ALK-positive anaplastic large cell lymphoma with multifocal bone involvements: a case report and review of the literature

Anaplastic large cell lymphoma (ALCL) is a rare disease characterized by the infiltration of pleomorphic cells and expression of Ki-1 or CD30 antigen. ALCL, usually involves with lymph nodes, also with skin, liver, lung, soft tissue, and bone marrow, but bone involvement is rare. We reported a 16-year-old boy presented with an eight-month history of pain in his dorsal spine and with late one-month history of ache in his left articulatio coxae accompanied with the limitation of motion. CT and MRI scans reported the bone destruction in the left iliac bone, thoracic vertebra 11, 12, lumbar vertebra 1-4, and sacral vertebra. A seriously squeezed 1st lumbar vertebra was also observed. By the second biopsy of left iliac bone, ALK (anaplastic lymphoma kinase) positive ALCL was diagnosed. The patient responded well to the DHAP chemotherapy. In conclusions, ALCL can present with multiple or solitary bone involvement, meticulous examination of initial and repetitive biopsy is recommended to make an accurate diagnosis of ALCL. Suitable chemotherapy should be adopted after diagnosis.