ALK-TPM3 rearrangement in adult renal cell carcinoma: a case report and literature review

Background Translocation-associated renal cell carcinoma involving ALK (ALK-tRCC) is a rare subtype of adult renal cell carcinoma (RCC) reported in recent years. It was recognized as a group of emerging /provisional RCC in the latest World Health Organization's classification (2016). Case presentation A new Chinese case of ALK-tRCC was reported. The patient was a 58-year-old man with a tumor in kidney. The tumor was composed of sheets of large cells with abundant eosinophilic cytoplasm and indistinct cell borders but conspicuous intracytoplasmic vacuoles. The nuclei were enlarged with a nucleolar of grade 4. Immunohistochemically, tumor cells were diffusely positive for PAX8, keratin (AE1/AE3), epithelial membrane antigen (EMA) and CK7. Fluorescent in situ hybridization (FISH) showed a rearrangement of ALK in tumor cells. Conclusion ALK-tRCC is a rare subtype of adult RCC. Its diagnosis is very difficult because the histological spectrum is very wide. We suggested that RCCs should be screened for ALK expression by immunohistochemistry (IHC) for the patient might benefit from ALK inhibitors therapy.