P3A356: Hips Don't Lie: The Importance of Your Differential Diagnosis

Introduction: Children and adolescents are now practicing more sports at competitive levels. This has increased the number of musculoskeletal complaints seen by physicians. However, it is still important to consider several differential diagnoses when dealing with patients with persistent pain. We present the case of a previously healthy 20-year-old female presenting to the emergency department with 6 months of progressive left hip pain.

Case Description: Patient is a previously healthy 20-year-old female, who plays softball for her university, presenting with 6 months of progressive left hip pain. Pain is localized on her left outer hip, radiating anteriorly to the left quadriceps and posteriorly to the left glute. Initially pain was moderate, 4/10 on the numerical rating scale, however, has now reached 10/10 levels. Symptoms worsen towards the end of the day and aggravate with physical activity. This past week she has been using crutches. During her softball career, she has experienced several lesions, such as a flexor muscle strain, and she claims this pain does not feel the same as her previous injuries. Older brother has a history of Burkitt’s lymphoma, and the younger brother was recently diagnosed with skin cancer at 13 years of age. Maternal grandmother had breast and uterine cancer diagnosed initially at 36 years of age. There are no other symptoms associated. On exam, there is no swelling, erythema or deformity noted however there is severe decrease range of motion of left hip and inability to bear weight. During the past 6 months, the patient has been evaluated by several physicians, who considered the pain to be muscular in origin. She has been doing rehabilitation and several types of physical therapy with no improvement. She has also tried several pain medications, including cannabis, with no major improvement. Imaging done showed a solid mass in the left femur. Biopsy report confirmed a Ewing Sarcoma. Li-Fraumeni testing was negative.

Discussion: Injuries to the hip and groin may account for up to a quarter of injuries seen in athletic children and can usually be acute or chronic. There are several different components that can be affected such as bone, cartilages, ligaments, or muscles. However, as physicians, we should keep in mind the possibility of non-sports-related pathology, especially when pain is unresponsive to initial therapies or progressive. Differential diagnosis such as tumors, infections, avascular necrosis or femoroacetabular impingement should be considered and ruled-out.

Conclusion: This case presents a patient with persistent pain, who had a delayed malignancy diagnosis. Sport injuries can sometimes be misleading, highlighting the importance of the clinical history, constant monitoring, and timely referral when there is evolving or non-responsive pain. Tumors should be considered in the young athlete with atraumatic hip and groin pain.