易與腹股溝疝氣混淆之巨大陰囊脂肪肉瘤

吳冠儒¹、許炯明¹

¹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

Easily confused of huge scrotal mass between inguinal hernia versus liposarcoma

Kuan-Ju Wu¹, Jong-Ming Hsu¹

¹Department of Urology, MacKay Memorial Hospital, Taipei, Taiwan

Introduction –

Liposarcomas are malignant tumors arising from adipose tissue, with the well-differentiated type (WDLPS), often termed Atypical Lipomatous Tumor (ALT) in peripheral sites, representing a locally aggressive entity. This report details the diagnosis and management of a huge inguinal-scrotal mass, initially suspected to be a hernia, in a 73-year-old male with an extremely high comorbid burden, including metastatic Prostate Carcinoma (Stage 4) and Bronchogenic Carcinoma. The case highlights the potential for misdiagnosis of giant spermatic cord liposarcoma and the challenges associated with managing a large soft tissue sarcoma in a medically complex patient.

Case presentation –

A 73-year-old male with a significant history of metastatic cancers, congestive heart failure, and old CVA presented with a left inguinal bulging mass. Abdominal CT showed focal peritoneal fat tissue trapping into the left inguinal canal, causing slight bulging of the left inguinal region and scrotum, with clinical correlation recommended. Scrotal ultrasound indicated compression of the left testicle and suggested a large left scrotal inguinal hernia or other lesion. Based on the clinical presentation and imaging, the patient was scheduled for left herniorrhaphy. Intraoperatively, a huge bulging mass was encountered, severely compromising the spermatic cord and making identification difficult. Due to the mass size and complexity, the incision was converted to a scrotal approach for debulking and dissection along the natural plane from the normal testicle region.

Result –

The surgical pathology confirmed the mass as an Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma (ALT/WDLPS) of the left inguinal and scrotal soft tissue. The excised specimen was massive, consisting of three pieces of fatty tissue measuring up to 11 x 8.2 x 6.5 cm. Microscopically, the tumor was a well-defined lipomatous lesion composed of univacuolated fat cells of various sizes, with slightly pleomorphic and hyperchromatic nuclei. Immunohistochemistry showed positivity for MDM2, CDK4, and p16 (nuclear). The final note justified retaining the term WDLPS for this spermatic cord lesion due to its potential for disease progression. While the tumor was well demarcated, atypical adipose tissue was focally present at the surgical margin. However, the actual surgical margin could not be fully evaluated due to tissue fragmentation.

Discussion –

This case underscores the critical importance of maintaining a high index of suspicion for primary soft tissue tumors, such as liposarcoma, when evaluating large inguinal or scrotal masses, even when clinical and initial imaging findings suggest a common entity like a complicated hernia. The location of the tumor in the spermatic cord dictates the use of the WDLPS designation, acknowledging its local aggressiveness and potential for dedifferentiation. The positive status of MDM2 and CDK4 confirmed the molecular signature of this low-grade liposarcoma. Given the fragmentation and the presence of atypical tissue at the margin, the patient is at a high risk for local recurrence. The complex management of this localized malignancy must be integrated with the patient’s existing burden of metastatic prostate and bronchogenic carcinomas, necessitating close oncological and surgical follow-up.