精索高分化脂肪肉瘤伴隨平滑肌瘤樣及低惡性骨肉瘤樣分化：病例報告與文獻回顧

蘇一廷、鄭鼎耀

台灣基督長老教會馬偕醫療財團法人馬偕紀念醫院 泌尿科

Paratesticular Well-differentiated Liposarcoma with Leiomyomatous and Low-grade Osteosarcomatous Differentiation: A Case Report and Literature Review

Yi-Ting Su, Ting-Yao Cheng

 Department of Urology, MacKay Memorial Hospital, Taipei, Taiwan

Case presentation:

A 68-year-old male with a history of type 2 diabetes mellitus, hypertension, and chronic kidney disease presented with painless enlargement of the left testis persisting for several months. Physical examination revealed an indurated, enlarged, and non-tender mass in the left scrotum, while the right side appeared normal. Scrotal ultrasound was highly suspicious for a left testicular tumor. Preoperative serum tumor markers including Alpha-fetoprotein (AFP), β-HCG, and LDH were all within normal ranges. The patient underwent a left radical orchiectomy via an inguinal approach on March 2, 2026. Intraoperative findings revealed an 8 cm grayish-white, hard tumor located in the paratesticular soft tissue. Pathological analysis confirmed left paratesticular well-differentiated liposarcoma (WDLPS), Histologic Grade 1. The tumor showed mixed sclerosing and inflammatory subtypes with leiomyomatous and low-grade osteosarcomatous differentiation. Immunohistochemistry (IHC) demonstrated overexpression of CDK4 and p16, with a markedly elevated Ki-67 index. A whole abdomen and pelvis CT performed on March 3, 2026, confirmed no grossly enlarged mesenteric lymph nodes and no evidence of distant metastasis or abnormal fluid collection. The imaging showed edematous appearance and subcutaneous emphysema in the left inguinal region, which were compatible with normal postoperative changes. Because the surgical margin was focally involved (R1 margin, <0.1 cm), the patient was diagnosed with Stage 1B disease, the multidisciplinary team discussed options for adjuvant radiation therapy (RT) or close observation. The patient elected for observation, consisting of regular physical examinations and imaging follow-ups every 3 to 6 months.

Discussion:

Paratesticular liposarcomas are rare mesenchymal malignancies, often misdiagnosed as benign conditions like inguinal hernias or lipomas. [1] As seen in this case, normal testicular tumor markers are typical and help differentiate these tumors from germ cell malignancies. While ultrasound is the first-line tool, postoperative CT is essential for accurate staging and distinguishing normal postoperative edema and emphysema from residual disease. Prognosis surgical margin status is the most critical prognostic factor for recurrence. Literature indicates that positive or close margins (<0.1 cm), as observed in this patient, significantly increase the risk of local recurrence compared to negative margins (3-year recurrence-free survival: 54.2% vs. 88.6%). [2] Despite radical inguinal orchiectomy with high ligation of the spermatic cord remains the gold standard of treatment, the role of adjuvant radiation therapy remains controversial; multiple studies have shown no statistically significant benefit in recurrence-free survival, even in patients with positive surgical margins. [3-5]

Paratesticular WDLPS requires high clinical suspicion and careful pathological evaluation. While this patient’s postoperative CT showed no metastasis, the R1 margin status necessitates vigilant long-term follow-up due to the high risk of local recurrence inherent in this malignancy.

Reference:

1.      Ap Dafydd, D., Messiou, C., Thway, K., Strauss, D. C., Nicol, D. L., & Moskovic, E. (2017). Paratesticular sarcoma: typical presentation, imaging features, and clinical challenges. Urology, 100, 163-168.

2.      Kamitani, R., Matsumoto, K., Takeda, T., Mizuno, R., & Oya, M. (2020). Optimal treatment strategy for paratesticular liposarcoma: retrospective analysis of 265 reported cases. International journal of clinical oncology, 25(12), 2099-2106.

3.      Khoubehi B, Mishra V, Ali M, Motiwala H, Karim O. Adult paratesticular sarcomas: update on diagnosis and management. BJU Int. 2020;125(1):30-38.

4.      Lam SW, Kneppers AE, Vriens MR, et al. Spermatic cord sarcoma: a multicenter study of treatment patterns and oncologic outcomes. J Surg Oncol. 2019;120(4):676-682.

5.      Kikuchi R, Morizawa Y, Miura N, et al. Paratesticular well-differentiated liposarcoma: a case report and literature review of recent management strategies. Urol Case Rep. 2023;49:102434.