A 57-year-old man comes to the physician for evaluation of pain and swelling in his right leg. He experienced pain in his right calf the night before that he thought was related to playing softball the previous day. He recalled no injury while playing. The pain progressed and he now has slight swelling in the right foot. The patient has not had a similar problem previously. He has no fever, chills, chest pain, or dyspnea. His other medical problems include hypertension, hyperlipidemia, and degenerative joint disease of both knees.
Vital signs are normal. There is 1+ pedal edema on the right leg and no edema on the left. Peripheral pulses are full and symmetric. There is no obvious difference in temperature between the legs. There is no erythema or palpable cords. Homan's sign is strongly positive on the right. There may be a small effusion of the right knee. The patient has nonpulsatile fullness in the right popliteal fossa when standing with his legs fully extended.
Which of the following is the most likely diagnosis?

Question

A 57-year-old man comes to the physician for evaluation of pain and swelling in his right leg.  He experienced pain in his right calf the night before that he thought was related to playing softball the previous day.  He recalled no injury while playing.  The pain progressed and he now has slight swelling in the right foot.  The patient has not had a similar problem previously.  He has no fever, chills, chest pain, or dyspnea.  His other medical problems include hypertension, hyperlipidemia, and degenerative joint disease of both knees.
Vital signs are normal.  There is 1+ pedal edema on the right leg and no edema on the left.  Peripheral pulses are full and symmetric.  There is no obvious difference in temperature between the legs.  There is no erythema or palpable cords.  Homan's sign is strongly positive on the right.  There may be a small effusion of the right knee.  The patient has nonpulsatile fullness in the right popliteal fossa when standing with his legs fully extended.
Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec193a_9927_7446_853d_f17f8c0ccf10_MD0002_00 This patient's presentation is consistent with a popliteal synovial cyst (Baker's cyst). The clinical features of these cysts are dependent on their size, associated joint pathology, and complications (eg, dissection or rupture). Patients may be asymptomatic or have posterior knee fullness, pain, and/or stiffness increased by activity. Dissecting cysts often result in a "pseudo-thrombophlebitis" syndrome causing exquisite calf tenderness, positive Homan's sign, and mild edema. Physical examination usually shows prominent medial popliteal fullness with the patient standing and knees extended. The swelling tends to decrease with knee flexion to 45º (Foucher's sign). Diagnosis is usually made clinically on physical examination, but ultrasonography can help differentiate between thrombophlebitis and a dissecting synovial cyst. MRI may be required in cases with inconclusive ultrasound or suspected internal knee derangement. Asymptomatic cysts usually require no treatment. Symptomatic cysts are usually managed with rest, elevation, and treatment of the underlying disorder. Symptomatic cysts with dissection sometimes require knee arthrocentesis with intra-articular corticosteroids. Surgery is reserved for patients with persistently symptomatic cysts or who develop decreased knee mobility. (Choice A) Both deep venous thrombosis and dissecting synovial cysts can present with swelling, warmth, tenderness, and positive Homan's sign. However, this patient's posterior knee fullness, knee effusion, and absence of a palpable cord favors a dissecting cyst. (Choice B) Although this patient has several risk factors for arterial disease, popliteal aneurysm usually presents with a pulsatile mass on examination of the popliteal fossa. (Choice D) A sarcoma or other tumor is less common than popliteal cyst but can sometimes present with a solid fullness in the popliteal space. However, this patient's underlying knee osteoarthritis with acute worsening of symptoms makes dissecting synovial cyst more likely. (Choice E) Torn head of the gastrocnemius usually presents with localized pain, decreased mobility, and possible hematoma. It is usually not associated with knee swelling as seen in this patient. Educational objective: Popliteal cysts usually present in patients with underlying knee disease and can be asymptomatic. Patients with symptomatic cysts may have posterior knee fullness, pain, and/or stiffness increased by activity. Popliteal cysts may also dissect or rupture, resulting in calf pain that mimics thrombophlebitis. __________ References: The popliteal cyst. (http://www.ncbi.nlm.nih.gov/pubmed/16362357) Popliteal cysts in adults: a review. (http://www.ncbi.nlm.nih.gov/pubmed/11590580) The pseudothrombophlebitis syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/846388)

A 57-Year-Old Man Comes to the Physician for Evaluation of Pain