A 50-year-old Caucasian male with a history of alcohol and injection-drug abuse, chronic HCV infection, coronary heart disease, and idiopathic renal function impairment (creatinine clearance < 60 mL/min) for preceding four months attended in the emergency department with uremic symptomatology. He was dysphonic (O2 saturation, 85%) and hypertensive (blood pressure, 185/90 mmHg) and had prominent hepatosplenomegaly with mild peripheral edema; he had no palpable lymph nodes, skin rash, or other manifestations of systemic diseases. Laboratory analyses results were as follows: metabolic acidosis (pH, 7.123; and HCO3-, 8.6 mmol/L); mild hyperkalemia (K+, 5.7 mmol/L); hyperphosphatemia (PO43-, 10 mg/dL); hypoalbuminemia (albumin, 2.8g/L); anemia (hematocrit, 21.2%; and hemoglobin, 6.8 g/dL); thrombocytopenia (platelet, 72 × 10³/μL); lactate dehydrogenase,185 U/L; and severe renal failure (serum creatinine, 9.9 mg/dL; and urea, 199 mg/dL) with signs of glomerular involvement (urine red blood cells, 40 to 60/HPF; and 24-hour urine proteins, 3.06 g).\nThe clinical and laboratory findings on admission necessitated the immediate start of hemodialysis. Subsequent ultrasound studies revealed hepatosplenomegaly, two kidneys of normal size (right kidney, 11.7 cm; and left kidney, 11.5 cm), and parenchymal thickness (right kidney, 10 mm; and left kidney, 9.9 mm). There was no clinical or radiological sign of lymph nodes involvement. Further laboratory testing by immunological assay (ANA, anti-dsDNA, ASMA, AMA, C-ANCA, P-ANCA, and C3 complement levels) had negative results except for serum proteins electrophoresis, which showed a monoclonal gammopathy of IgM. At the same time, urine immunofixation revealed the presence of albumin, IgM, and kappa light chains, type I cryoglobulinemia, and low C4 complement levels. Considering the history of the patient and after excluding and treating all other causes of renal function deterioration, our diagnostic approach pointed towards an HCV-related renal offence in the context of cryoglobulinemia. However, the rapid decline of renal function and the absence of mixed cryoglobulinemia suggested performing the renal biopsy. While the histopathological examination of the specimen was consistent with the initial suspicion, indicating MPGN (), the immunofluorescence study revealed two unusual findings: dominant monoclonal IgMκ deposits in glomerular basement membrane and infiltration of the interstitium by abundant strongly IgM-positive lymphoid cells (). The presence of CD20 cell marker was distinctive while CD5 was absent. According to these findings, a bone marrow biopsy was performed. The histopathological examination revealed plasmacytic differentiation of small B cells and the immunophenotyping results were positive for CD20 and negative for CD5. These findings were consistent with SMZL. The patient became hemodialysis dependent and received no treatment for the lymphoproliferative disease and was monitored regularly for possible transformation to a high-differentiated lymphoma.
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.