A 10-year-old boy, previously well, presents with an 8 month history of right hip pain, which he attributes to a fall. He also reports significant weight loss and complains of fatigue and pallor .

The boy appears chronically ill. He is cachectic with no subcutaneous fat and severely reduced muscle bulk. There is a large mass arising from the right hip and extending to the perineum and the right buttock, with resultant swelling of the right leg (Fig. 7.1). The right hip is kept in abduction and the patient does not tolerate any movement of the hip. A 90° flexion contracture of the right knee is present. On abdominal examination the mass is also palpable in the right fossa iliaca. There are no paresthesias and he has normal dorsiflexion of the right foot. There is no hepatosplenomegaly. The respiratory examination is normal. The patient is mildly tachycardic, but otherwise the cardiovascular system is also normal. He appears withdrawn and depressed, but otherwise there are no neurological abnormalities.

What is the possible diagnosis?

The clinical expression is dominated by pain in 85 % of the patients and often is associated with swelling (in more than 60 % of the cases). The pelvis and ribs are commonly affected and the tumor infiltration of the soft parts can be very large and sometimes compressing the adjacent structures. Fever is observed in almost one third of cases. Exceptionally, the disease is manifested by paraplegia due to epidural extension more than vertebral involvement.

This expansion of the tumor represents an oncological emergency and the decompression is obtained through surgical intervention in most cases (if diagnosed and intervened within 48–72 h). Ewing sarcoma usually is a chemo-and radiosensitive malignancy, and immediate initiation of chemotherapy and emergency radiation therapy are also valid alternatives in case of acute spinal compression when surgery is not an option.