•
Popliteal Cysts: Presentation as
Thrombophlebitis 1
•
Diagnostic Radiology
Henry A. Swett, M.D., Richard B. Jaffe, M.D., and E. Bruce Mclff, M.D. Synovial-lined cysts in the popliteal space associated with rheumatoid arthritis or meniscal tears may compress the popliteal vein and produce signs and symptoms suggestive of thrombophlebitis. Because of a presumptive diagnosis of thrombophlebitis, venography may be performed initially and demonstrate compression of the popliteal vein by an extrinsic mass. The correct diagnosis of a popliteal cyst can easily be made with B-mode ultrasonography, and, if desired, confirmed by arthrography. Four cases are presented which emphasize these features. INDEX TERMS: Arthritis, rheumatoid. Knee, arthrography. Knee, cysts. Knee, ultrasound. Semilunar Cartilages. Thrombophlebitis. Veins, popliteal. Venography, indications
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Radiology 115:613-615, June 1975
•
with rheumatoid arthritis or meniscal tears may develop synovial cysts in the popliteal space which may compress the popliteal vein and produce signs and symptoms suggestive of thrombophlebitis. Four cases are presented to emphasize this mode of presentation and to illustrate the findings on venography, ultrasonography and contrast arthrography.
P
wrists, and mild rheumatoid deformities in the affected joints. There was swelling and tenderness in the left popliteal fossa and associated minimal left calf tenderness. She was admitted to the hospital with a presumptive diagnosis of thrombophlebitis. A left leg venogram showed narrowing of the left popliteal vein (Fig. 1, A) by an extrinsic mass. There was no evidence of venous thrombosis. An ultrasonic scan of the left popliteal space showed a cystic mass (Fig. 1, B) extending 5.5 em below the knee and measuring 5.0 cm in diameter. The patient was treated conservatively with aspirin with resultant gradual symptomatic improvement.
ATIENTS
CASE REPORTS CASE II: C. B., a 40-year-old man, was admitted with pain in the left popliteal fossa and calf with swelling that had evolved over a one-week period. He had a 10-year history of rheumatoid arthritis affecting primarily the hands, with an increase in symptoms over the last year. One year earlier, he had had thrombophlebitis in the right leg and a pulmonary embolus following an appendectomy. On examination, there was swelling and tenderness in the left calf which was
CASE I: A. H., a 51-year-old white woman, presented with a oneweek history of soreness, warmth, and tenderness in the left popliteal fossa and left leg. The patient had known rheumatoid arthritis for four years in the fingers, wrists, elbows, shoulders, hips, knees, ankles, and toes. Her symptoms were fairly well controlled with aspirin. Physical findings included rheumatoid nodules at both elbows and
Fig. 1. CASE I. A. Note narrowing and lateral deviation of the left popliteal vein by a large popliteal cyst. B. B-mode ultrasound scan of the left popliteal space, prone position, demonstrating a large popliteal cyst. Dense echoes below the cyst represent central osseous and muscular structures. 1 From the Department of Radiology, University of Utah College of Medicine, Salt Lake City, Utah (H. A. S., R. B. J.), and Department of Radiology, Utah Valley Hospital, Provo, Utah (E. B. MeL). Accepted for publication in November 1974. shan
613
614
HENRY
A. SWETT AND OTHERS
June 1975
Fig. 2. CASE II. A. Left oblique projection of the left leg demonstrates narrowing of the popliteal vein by an extrinsic mass. B. Arthrogram of the left knee reveals a popliteal cyst.
one third larger in diameter than the right. There was a small left knee effusion and crepitation of the left patella. Atrophy of the intrinsic musculature of the hands was present with synovial thickening of the wrists and metacarpophalangeal joints. Venography of the left
leg demonstrated a large extrinsic defect with narrowing of the popIiteal vein (Fig. 2, A). A markedly delayed venous run-off was present. There was no evidence of venous thrombosis. A venogram of the right side was normal. A left knee arthrogram (Fig. 2, B) showed evidence of a previous medial meniscectomy and a tear of the lateral meniscus centrally. A large popliteal cyst measuring 8 em in diameter was found and removed at surgery, and consisted of dense collagenous connective tissue consistent with a bursa. CASE III: R R, a 52-year-old man, complained of painful swelling of the right calf. He had a history of rheumatoid arthritis of two years' duration affecting all joints. A diagnosis of right popliteal cyst had been made 18 months previously. Twelve months before admission, he was hospitalized for right calf thrombophlebitis and was treated with anticoagulation. Physical examination revealed right popliteal swelling and a swollen right calf and ankle. There was no deep tenderness; Homans' sign was negative. There was no evidence of acute arthritic change. A venogram showed no evidence of thrombosis but demonstrated an extrinsic pressure defect in the area of the right popliteal fossa (Fig. 3). This caused virtually complete occlusion of the distal deep venous system. The left leg was normal. At operation, a cyst was found in the popliteal space containing yellow fluid and rice bodies. The cyst was pressing against the popliteal vein and occluding it. However, there was no evidence of venous thrombosis and the cyst was removed. Histological examination showed that the cyst wall was lined by synovial and granulation tissue.
