Myelolipoma of renal sinus in a patient with end-stage renal disease: A rare differential diagnosis in renal neoplasms

Myelolipoma is an uncommon benign neoplasm composed of mature adipose tissue and hematopoietic elements. Myelolipoma occurs most frequently in the adrenal gland but occasionally can be seen in extra-adrenal locations such as lung, liver, retroperitoneum, mediastinum, and kidney. We report a case of extra-adrenal myelolipoma presented as a localized asymptomatic mass in the renal sinus of left native kidney of a 60-year-old woman. The patient was being investigated for end-stage renal disease status post renal transplant. Histologic examination of the lesion showed classic features for myelolipoma. Our case illustrates the awareness of this entity in unusual location and the appropriate use of diagnostic modalities to prevent unnecessary surgical interventions particularly in patients with major co-morbidity in the future.