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Clin Case Rep
Clin Case Rep
10.1002/(ISSN)2050-0904
CCR3
Clinical Case Reports
2050-0904
John Wiley and Sons Inc. Hoboken

10.1002/ccr3.9419
CCR39419
CCR3-2024-05-1484-IV.R2
Oncology
Gastroenterology/Hepatology
Genetics and Genomics
Case Image
Case Image
Chronic painful swelling in the popliteal fossa—A diagnostic challenge
Limaiem et al.
Limaiem Faten https://orcid.org/0000-0003-3805-8390
1 2 fatenlimaiem@gmail.com

Gharbi Mohamed Amine https://orcid.org/0000-0003-0081-1543
1 3
Bouzidi Ramzi 1 3
1 University of Tunis El Manar Faculty of Medicine of Tunis Tunis Tunisia
2 Pathology Department Mongi Slim Hospital La Marsa Tunis Tunisia
3 Department of Orthopedic Surgery Mongi Slim Hospital La Marsa La Marsa Tunisia
* Correspondence
Faten Limaiem, University Hospital Center Mongi Slim, La Marsa, Tunis, Tunisia.
Email: fatenlimaiem@gmail.com

05 9 2024
9 2024
12 9 10.1002/ccr3.v12.9 e941919 8 2024
22 5 2024
26 8 2024
© 2024 The Author(s). Clinical Case Reports published by John Wiley & Sons Ltd.
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the terms of the http://creativecommons.org/licenses/by-nc-nd/4.0/ License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.

Key Clinical Message

The differential diagnoses of popliteal ganglion cysts include Baker's cysts, popliteal artery aneurysms, popliteal tendinitis, popliteal lymphadenopathy, lipomas, and synovial sarcoma.

(A) MRI: coronal T1‐weighted sequences: Polylobulated multilocular thin‐walled cystic formation with liquid‐filled content measuring 100 × 72 × 60 mm, communicating through a small opening with the knee joint (black arrow). (B) MRI: Sagittal T1‐weighted sequences: Polylobulated multilocular thin‐walled cystic formation with liquid‐filled content measuring 100 × 72 × 60 mm, communicating through a small opening with the knee joint (black arrow).

ganglion cyst
pathology
popliteal fossa
surgery
source-schema-version-number2.0
cover-dateSeptember 2024
details-of-publishers-convertorConverter:WILEY_ML3GV2_TO_JATSPMC version:6.4.8 mode:remove_FC converted:06.09.2024
Limaiem F , Gharbi MA , Bouzidi R . Chronic painful swelling in the popliteal fossa—A diagnostic challenge. Clin Case Rep. 2024;12 :e9419. doi:10.1002/ccr3.9419
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pmc1 INTRODUCTION

Different types of cystic masses can occur in the popliteal fossa, including meniscal cysts, synovial cysts, and ganglion cysts. Ganglion cysts are benign masses resulting from collagenous degeneration, causing swelling and pain with restricted knee movement. Diagnosis involves ultrasound and MRI, and surgical removal is often required to prevent recurrence.

2 CASE HISTORY

A 49‐year‐old male patient, with no significant medical history, presented with a progressively painful swelling in the left popliteal fossa over the past 18 months. The patient did not experience fever or deterioration in general health. Physical examination revealed a dry, cold, and non‐swollen left knee with preserved mobility. However, there was moderate limitation in flexion due to posterior pain at the end of the range of motion.

3 METHODS

Laboratory tests yielded normal results without any indications of an inflammatory response. MRI of the left knee revealed a multilocular cystic formation with a thin wall, measuring 100 × 72 × 60 mm, containing liquid content (Figure 1). The cyst was found to communicate with the knee joint through a small opening. No joint effusion was observed. The patient underwent surgery in the prone position with a tourniquet, utilizing Trickey's posterior approach. Dissection of the popliteal neurovascular bundle was performed, followed by a complete resection of the well‐defined cyst (Figure 2). The cyst was primarily located adjacent to the lateral femoral condyle and laterally relative to the tibial insertion of the posterior cruciate ligament. It was closely adherent to the posterior joint capsule without communication, infiltration, or displacement of the surrounding neurovascular and musculoaponeurotic structures. Vascular supply to the cyst was provided by collateral branches of the popliteal artery and vein. The excised cyst, weighing 160 g and measuring 10 × 7 × 3 cm, exhibited a multilocular configuration and contained a viscous gelatinous fluid (Figure 2). Histological examination confirmed the absence of an epithelial lining in the cyst wall, which predominantly consisted of dense fibrous stroma (Figure 3). The cyst lumen showed the presence of myxoid material (Figure 3). The diagnosis was therefore a popliteal ganglion cyst.