Fig. 3. CASE III. Popliteal cyst causing nearly complete obstruction of the right popliteal vein.
CASE IV: G. R, a 55-year-old man, presented with pain in the left knee and swelling of the right calf. He had a history of rheumatoid arthritis for two years affecting hands, wrists, elbows, shoulders, feet and ankles. He was treated at various times with gold, steroids, aspirin, and Indocin with only partial relief of symptoms. Three
Vol. 115
POPLITEAL CYSTS:
PRESENTATION AS THROMBOPHLEBITIS
615
Diagnostic Radiology
Fig. 4. Case IV. A. Popliteal cyst with narrowing and deviation of the left popliteal vein. B. B-mode ultrasound scan, prone position, demonstrating cyst in the popliteal space. months before admission, he noticed swelling of his left leg and an increase in joint symptoms. One month prior to admission he complained of right leg swelling and calf tenderness. He was treated with heparin and warfarin for thrombophlebitis. Venography was performed because of suspected left leg thrombophlebitis. This study (Fig. 4, A) showed patent veins and lateral displacement of the popliteal vein by an extrinsic mass. Ultrasonography showed a cystic mass in the popliteal space measuring 2.5 X 5 cm in length (Fig. 4, B). This was presumed to represent a popliteal cyst and conservative therapy was continued.
DISCUSSION
As the popliteal vein passes through the popliteal space, it crosses over the popliteal artery (4). In the distal portion of the popliteal space, it lies medial to the artery and then becomes superficial to it more proximally. A cyst in the popliteal space may either stretch the vein or compress it against the relatively rigid artery. Although popliteal cysts may rarely form without any apparent cause, they typically are synovial lined cysts associated with a meniscal tear or rheumatoid arthritis (3, 5). The 4 patients presented here all had rheumatoid arthritis. One man (CASE II) also had a meniscal tear. Popliteal cysts commonly cause few symptoms. Mild tenderness and swelling are frequently the only complaints (4). Occasionally, more severe pain and swelling occur and may mimick acute deep vein thrombosis (2, 4). As in our cases, the first diagnostic procedure performed is usually venography. Typically, this study will demonstrate no evidence of venous thrombosis, but will reveal extrinsic compression of the popliteal vein by a
large popliteal cyst. Care must be taken in performing venography with knees slightly flexed. Otherwise, the impression of the posterior flexor muscles may mimick the cyst defect (1). Comparison with the normal side provides a valuable internal standard. Further confirmation of the venographic impression of an extrinsic mass is easily obtained with B-mode ultrasonography. Popliteal cysts appear as a well-circumscribed mass with a sonolucent center. Although usually not necessary for diagnosis, arthrography provides another method of confirmation. Cysts fill with contrast media in virtually all cases and communication with the gastrocnemio-semimembranous bursa is demonstrated in 7-42 % of all knee arthrograms (5).
