Anaplastic lymphoma kinase-positive anaplastic large-cell lymphoma with primary bone involvement: a case report

Lymphomas originating in bone but not involving visceral or regional lymph nodes are diagnosed as primary bone lymphoma (PBL). Few case reports of anaplastic large-cell lymphoma (ALCL) originating in bone have been reported. The purpose of this report is to describe the difficulty in diagnosing and complete treatment process of this rare type of bone lymphoma.

We describe a case of anaplastic lymphoma kinase positive (ALK⁺) ALCL patient with primary multiple bone lesions. The patient was initially in the local hospital due to lumbosacral pain and was diagnosed with multiple myeloma. However, after receiving two cycles of bortezomib, lenalidomide and dexamethasone (VRD) chemotherapy, the patient's pain increased. After discussion with the patient and his family, the patient finally agreed to accept the biopsy of the T10 and L2 vertebral bodies and diagnosed as ALK⁺ ALCL stage IV with primary bone involvement. After receiving multiple cycles of chemotherapy, local bone radiotherapy and denosumab treatment, the patient's bone pain and osteolytic lesions were improved. Regular follow-up shows that the patient's bone pain has been controlled and he is generally in good condition.

ALK⁺ ALCL originating primarily in the bone may be easily misdiagnosed and hence require appropriate evaluation in the upfront setting. In consideration of the lack of relevant experience due to the rarity of the disease, choosing a suitable treatment regimen requires comprehensive consideration. In the next clinical work, we must observe relevant cases to summarize the treatment experience better.