FIGURE 1 (A) MRI: Coronal T1‐weighted sequences: Polylobulated multilocular thin‐walled cystic formation with liquid‐filled content measuring 100 × 72 × 60 mm, communicating through a small opening with the knee joint (black arrow). (B) MRI: Sagittal T1‐weighted sequences: Polylobulated multilocular thin‐walled cystic formation with liquid‐filled content measuring 100 × 72 × 60 mm, communicating through a small opening with the knee joint (black arrow).

FIGURE 2 (A) Intraoperative view of the surgical field revealing a prominent ganglionic cyst clearly visible within the popliteal fossa (yellow arrow). (B) Macroscopic features of the popliteal ganglion cyst. The cyst measures 10 × 7 × 3 cm and weighs 160 g, with an intact external surface. (C) Macroscopic features of the popliteal ganglion cyst. On cut section, the cyst reveals a distinctive characteristic: It is filled with a viscous gelatinous fluid (black arrow), consistent with its content. (D) Gross appearance of the popliteal ganglion cyst. On the cut section, the cyst shows a distinct multilocular configuration.

FIGURE 3 (A) Histologic analysis of the popliteal ganglion cyst. The cyst wall is characterized by a dense collagenous structure, lacking a true epithelial lining. Hematoxylin and eosin staining. (Hematoxylin and eosin (H&E), magnification × 100). (B) Histological examination of the popliteal ganglion cyst. The ganglion wall exhibits visible myxoid changes (asterisk), characterized by gray‐blue areas. The remaining portion of the wall is predominantly composed of dense pink collagenous stroma (H&E, magnification × 100). (C) Histologic analysis of the popliteal ganglion cyst. The cyst lumen exhibits the presence of myxoid material (black arrow), (H&E, magnification × 400). (D) Histologic analysis of the popliteal ganglion cyst. The cyst wall reveals the absence of an epithelial lining and is predominantly composed of dense fibrous stroma, (H&E, magnification × 400).

4 CONCLUSION AND RESULTS

The patient had a smooth recovery after the surgery without any complications and is currently being regularly monitored. There was no recurrence after a 3‐month follow‐up period.

5 DISCUSSION

Different types of cystic masses can be found in the popliteal fossa, necessitating precise differentiation for treatment selection. Distinguishing between meniscal cysts, synovial cysts (Baker's cysts), and ganglionic cysts is crucial. 1 MRI is reliable in detecting ganglion cysts as hyperintense lesions on T2‐weighted images, with confirmation based on unique imaging characteristics. 2 While histologic examination is essential for a definitive diagnosis, the management of ganglion cysts varies. Spontaneous resolution is possible, but interventions like aspiration and steroid injections may lead to high recurrence rates. Surgery is considered for persistent or severe cases, aiming for complete excision to minimize recurrence, with an estimated postoperative recurrence rate of 10%–15%. 3

AUTHOR CONTRIBUTIONS

Faten Limaiem: Conceptualization; data curation; formal analysis; investigation; methodology; resources; supervision; validation; visualization; writing – original draft; writing – review and editing. Mohamed Amine Gharbi: Conceptualization; data curation; formal analysis; investigation; methodology; project administration; resources; software; supervision; validation; visualization. Ramzi Bouzidi: Investigation; methodology; project administration; resources; software; supervision; validation; visualization.

FUNDING INFORMATION

We did not receive funding for this article.

CONFLICT OF INTEREST STATEMENT

None declared.

CONSENT

Written informed consent was obtained from the patient to publish this report in accordance with the journal's patient consent policy.

ACKNOWLEDGMENTS

None.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.
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