Renal lymphoma

Clinical History

A 71-year-old female patient, with hypertension and oesophageal hiatus hernia, is admitted to the ER with a febrile syndrome of unknown origin.

Imaging Findings

Ultrasound was performed, defining the presence of multiple hypoechoic nodules (Fig. 1). CT shows multiple hypodense and low contrast enhancement lesions (Fig. 2). The findings on MR are overlapping (Fig. 3).

Surgical biopsy is performed and the histological result was: high-grade mitotic centroblastic B-cell lymphoma (CD20, CD10).

The patient starts chemotherapy, with complete remission.

Discussion

BACKGROUND: Isolated renal lymphoma is rare, since the kidney lacks lymphoid tissue.
Secondary involvement is more frequent, occurring in up to one third of autopsies of patients with lymphoma. Some authors believe that this is the only form of renal involvement, questioning the existence of primary lymphoma. Kidney lymphoma would represent haematogenous metastases or direct invasion of the tumour, resulting in different types of renal lymphoma presentation: multiple nodules (the most frequent), solitary mass, renal invasion from contiguous retroperitoneal disease, peri-renal disease and diffuse infiltration.

CLINICAL PERSPECTIVE: Non-Hodgkin lymphoma is the most frequent type with renal involvement. Symptoms are vague and usually present in advanced stages of the disease – pain; haematuria, hypertension, renal vein thrombosis, obstructive uropathy.

IMAGING PERSPECTIVE: US - Usually, the first detection exam of renal mass - hypoechogenic; Doppler - reduced vascularization of the mass; echo-guided biopsy (preferred, does not involve radiation; real-time manipulation). CT - Definition of renal lesions and extension to adjacent anatomical structures; usually hypodense lesions; CT guided biopsy. MR - Sensitivity and specificity equal to CT; useful if iodinated contrast is contraindicated; hypointense signal on T1; hypo/iso-signal on T2.

PET-CT - It will take major role as a routine technique for evidence of metabolic activity/anatomical detail, with the possibility of earlier detection.

OUTCOME: Depending on histological type; therapeutic options are limited to chemotherapy.

TAKE HOME MESSAGE: Clinically asymptomatic until advanced stages; multiple differential diagnoses; biopsy is usually required.

Differential Diagnosis List

Final Diagnosis

Renal lymphoma

URL:	https://eurorad.org/case/10225
DOI:	10.1594/EURORAD/CASE.10225
ISSN:	1563-4086