HPI: The patient is a pleasant 21-year-old female who presents with Right foot pain. The patient denies a history of trauma and describes her pain as being diffuse and she states that it began one year ago at which time it was mild and intermittent. She says now her pain has progressively become more intense and more frequent. Presently, she rates her pain a 6 out of 10 and says that it occurs mostly when or after she exercises. She states that she is very athletic, plays intra-mural lacrosse and is a member of a swim club. She denies any history of trauma.

Brief Physical Exam: The patient exhibits an athletic body habitus, weighs approximately 130 lbs, and stands 5’6’’ tall. Upon focused exam of her lower extremities, her pedal pulses are palpable and graded +2/4 bilaterally, CFT is < 3 seconds, with no evidence of edema, erythema or ecchymosis. Manual muscle testing is graded +5/5 upon dorsiflexion, plantarflextion, inversion, and eversion bilaterally. The patient demonstrates pain with palpation along the length of her right 4^th metatarsal, with less pain elicited on palpation of the adjacent intermetatarsal space (Fig. 1). There is no pain on range of motion of the right 4^th metatarsal phalangeal joint. There are no masses palpable and no open lesions. Weight bearing exam demonstrates a slightly valgus heel in resting calcaneal stance position. There is pain in her right foot during ambulation at this time.

Considering the clinical exam presented, and the physical and radiographic findings, how would you proceed in the management of this patient? 

The Conclusion of this case will be posted in an upcoming Residency Insight.

You did not include the Review of Systems.   

Ryan, I find a few things inconsistent w/ the exam and the x-ray. I would like to know if there was any trauma, if there is any temperature difference in the areas of the foot or to the contralateral side, if there is any pain to vibration testing w/ a tuning fork ofver the 4th metatarsal and a gait assesment.  On the x-ray there are two findings that concern me. The more proximal and medial portion look like a stress fracture (healed?) and on the more distal and lateral side the relative radioluceny is unusal. The x-ray looks like a negavite image of gas or myositis ossificans.

Lab work to included CBC w/ diff, CMP, ESR, C-reactive protein and MRI, with & without contrast. I think that does it for now; interesting case, Andrew Levy, DPM

Differential diagnosis would include occult stress fracture vs. bone tumor. It appears there is a cortical thinning and possible stress fracture at the mid shaft of the fourth metatarsal, laterally perhaps as the result of the presence of an expansive intramedullary osseous lesion.  I would consider performing a needle biopsy of the osseous region of interest. A MRI with and without contrast would prove to be beneficial. In addition, Ryan,  on the floroscopy view there appears to be a radiolucent "artifact" outside the region of the metatarsal shaft extending into the intermetatarsal space between the fourth and fifth metatarsals. Based on patient presentation infectious etiology and traumatic etiology is not probable. Tumor differential would include enchondroma, osteoid osteoma, aneurysmal bone cyst, metastatic osseous lesions, Giant cell tumor of tendon and bone, ganglionic cyst, etc. Interesting case, Ryan!

Stress Fracture would be the cheap first visit answer.  However, the x-ray is unusual, and requires further work up.

 After looking at the x-ray I am between 2 differential diagnoses.  A stress fracture is the first thing that comes to mind, secondary to the patients' level of activity.  My second guess would be a bone tumor.  Do a bone scan and an MRI.  A chest X-ray would also be beneficial, I believe.  Is there a family history of cancer?

Ryan,
  Considering the history and the Xrays....................a stress fracture would be in my differential based on her activity level.  However after seeing the lack of edema clinically I tend to lean toward a osseous benign tumor.  I do not think it is an agressive lesion but I would want a bone scan and MRI ordered..................and a bone needle biopsy to follow pending the tests............

Do I see a Codman's triangle proximal to the mass?   Consider a pathological fracture.