A case report: renal cystic tumoural calcinosis with ossification and bone marrow formation

BACKGROUND: Tumoural calcinosis (TC) is a rare disorder characterized by nonneoplastic amorphous calcium deposition that tends to occur in soft tissues around the large joint. Here, we report a case of cystic TC with ossification and bone marrow formation in the kidney. CASE PRESENTATION: We report a 63-year-old woman who presented with a complaint of intermittent right lumbar pain for 2 months. Computed tomography (CT) revealed a large cystic lesion on the lateral side of the right kidney, with a circular calcified wall around the lesion, which compressed, deformed and displaced the right kidney. To relieve the symptoms of right lumbar pain, the patient underwent surgical resection of this cystic lesion without partial removal of the renal parenchyma. The pathological results further confirmed the diagnosis of cystic TC with ossification and bone marrow formation in the right kidney. No recurrence was detected 1 year after surgery. CONCLUSIONS: The main differential diagnoses of TC in the kidney are kidney stone, renal tuberculosis, renal cyst with a calcified wall, and tumour. Patients are treated mainly by complete surgical resection of the lesion.