CASE REPORT

Ganglion cyst or meniscal cyst—a dilemma!

Vineet Thomas Abraham & M. Chandrasekaran &

R. Nandakumar

Received: 28 February 2013 /Accepted: 29 March 2013# EFORT 2013

Case report

An otherwise healthy 49-year-old gentleman presented toour out-patient clinic with knee swelling since 2 years withassociated pain on squatting and walking long distances. Hegave no history of locking or instability.

On examination, he had a globular swelling on the lateralaspect of the knee, over the lateral joint line about 3×4 cmin size. The swelling was firm in consistency, not mobile,and became more prominent on knee flexion. He had lateraljoint line tenderness. There was slight limitation of flexionwith the range of movement being 0–120°. The tests forstability and the Mc Murray’s test were negative.

Clinical picture with the knee in extension and flexion

Radiographs were normal. MRI revealed a largemultiloculated cystic lesion extending from the lateral me-niscus to the lateral aspect of the knee. The cystic lesion had

high T2 signal intensity and a low T1 signal intensity. Theradiologist suspected it to be a ganglion cyst because of thesize; also, there was no lesion in the lateral meniscus onMRI.

MR images

We decided to an open excision, since the lesion hada large extra articular component. Through a midlineincision, a lateral arthrotomy was done and amultiloculated cyst was seen in the subcutaneous planeon the lateral aspect of the joint, on further dissection, it

V. T. Abraham (*) :M. Chandrasekaran :R. NandakumarMahatma Gandhi Medical College and Research Institute,Pondicherry, Indiae-mail: abrahamvineet@hotmail.com

Eur Orthop TraumatolDOI 10.1007/s12570-013-0186-2

was seen extending through a rent in the lateral capsuleto behind the patellar fat pad and arising from belowthe anterior horn of the lateral meniscus. The large cystwas excised en mass.

Intra OP pictures large meniscal cyst

The cyst was cut open and jelly-like material was seenextruding out. The whole 8×4×3 cm size lesion was sent forhistopathology. The intermeniscal ligament was intact. Noobvious tear was seen in the lateral meniscus. The anteriorhorn of lateral meniscus, which was seen lifted off from thelateral tibial plateau was then sutured back.

Cyst which was excised and sent for histopathology

Discussion

Meniscal cysts are very common, but large meniscalcysts extending to the periphery are very rare. Myxoid

degeneration of collagen leads to intrameniscal cystformation that progresses from the center peripherallyand then outside the meniscus.

A report based on operative specimens after totalmeniscectomies describes intrameniscal cysts prevalenceof 7.1 % [1] and the development into ganglion cysts thatoriginate either from the medial or, more often, from thelateral meniscus is frequently associated with meniscal tears.In many cases, such ganglion cysts progress to the meniscalperiphery, sometimes results in a palpable, tender mass nearthe joint line [1].

Apart from the usual insertion site of meniscal cysts,insertion into the cruciate ligaments, Hoffa's fat pad andpopliteus tendon have also been seen [2–4]. Histologicexamination [4–6] has found evidence of myxoid degen-eration of the ultrastructure of collagen fibers leading toformation of microcysts within the meniscus [6, 7].

In our patient the cyst was seen extending under theanterior horn of the lateral meniscus. Clinically, wewere suspecting the cyst to be a ganglion cyst; theMRI findings also were suggestive of ganglion cyst.The histopathological report mentions it as a meniscalcyst because of the epithelial cell lining which is notseen in ganglion cysts.

Slides showing epithelial cell lining

The usual size of meniscal cysts is <2 cm. Hulet et al., intheir study of lateral meniscal cysts, found the largest axis ofthe cyst, measured in 86 cases, was less than 2 cm [7].

Eur Orthop Traumatol

Jager et al. reported a case of large lateral meniscalcyst, the largest diameter of which was 2.7 cm [8]. Inour case the largest diameter of the cyst was 8cm.Another feature was that the meniscal cyst was notassociated with any meniscal tears.

Large meniscal cysts are quite rare the usual size beingless than 2 cm. We decided to do an open-cyst excisionbecause extent of the cyst was mainly extra-articular, whichcannot be addressed arthroscopically.

Up to the time of the latest follow up, the patient hasimproved symptomatically with no pain. He has a range ofmotion of 0–110°. There is no evidence of recurrence. Insummary, open excision is an acceptable method to treatsuch large lateral meniscal cysts with a major extra-articularcomponent.

The peculiarity in our case is that

1. It presented as a large cystic swelling.2. It had no meniscal lesion which is usually associated

with a meniscal cyst.

Because of these peculiar features, we present this case.

References

1. Lantz B, Singer KM (1990) Meniscal cysts. Clin Sports Med9:707–725

2. Bui-Mansfield LT, Youngberg RA (1997) Intraarticular gangliaofthe knee: prevalence, presentation, etiology, and management.AJR Am J Roentgenol 168:123–127

3. Kim MG, Kim BH, Choi JA (2001) Intra-articular ganglioncysts of the knee: clinical and MR imaging features. EurRadiol 11:834–840

4. Schmitz MC, Schaefer B, Bruns J (1996) A ganglion of theanteriorhorn of the medial meniscus invading the infrapatellarfat pad. Case report. Knee Surg Sports Traumatol Arthrosc4:97–99

5. Ferrer-Rocca O, Vilalta C (1980) Lesions of the meniscus. Part I:macroscopic and histologic findings. Clin Orthop 146:289–300

6. Ferrer-Rocca O, Vilalta C (1980) Lesions of the meniscus. Part II:horizontal cleavages and lateral cysts. Clin Orthop 146:301–307

7. Hulet C, Schiltz D, Locker B, Beguin J, Vielpeau C (1998) Lateralmeniscal cyst. retrospective study of 105 cysts treated with arthros-copy with 5 year follow-up. Rev Chir Orthop Reparatrice ApparMot 84:531–538

8. Jager A, Eberhard C, Hailer NP (2004) Large lateral meniscalganglion cyst extending into the intercondylar fossa of the knee.Arthroscopy 20(61):6–8

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