Massive bone marrow necrosis associated with Waldenström’s macroglobulinemia

Here, we report a rare case of massive bone marrow necrosis, which – from the clinical findings and images – mimics disseminated bone metastasis. The patient was suffering from severe bone pain with elevated levels of serum alkaline phosphatase (ALP) and lactate dehydrogenase (LDH); moreover, strong incorporation of 18F-fluorodeoxyglucose in multiple bones was observed by positron emission tomography/computed tomography.The underlying disease was Waldenström’s macroglobulinemia, which was thought to transform to cluster of differentiation 5 (CD5)-positive diffuse large B-cell lymphoma (DLBCL). The case showed a highly aggressive course, although the original Waldenström’s macroglobulinemia was in the stable state.Clinicians should be aware of the co-occurrence of non-immunoglobulin-producing immature lymphoma, even with good course of Waldenström’s macroglobulinemia, and should pay attention to accompanying massive bone marrow necrosis, which mimics multiple cancer metastases to the bone. To the best of our knowledge, the present case is the first report of CD5-positive DLBCL transformed from CD5-negative Waldenström’s macroglobulinemia

Persistent Hemarthrosis of the Knee after Arthroscopic Meniscal Repair

Introduction. In this case report, we report a patient with complicated with persistent hemarthrosis following arthroscopic meniscal repair. Case Presentation. A 41-year-old male patient presented with persistent swelling of the knee 6 months after arthroscopic meniscal repair and partial meniscectomy performed for lateral discoid meniscal tear. The initial surgery was performed at another hospital. Four months after the surgery, swelling of the knee was noted when he resumed running. At his initial visit to our hospital, intra-articular blood accumulation was revealed via joint aspiration. A second arthroscopic examination performed 7 months after the initial procedure showed healing of the meniscal repair site and synovial proliferation. The suture materials identified during the arthroscopy were removed. Histological examination of the resected synovial tissue showed inflammatory cell infiltration and neovascularization. In addition, a multinucleated giant cell was identified in the superficial layer. After the second arthroscopic surgery, the hemarthrosis did not recur, and the patient was able to resume running without symptom one and a half years post-surgery. Conclusion. Bleeding from the proliferated synovia at or near the periphery of the lateral meniscus was thought to be the cause of the hemarthrosis as a rare complication following arthroscopic meniscal repair