Calcific tendinitis of the rotator cuff tendons is a common cause of shoulder pain in adults and typically presents as activity-related shoulder pain. It is thought to be an active, cell-mediated process, although the exact pathophysiology remains unclear. Nonsurgical management continues to be the mainstay of treatment; most patients improve with modalities such as oral anti-inflammatory medication, physical therapy, and corticosteroid injections. Several options are available for patients who fail nonsurgical treatment, including extracorporeal shock wave therapy, ultrasound-guided needle lavage, and surgical débridement. These modalities alleviate pain by eliminating the calcific deposit, and several recent studies have demonstrated success with the use of these treatment options. Surgical management options include arthroscopic procedures to remove calcific deposits and subacromial decompression; however, the role of subacromial decompression and repair of rotator cuff defects created by removing these deposits remains controversial.
ALK is the most commonly mutated oncogene in neuroblastoma with increased mutation frequency reported at relapse. Here we report the loss of an ALK mutation in two patients at relapse and a paired neuroblastoma cell line at relapse. ALK detection methods including Sanger sequencing, targeted next-generation sequencing and a new ALK Agena MassARRAY technique were used to detect common hotspot ALK variants in tumors at diagnosis and relapse from two high-risk neuroblastoma patients. Copy number analysis including single nucleotide polymorphism array and array comparative genomic hybridization confirmed adequate tumor cell content in DNA used for mutation testing. Case 1 presented with an ALK F1174L mutation at diagnosis with a variant allele frequency (VAF) ranging between 23.5% and 28.5%, but the mutation was undetectable at relapse. Case 2 presented with an ALK R1257Q mutation at diagnosis (VAF = 39%-47.4%) which decreased to <0.01% at relapse. Segmental chromosomal aberrations were maintained between diagnosis and relapse confirming sufficient tumor cell content for mutation detection. The diagnostic SKNBE1n cell line harbors an ALK F1174S mutation, which was lost in the relapsed SKNBE2c cell line. To our knowledge, these are the first reported cases of loss of ALK mutations at relapse in neuroblastoma in the absence of ALK inhibitor therapy, reflecting intra-tumoral spatial and temporal heterogeneity. As ALK inhibitors are increasingly used in the treatment of refractory/relapsed neuroblastoma, our
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