Unusual Presentation of Painless Hematuria Uncovers Diagnosis of Primary Pediatric Stage III Renal B-Cell Lymphoblastic Lymphoma
2026 Research Day Corewell Health West, Grand Rapids, MI, May 8, 2026. Abstract 1679
Abstract
Primary renal lymphoma is exceptionally rare, presenting as approximately 1% of all lymphomas and 2% of renal malignancies; as few as 20 pediatric cases have been reported since 1995. Diagnosis in the pediatric population is especially challenging due to non-specific presentation characteristics, such as fatigue, weight loss, abdominal pain, hematuria, and renal failure. Primary renal lymphoma radiologic findings can also mimic other more common renal pathologies, including renal cell carcinoma (RCC), clear cell sarcoma, and Wilm's tumor. Early diagnosis is critical as this malignancy can be more aggressive in the pediatric population. This case report is intended to expand upon the limited known presentations and knowledge available concerning primary renal lymphoma to broaden provider differentials and enable earlier intervention.
The patient is a 15-year-old female with no significant past medical history who presented from an outside hospital with the sole complaint of a two-day history of painless hematuria. Lab workup was significant for blood on urinalysis and elevated creatinine (0.96) as well as decreased iron saturation percentage (11%), ferritin (5), hemoglobin (8.7), hematocrit (29.5), and mean corpuscular volume (70.1). Bilateral renal ultrasound and CT Abdomen Pelvis with IV contrast demonstrated two solid mass-like lesions in the interpolar region and lower pole of the right kidney without evidence of adenopathy. Following discussion with hematology/oncology and radiology, the differential included RCC, clear cell sarcoma, Wilm's tumor, lymphoma, and other less common malignancies. Wilm's tumors and clear cell sarcomas are capable of multi-lobular presentations; however, these malignancies are typically diagnosed within years 2 to 5. Therefore, RCC was the most likely diagnosis.
Due to the rare occurrence and non-specific presentation with varying severity of primary renal lymphoma, it can be easily missed or misdiagnosed. In this case, diagnosis was complicated by a singular presenting symptom of hematuria, anemia, and non-specific imaging findings consistent with renal malignancy of unknown origin. With cases of unusual renal malignancy in adult and pediatric patients, it is critical to remain vigilant in maintaining broad differential diagnoses, including rare presentations of renal lymphoma, to ensure timely intervention and treatment.