LAUSR

Rationale: Thyroid carcinoma-like tumor of the kidney (TLFCK) is an extremely rare variant of renal cell carcinoma. Most cases were incidentally found, while we report the first case of TLFCK presented with hypertension. Patient concerns: A 25-year-old woman was admitted to our hospital presenting with hypertension for ∼20 months, without gross hematuria, weight loss, and flank pain. Diagnoses: Imaging studies revealed a right renal mass with multiple calcifications. Histologically, the tumor had striking follicles with dense, colloid-like material resembling thyroid follicular carcinoma while the tumor cells were negative for thyroid markers (thyroglobulin and thyroid transcription factor-1). Interventions: The patient successfully underwent nephron sparing surgery with an uneventful recovery. Outcomes: Hypertension returned to normal without any medication interference. Two years after surgery, the patient is still in good health without recurring disease or related hypertension. Lessons: Recognition of the cytomorphological features of TLFCK can avoid misdiagnosis of this renal tumor as a metastatic carcinoma and the objective of surgical management is to remove the tumor and preserve renal function.