Korean J Radiol.  2010 Jun;11(3):364-367. 10.3348/kjr.2010.11.3.364.

Mesothelial Cyst of the Round Ligament Mimicking a Metastasis: a Case Report

• Kim BM
• Lee JY
• Han YH
• Kim SY
• Seo JW
• Kim YH
• Cha SJ
• Hur G
• Joo M
• Lee ES

• KMID: 946278
• DOI: http://doi.org/10.3348/kjr.2010.11.3.364

Abstract

A mesothelial cyst of the round ligament is a rare cause of an inguinal mass. Clinically, it is frequently misdiagnosed as one of commoner diseases such as an inguinal hernia, femoral hernia, lipoma, and lymphadenopathy upon physical examination. Some previous reports elaborated the sonographic features of a mesothelial cyst of the round ligament. However, to our knowledge, few reports have described the CT features of a mesothelial cyst. We illustrated here the sonographic and multidetector CT features of a case of a mesothelial cyst of the round ligament that presented as an inguinal palpable mass and mimicked a metastasis in a patient with a Sertoli-Leydig cell tumor of the ovary.

Keyword

Mesothelial cyst; Round ligament; Inguinal area; Ultrasonography; Multi-detector row CT

MeSH Terms

Abdominal Neoplasms/*diagnosis/secondary
Aged
Contrast Media/diagnostic use
Cysts/*radiography/*ultrasonography
Diagnosis, Differential
Epithelium/radiography/ultrasonography
Female
Humans
Ovarian Neoplasms/*pathology
Radiographic Image Enhancement/methods
Round Ligament/*radiography/*ultrasonography
Sertoli-Leydig Cell Tumor/*pathology
Tomography, X-Ray Computed/methods

Figure

• 

  Fig. 1 Mesothelial cyst of round ligament in 76-year-old woman. A. Sagittal ultrasound shows well-circumscribed, oval cystic mass with hypoechoic solid portion (arrows) at left inguinal region. In addition, stalk-like structure (arrowheads) in cranial aspect of mass was also observed. B. Color Doppler ultrasound shows flow signals (arrows) in solid portion and walls of mass. C. Axial contrast enhanced CT shows left inguinal cystic mass (arrows) with hypertrophic wall and internal enhancing solid portion. D. Coronal contrast enhanced CT shows 21×12×10 cm sized multi-locular, well-circumscribed, complex cystic and solid mass (white arrows) extending from right adnexa to upper abdomen. Left inguinal cystic mass (asterisk) was abutted to extraperitoneal portion of round ligament (arrowheads). E. Left ovarian vessels (arrowheads) are located apart from inguinal cystic mass. In addition, unusually thick, round ligament (arrow) is noted just proximal to inguinal canal. F. Photomicrograph showing diffuse stromal edema, inflammatory cell infiltration, and mesothelial cell proliferation in round ligament adjacent to cyst lined by mesothelial cells (Hematoxylin & Eosin staining, ×100). Immunostaining of WT-1 and mesothelial cell marker highlight cyst-lining mesothelial cells (arrow) (inset, ×200).

Reference

1. Harper GB Jr, Awbrey BJ, Thomas CG Jr, Askin FB. Mesothelial cysts of the round ligament simulating inguinal hernia. Report of four cases and a review of the literature. Am J Surg. 1986. 151:515–517.

2. Oh SN, Jung SE, Rha SE, Lim GY, Ku YM, Byun JY, et al. Sonography of various cystic masses of the female groin. J Ultrasound Med. 2007. 26:1735–1742.

3. Warshauer DM, Mandel SR. Leiomyoma of the extraperitoneal round ligament: CT demonstration. Clin Imaging. 1999. 23:375–376.

4. Oh SN, Jung SE, Lee JM, Chung JH, Park GS. Sonographic diagnosis of a round ligament cyst in the inguinal area. J Clin Ultrasound. 2007. 35:226–228.

5. Khanna PC, Ponsky T, Zagol B, Lukish JR, Markle BM. Sonographic appearance of canal of Nuck hydrocele. Pediatr Radiol. 2007. 37:603–606.

6. Park SJ, Lee HK, Hong HS, Kim HC, Kim DH, Park JS, et al. Hydrocele of the canal of Nuck in a girl: ultrasound and MR appearance. Br J Radiol. 2004. 77:243–244.

7. Stickel WH, Manner M. Female hydrocele (cyst of the canal of Nuck): sonographic appearance of a rare and little-known disorder. J Ultrasound Med. 2004. 23:429–432.

8. Ryley DA, Moorman DW, Hecht JL, Alper MM. A mesothelial cyst of the round ligament presenting as an inguinal hernia after gonadotropin stimulation for in vitro fertilization. Fertil Steril. 2004. 82:944–946.

9. Cervini P, Mahoney J, Wu L. Endometriosis in the canal of Nuck: atypical manifestations in an unusual location. AJR Am J Roentgenol. 2005. 185:284–285.

10. Yang DM, Kim HC, Jin W, Ryu CW, Ryu JK, Nam DH, et al. Inguinal endometriosis presenting as a multicystic mass on sonography. J Ultrasound Med. 2007. 26:1449–1451.