., Chabot, P., ... & Zee, B. (2002). Preoperative versus postoperative radiotherapy in soft-tissue sarcoma of the limbs: a randomised trial. The Lancet, 359(9325), 2235-2241.