A rare case of myelolipoma compressing a second-transplanted kidney: A case report and review of the literature

Introduction and importance: Myelolipoma is a rare benign neoplasm composed of mature elements of fatty and hematopoietic tissues. In addition to its low incidence, myelolipoma in kidney transplant patients is much rarer, with only a few cases of this entity reported in the literature.Case presentation: A 37-year-old diabetic patient was admitted to the hospital due to severe left abdominal pain and elevated creatinine levels of 4.4 mg/dl. The patient has a history of two kidney transplantations. The patient was investigated with different modalities of imaging, which revealed a mass adjacent to the renal graft that was suspicious for malignancy. Histopathological assessment of the resected lesion showed findings consistent with myelolipoma.Clinical discussion: Although it's uncommon, myelolipoma should be considered in the differential diagnosis of any renal or extra-renal lesion in kidney transplant patients, including those with a history of graft rejection as in our patient.Conclusion: In light of the rarity of the lesions, we affirm the significance of the clinicians' reporting such cases that they encounter in order to better understand the disease's biological behavior.