Author: Kevin Stephens, Jr, MD, MBA
Co Author #1: Justin A Mullner, MD

Patient Presentation:
A 28 year old active medical student presented with a 2 year history of progressively worsening right leg pain, weakness, and paresthesia.

History:
Around 2 years prior to presenting, the student noted short lasting pain and paresthesia near the head of the fibula on his right leg with incidental contact to that area or during vigorous physical activity. He denied knowing any single inciting event. Since that time, his symptoms became progressively worse and occurred more frequently, limiting his physical activity. In the months prior to presenting, he also noticed a slow growing, tender flesh colored nodule near the head of his fibula. Additionally, he began to notice increased weakness with dorsiflexion of his right ankle that would cause him to intermittently trip when walking up stairs. He thought his symptoms were caused by peroneal nerve entrapment so he tried rest, targeted physical therapy, and NSAIDs which helped minimally. His symptoms returned when he resumed physical activity. He presented to the sports medicine clinic when he noted that his symptoms would occur for up to a week at a time without improvement, even with minimal physical activity. By the time of presentation, the nodule was 1 cm, his paresthesia radiated to his foot, and he was unable to complete moderate physical activity due to weakness, pain, and paresthesia.

Physical Exam:
Cardiovascular: No cyanosis, 2 second capillary refill distal to site of injury. Neurological: No focal deficit appreciated, full light touch and motor strength distal to site of injury, 2+ patellar reflexes bilaterally, symmetric without abnormalities. Right knee: Small swelling noted laterally around the fibular head, no effusion, paresthesia induced with compression of swelling over fibular head, full knee range of motion, 5/5 strength of knee with flexion/extension. 2+ dorsalis pedis and posterior tibial pulses bilaterally, Lachman negative, Varus/Valgus stress test negative, Anterior Drawer negative, Posterior Drawer negative, McMurray negative.

Click here to continue. Challenge yourself by writing down a broad differential diagnosis before moving to the next slide.