A 38-year-old man comes to the office due to a 2-month history of an enlarging, localized swelling on the left foot. Tying his shoelaces too tight leads to localized pain and numbness in the third and fourth toes. Examination shows a firm, nontender, well-circumscribed lesion on the dorsum of the foot as shown in the exhibit.
The lesion transilluminates when a penlight is applied to it. Without treatment, which of the following is most likely to occur in this patient?

Question

A 38-year-old man comes to the office due to a 2-month history of an enlarging, localized swelling on the left foot.  Tying his shoelaces too tight leads to localized pain and numbness in the third and fourth toes.  Examination shows a firm, nontender, well-circumscribed lesion on the dorsum of the foot as shown in the exhibit. 
 The lesion transilluminates when a penlight is applied to it.  Without treatment, which of the following is most likely to occur in this patient?

Quizplus · Accepted Answer

11ec160b_3a58_eb5c_9249_b1a7a22efe6d_MD0001_00 This patient has a ganglion cyst, an outpouching of connective tissue arising from tendon sheaths, joint structures (eg, joint capsule), or bursae. Clear mucinous or gelatinous fluid accumulates in the sac, giving rise to a round, well-circumscribed, firm cyst that transilluminates on penlight examination. Ganglion cysts are most common on the dorsal and volar wrists, but dorsal foot lesions are also common. Most ganglion cysts resolve spontaneously and do not require specific treatment. Cysts that raise cosmetic concerns or cause pain or paresthesia (due to nerve compression) can be treated with needle aspiration if desired. However, recurrence is common, and patients may eventually require surgical excision. (Choice A) Bloodstream infection (bacteremia) can be a complication of cutaneous abscess, which also presents as localized swelling. Unlike a ganglion cyst, an abscess is red, painful, and fluctuant on palpation. Because of the collection of pus (an opaque liquid), an abscess does not transilluminate. (Choice B) Gouty tophi are hard, irregular, subcutaneous collections of uric acid crystals found in patients with gout. Because of its solid nature, a gouty tophus does not transilluminate. (Choice C) This patient's ganglion cyst is causing compression of dorsal cutaneous nerves (sensory branches of superficial peroneal nerve), leading to paresthesia. However, these branches do not contain motor fibers and so the patient is not at risk for paralysis. (Choice D) Synovial sarcoma can present as a mass adjacent to a joint in a young adult; however, due to its solid nature, it does not transilluminate. Educational objective: A ganglion cyst is a connective tissue outpouching arising from tendon sheaths and joint structures. It is typically round, firm, well-circumscribed, and transilluminates on penlight examination. Most resolve spontaneously. __________ References: Treatment of ganglion cysts. (http://www.ncbi.nlm.nih.gov/pubmed/24967120)

A 38-Year-Old Man Comes to the Office Due to a 2-Month