Presentation
Acute renal failure.
Patient Data
CT stone protocol:
Minute amount of pericardial effusion. Pericardial nodule adjacent to left ventricular apex.
Massive retroperitoneal lymphadenopathy.
The kidneys are enlarged due to their engulfment and infiltration by soft tissue masses to the extent that even some of the renal cortical cysts in both kidneys are partially engulfed.
Soft tissue mass infiltrating the sacrum on the left, insinuating within the left sacroiliac joint, involving the ipsilateral erector spinae muscle and obliterating the ipsilateral S1-S2 foramen.
Large ovoid heterogeneous splenic lesion with numerous punctate calcifications - features are most compatible with cavernous hemangioma.
Many diverticula along the descending and sigmoid colon.
Biopsy from the left renal mass under ultrasound guidance.
The right kidney is entirely infiltrated by the mass.
Part of the left kidney shows some semblance of normal renal architecture.
Case Discussion
Histopathology:
Kidney: (left/ tru-cut biopsy)
Macroscopic description: 3 white cylinders of tissue 1-1.5 cm long, marked with hematoxylin.Microscopic description:
Diffuse large B cell lymphoma. Normal tissue is not seen; the tissue is replaced by a sheet of large atypical cells. The atypical cells are positive for CD20, CD45, CD79a, Bcl6, Bcl2, and MUM1, and are negative for CD3, CD5, CD10, CD15, CD21, CD23, CD30, cyclin-D1 and c-Myc (~20%). Ki67 is positive in approximately 75-80% of the cells.
Radiologically overt renal involvement in diffuse large B cell lymphoma is uncommon, let alone masses that engulf much of the kidneys, as in this case.