Department of Radiology University of Utah Medical Center Salt Lake City, Utah 84132
REFERENCES 1. Alman T, Nylander G: False signs of thrombosis in lower leg phlebography. Acta Radiol [Diag] 2:345-352, Jul 1964 2. Bowerman JW, Muhletaler C: Arthrography of rheumatoid synovial cysts of the knee and wrist. J Can Assoc Radiol 24:24-32, Mar 1973 3. Doppman JL: Baker's cyst and the normal gastrocnemiosemimembranous bursa. Am J RoentgenoI94:646-652, Jul1965 4. Good AE: Rheumatoid arthritis, Baker's cyst, and "thrombophlebitis." Arthritis Rheum 7:56-64, Feb 1964 5. Wolfe RD, Colloff B: Popliteal cysts. An arthrographic study and review of the literature. J Bone Joint Surg 54A:1057-1063, Jul 1972
Popliteal Cysts: Presentation as
Thrombophlebitis 1
•
Diagnostic Radiology
Henry A. Swett, M.D., Richard B. Jaffe, M.D., and E. Bruce Mclff, M.D. Synovial-lined cysts in the popliteal space associated with rheumatoid arthritis or meniscal tears may compress the popliteal vein and produce signs and symptoms suggestive of thrombophlebitis. Because of a presumptive diagnosis of thrombophlebitis, venography may be performed initially and demonstrate compression of the popliteal vein by an extrinsic mass. The correct diagnosis of a popliteal cyst can easily be made with B-mode ultrasonography, and, if desired, confirmed by arthrography. Four cases are presented which emphasize these features. INDEX TERMS: Arthritis, rheumatoid. Knee, arthrography. Knee, cysts. Knee, ultrasound. Semilunar Cartilages. Thrombophlebitis. Veins, popliteal. Venography, indications
•
Radiology 115:613-615, June 1975
•
with rheumatoid arthritis or meniscal tears may develop synovial cysts in the popliteal space which may compress the popliteal vein and produce signs and symptoms suggestive of thrombophlebitis. Four cases are presented to emphasize this mode of presentation and to illustrate the findings on venography, ultrasonography and contrast arthrography.
P
wrists, and mild rheumatoid deformities in the affected joints. There was swelling and tenderness in the left popliteal fossa and associated minimal left calf tenderness. She was admitted to the hospital with a presumptive diagnosis of thrombophlebitis. A left leg venogram showed narrowing of the left popliteal vein (Fig. 1, A) by an extrinsic mass. There was no evidence of venous thrombosis. An ultrasonic scan of the left popliteal space showed a cystic mass (Fig. 1, B) extending 5.5 em below the knee and measuring 5.0 cm in diameter. The patient was treated conservatively with aspirin with resultant gradual symptomatic improvement.
ATIENTS
CASE REPORTS CASE II: C. B., a 40-year-old man, was admitted with pain in the left popliteal fossa and calf with swelling that had evolved over a one-week period. He had a 10-year history of rheumatoid arthritis affecting primarily the hands, with an increase in symptoms over the last year. One year earlier, he had had thrombophlebitis in the right leg and a pulmonary embolus following an appendectomy. On examination, there was swelling and tenderness in the left calf which was
CASE I: A. H., a 51-year-old white woman, presented with a oneweek history of soreness, warmth, and tenderness in the left popliteal fossa and left leg. The patient had known rheumatoid arthritis for four years in the fingers, wrists, elbows, shoulders, hips, knees, ankles, and toes. Her symptoms were fairly well controlled with aspirin. Physical findings included rheumatoid nodules at both elbows and
Fig. 1. CASE I. A. Note narrowing and lateral deviation of the left popliteal vein by a large popliteal cyst. B. B-mode ultrasound scan of the left popliteal space, prone position, demonstrating a large popliteal cyst. Dense echoes below the cyst represent central osseous and muscular structures. 1 From the Department of Radiology, University of Utah College of Medicine, Salt Lake City, Utah (H. A. S., R. B. J.), and Department of Radiology, Utah Valley Hospital, Provo, Utah (E. B. MeL). Accepted for publication in November 1974. shan
613
614
HENRY
A. SWETT AND OTHERS
June 1975
Fig. 2. CASE II. A. Left oblique projection of the left leg demonstrates narrowing of the popliteal vein by an extrinsic mass. B. Arthrogram of the left knee reveals a popliteal cyst.
one third larger in diameter than the right. There was a small left knee effusion and crepitation of the left patella. Atrophy of the intrinsic musculature of the hands was present with synovial thickening of the wrists and metacarpophalangeal joints. Venography of the left
leg demonstrated a large extrinsic defect with narrowing of the popIiteal vein (Fig. 2, A). A markedly delayed venous run-off was present. There was no evidence of venous thrombosis. A venogram of the right side was normal. A left knee arthrogram (Fig. 2, B) showed evidence of a previous medial meniscectomy and a tear of the lateral meniscus centrally. A large popliteal cyst measuring 8 em in diameter was found and removed at surgery, and consisted of dense collagenous connective tissue consistent with a bursa. CASE III: R R, a 52-year-old man, complained of painful swelling of the right calf. He had a history of rheumatoid arthritis of two years' duration affecting all joints. A diagnosis of right popliteal cyst had been made 18 months previously. Twelve months before admission, he was hospitalized for right calf thrombophlebitis and was treated with anticoagulation. Physical examination revealed right popliteal swelling and a swollen right calf and ankle. There was no deep tenderness; Homans' sign was negative. There was no evidence of acute arthritic change. A venogram showed no evidence of thrombosis but demonstrated an extrinsic pressure defect in the area of the right popliteal fossa (Fig. 3). This caused virtually complete occlusion of the distal deep venous system. The left leg was normal. At operation, a cyst was found in the popliteal space containing yellow fluid and rice bodies. The cyst was pressing against the popliteal vein and occluding it. However, there was no evidence of venous thrombosis and the cyst was removed. Histological examination showed that the cyst wall was lined by synovial and granulation tissue.
