Spontaneous rupture of renal pelvis (SRRP) is a rare condition resulting in an extravasation of urine into retroperitoneal space. Due to the uncharacteristic symptoms, often mimicking renal colic, its diagnosis may be complicated. Herein, we report a case of a 73-year-old male with a solitary functioning kidney who presented with malaise and right-sided abdominal pain, rapidly followed by anuria. Laboratory tests showed the signs of AKI. Contrast-enhanced CT performed soon after the admission showed nonspecific abnormalities in the right middle abdomen suspected to be either inflammatory infiltration or surgical scarring. Symptomatic treatment was started, and an acute hemodialysis treatment was commenced. After a temporal improvement, the patient’s general condition worsened significantly, with exacerbated pain and massive increase in plasma creatinine. A second contrast-enhanced CT was performed with an addition of urography phase, revealing the extravasation of the contrast media in the location suggesting the rupture of the renal pelvis. The patient was treated successfully by the placement of a double-J ureteral stent into the ureter. Usually, a clear etiology of SRRP can be determined, that is, urinary tract obstruction, but in this case, we could not find a definite cause. It is important to remember that in the presence of a nonspecific abdominal pain and laboratory signs of AKI, a rare cause like SRRP should be taken into consideration. Performing a contrast CT scan with urography phase can save time in establishing a diagnosis and enable immediate urological intervention.

Hemophagocytic lymphohistiocytosis (HLH) is an uncommon life-threatening condition caused by an uncontrolled immunological response. It can develop secondary to malignancies, infections, systemic diseases, and immunosuppression. Multiple risk factors may present in kidney transplant recipients; however, the cases of HLH in this population have been described sparsely. We report a case of a 39-year-old female kidney transplant recipient who presented to the hospital nearly 3.5 years after the transplantation with general malaise, recent history of weight loss, fevers, and persistent anemia. Laboratory tests showed pancytopenia, hyperferritinemia, hypertriglyceridemia, and increased activity of lactate dehydrogenase. A bone marrow aspiration revealed hemophagocytosis, which led to the diagnosis of HLH. Therapy consisting of high-dose steroids and plasma exchanges was administered, resulting in a significant improvement of blood count parameters and the patient’s general condition. While searching for the triggering disease, a single cavitary lesion in the right lung was revealed in a chest radiograph. Computed tomography scan, bronchoscopy, and additional laboratory testing did not reveal a definitive cause of the lesion. We suspect that the lesion may be a consequence of HLH. The patient was disqualified from thoracic surgery due to multiple comorbidities. Even though HLH is a rare condition, it should be taken into consideration in a kidney transplant patient presenting with unspecific symptoms accompanied by a bicytopenia. It has an unpredictable course that often results in serious complications. Thus close follow-up of the patient and a wide array of imaging and laboratory tests remain crucial.