A 19-year-old male patient was admitted to the Nephrology Department of Ankara University Faculty of Medicine due to painless hematuria, bilateral renal masses, and acute kidney injury for further investigations. He was first evaluated at another center for hematuria. There was one episode of hematuria, which had subsided spontaneously. Abdominal ultrasonography had revealed bilateral diffuse renal masses and the patient was referred to our center for further examination.\nOn admission, there was no history of fever, weight loss, night ssweats and any other health problem. The patient’s physical examination findings were unremarkable. In particular, there was no peripheral lymphadenopathy or hepatosplenomegaly. Also the kidneys were not palpable. Laboratory tests revealed white blood cell count of 7.7x109/L, hemoglobin of 11.6 g/dL, platelet count of 315x109/L, serum blood urea nitrogen of 17 mg/dL, serum creatinine of 1.5 mg/dL (normal range: 0.5-0.9), serum uric acid of 7.6 mg/dL (normal range: 2.4-5.7), serum lactate dehydrogenase of 1042 U/L (normal range: 125-220), and serum ferritin of 749 ng/mL (normal range: 11-307). Erythrocyte sedimentation rate was 52 mm/h and C-reactive protein level was 27.5 mg/L (normal: <3). Urinalysis showed density of 1010, pH of 5.5, protein of 15 mg/dL, and glucose negative, and urine microscopy showed 4 leukocytes and 3 erythrocytes per high-power field. Viral serology tests were negative. C3 and C4 as well as quantitative immunoglobulin levels were all within normal limits with negative antinuclear antibody and anti-neutrophil cytoplasmic antibody tests. Urinary ultrasonography demonstrated bilaterally enlarged kidneys without obstruction (right: 16x8 cm, left: 15.5x8 cm) and numerous solid hypoechoic nodular cortical masses in both kidneys (largest of 6.5x5.5 cm in size, numerous variably sized masses) with perirenal and paraaortic multiple enlarged lymph nodes (largest <2.5 cm in size).\nContrast-enhanced computerized tomography (CT) scanning of the abdomen confirmed bilaterally enlarged kidneys, bilateral variably sized multiple hypodense renal masses, and paraaortic, paracaval multiple enlarged lymph nodes (). In addition, the liver was slightly enlarged with normal parenchyma while the size of the spleen and parenchyma was normal.\nThereafter, 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) was performed for staging and its role in the differential diagnosis. It was performed to examine the entire body, revealing an abnormal accumulation in the thyroid gland, anterior mediastinum, bilateral hilar, right parasternal lymph node, left subdiaphragmatic lymph node, bilateral renal cortices, and multiple abdominal paraaortic, paracaval, and aortocaval lymph nodes ( and ).\nA percutaneous tru-cut biopsy of the kidney was performed and histopathological examination showed extensive infiltration of the renal parenchyma by atypical lymphoid cells ( and ). Immunohistochemical studies demonstrated positive staining of the neoplastic cells for CD20, CD10, bcl-6 (, , , and ) and negative results for MUM1 () and Bcl-2. The ki-67 proliferation index of neoplastic cells was 80% (). EBER in situ hybridization was negative. A diagnosis of diffuse large B-cell non-Hodgkin lymphoma (NHL) was made. To exclude lymphoma involvement of the bone marrow, the patient underwent bone marrow biopsy and there was not bone marrow infiltration.\nSubsequently, the patient was transferred to the department of hematology for treatment and chemotherapy regimen as well; cyclophosphamide, adriamycin, vincristine, prednisolone, and rituximab (CHOP+R) were started. After a cycle of chemotherapy, the patient’s renal functions returned to normal.
A 50-year-old female with a past medical history significant for idiopathic thrombocytopenic purpura (ITP) presented with chief complaint of back pain for three weeks. Prior to her presentation, the patient was undergoing treatment for ITP wherein she had received four doses of weekly rituximab and recently completed a prednisone taper. A computed tomography (CT) scan of the abdomen and pelvis showed bilateral renal masses (6.6 x 4.2 cm on the right, 6.3 x 5 cm on the left) with upper para-aortic and right retro-crural lymphadenopathy (Figure ). Upon chart review, it was noted that the abdominal ultrasound done seven months prior to admission (for thrombocytopenia workup) was negative for renal masses. She was admitted for evaluation; laboratory workup showed white blood cell count 10.55 TH/uL, hemoglobin 12.3 g/dL, and platelet count 113 TH/uL. Her kidney function and liver function tests were normal. Lactate dehydrogenase was elevated at 763 IU/L (range 313-618). A CT guided biopsy of the left renal mass showed DLBL (Epstein-Barr virus (EBV) negative, fluorescent in situ hybridization (FISH) negative for MYC rearrangement, but 71% of interphase cells showed three copies of an intact MYC (8q24.1), 65% positive for rearrangement of BCL6, no BCL2 fusion). Bone marrow biopsy and flow cytometry were negative. Positron emission tomography (PET)/CT showed left supraclavicular and retroperitoneal lymphadenopathy (standardized uptake values (SUV) 10.8 and 15.7 respectively) with hypermetabolic bilateral renal masses (SUV 15.3 and 17.5 on right and left respectively) (Figure ). Lumbar puncture cytology was negative. Given these findings, she was staged IVB and received intrathecal methotrexate for central nervous system (CNS) disease prevention. The next day, the patient was started on dose-adjusted rituximab, etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin (DA-REPOCH) chemotherapy regimen. She completed six cycles of DA-REPOCH and intrathecal methotrexate with no evidence of disease on repeat imaging (Figure ). She continues to follow up with oncology clinic for observation and is in complete remission at one year.