[Pseudo-Perthes' disease caused by acute lymphatic leukemia]

Area of Science:

• Pediatric Oncology
• Pediatric Orthopedics
• Hematology

Background:

• Legg-Calvé-Perthes disease is a hip condition affecting children, characterized by avascular necrosis of the femoral head.
• Acute lymphoblastic leukemia (ALL) can present with bone involvement, sometimes mimicking other orthopedic conditions.
• Early diagnosis and treatment are crucial for both Legg-Calvé-Perthes disease and ALL.

Observation:

• A two-year-old boy presented with symptoms suggestive of Legg-Calvé-Perthes disease.
• Initial scintigraphy revealed decreased nuclear activity in the femoral head, consistent with early Legg-Calvé-Perthes disease.
• A subsequent blood count led to the diagnosis of acute lymphoblastic leukemia (ALL).

Findings:

• The patient received multiagent chemotherapy for ALL according to the Austrian cooperative leukemia protocol, achieving complete remission.
• No specific orthopedic treatment for the femoral head necrosis was administered.
• Within eight weeks of chemotherapy, the child regained the ability to walk, and Legg-Calvé-Perthes disease symptoms resolved. Follow-up scintigraphy showed near-complete resolution of the femoral head's reduced radionuclear activity.

Implications:

• This case underscores the potential for bone manifestations, such as Legg-Calvé-Perthes disease-like symptoms, to be the primary presenting sign of acute lymphoblastic leukemia in children.
• It suggests that effective chemotherapy for ALL may lead to the resolution of associated bone abnormalities, including avascular necrosis of the femoral head.
• The findings emphasize the importance of a comprehensive diagnostic approach when children present with orthopedic symptoms that could potentially mask or be related to underlying hematological malignancies.