Fig. 3. CASE III. Popliteal cyst causing nearly complete obstruction of the right popliteal vein.
CASE IV: G. R, a 55-year-old man, presented with pain in the left knee and swelling of the right calf. He had a history of rheumatoid arthritis for two years affecting hands, wrists, elbows, shoulders, feet and ankles. He was treated at various times with gold, steroids, aspirin, and Indocin with only partial relief of symptoms. Three
Vol. 115
POPLITEAL CYSTS:
PRESENTATION AS THROMBOPHLEBITIS
615
Diagnostic Radiology
Fig. 4. Case IV. A. Popliteal cyst with narrowing and deviation of the left popliteal vein. B. B-mode ultrasound scan, prone position, demonstrating cyst in the popliteal space. months before admission, he noticed swelling of his left leg and an increase in joint symptoms. One month prior to admission he complained of right leg swelling and calf tenderness. He was treated with heparin and warfarin for thrombophlebitis. Venography was performed because of suspected left leg thrombophlebitis. This study (Fig. 4, A) showed patent veins and lateral displacement of the popliteal vein by an extrinsic mass. Ultrasonography showed a cystic mass in the popliteal space measuring 2.5 X 5 cm in length (Fig. 4, B). This was presumed to represent a popliteal cyst and conservative therapy was continued.
DISCUSSION
As the popliteal vein passes through the popliteal space, it crosses over the popliteal artery (4). In the distal portion of the popliteal space, it lies medial to the artery and then becomes superficial to it more proximally. A cyst in the popliteal space may either stretch the vein or compress it against the relatively rigid artery. Although popliteal cysts may rarely form without any apparent cause, they typically are synovial lined cysts associated with a meniscal tear or rheumatoid arthritis (3, 5). The 4 patients presented here all had rheumatoid arthritis. One man (CASE II) also had a meniscal tear. Popliteal cysts commonly cause few symptoms. Mild tenderness and swelling are frequently the only complaints (4). Occasionally, more severe pain and swelling occur and may mimick acute deep vein thrombosis (2, 4). As in our cases, the first diagnostic procedure performed is usually venography. Typically, this study will demonstrate no evidence of venous thrombosis, but will reveal extrinsic compression of the popliteal vein by a
large popliteal cyst. Care must be taken in performing venography with knees slightly flexed. Otherwise, the impression of the posterior flexor muscles may mimick the cyst defect (1). Comparison with the normal side provides a valuable internal standard. Further confirmation of the venographic impression of an extrinsic mass is easily obtained with B-mode ultrasonography. Popliteal cysts appear as a well-circumscribed mass with a sonolucent center. Although usually not necessary for diagnosis, arthrography provides another method of confirmation. Cysts fill with contrast media in virtually all cases and communication with the gastrocnemio-semimembranous bursa is demonstrated in 7-42 % of all knee arthrograms (5).
Department of Radiology University of Utah Medical Center Salt Lake City, Utah 84132
REFERENCES 1. Alman T, Nylander G: False signs of thrombosis in lower leg phlebography. Acta Radiol [Diag] 2:345-352, Jul 1964 2. Bowerman JW, Muhletaler C: Arthrography of rheumatoid synovial cysts of the knee and wrist. J Can Assoc Radiol 24:24-32, Mar 1973 3. Doppman JL: Baker's cyst and the normal gastrocnemiosemimembranous bursa. Am J RoentgenoI94:646-652, Jul1965 4. Good AE: Rheumatoid arthritis, Baker's cyst, and "thrombophlebitis." Arthritis Rheum 7:56-64, Feb 1964 5. Wolfe RD, Colloff B: Popliteal cysts. An arthrographic study and review of the literature. J Bone Joint Surg 54A:1057-1063, Jul 1972
