Characteristics of Renal Cell Carcinoma Harboring TPM3-ALK Fusion

The World Health Organization 2016 edition assigned anaplastic lymphoma kinase (ALK) rearrangement-associated renal cell carcinoma (ALK-RCC) as an emerging renal tumor entity. Identifying ALK-RCC is important because ALK inhibitors have been shown to be effective in treatment. Here, we report the case of a 14-year-old young man with ALK-RCC. Computed tomography revealed a well-demarcated 5.3-cm enhancing mass at the upper pole of the left kidney. There was no further history or symptoms of the sickle-cell trait. The patient underwent left radical nephrectomy. Pathologically, the mass was diagnosed as an unclassified RCC. Targeted next-generation sequencing identified a TPM3-ALK fusion gene. The present report and literature review demonstrate that TPM3-ALK RCC may be associated with distinct clinicopathological features. Microscopically, the tumors showed diffuse growth and tubulocystic changes with inflammatory cell infiltration. Tumor cells were dis-cohesive and epithelioid with abundant eosinophilic cytoplasm and cytoplasmic vacuoles. If morphological features and TFE3 expression are present in adolescent and young patients, molecular tests for ALK translocation should be performed. This awareness is critically important, because ALK rearrangement confers sensitivity to ALK inhibitors.

A Family of Congenital Fiber Type Disproportion with Mutation in Tropomyosin 3 (TPM3) Gene Presenting as Altered Mentality with Respiratory Distress

Congenital fiber type disproportion (CFTD) has been related with mutations in ACTA1, SEPN1, RYR1 and tropomyosin 3 (TPM3) genes. Particularly, TPM3 mutation was identified as one of the most frequent cause of CFTD and was also detected in cap myopathy and nemaline myopathy. Herein we report patients of autosomal dominant TPM3 missense mutations with CFTD in a Korean family over twogenerations. Two of our patients, who developed mild muscle weakness in infancy, presented with altered mentality and respiratory distress despite relatively mild limb weakness.