Description

A 59-year-old woman visited our hospital with a 2-week history of numbness over the left buttock and lateral aspect of the left thigh in December 2011. Contrast-enhanced CT showed a retroperitoneal mass anterior to the left wing of the ileum, infiltrating the left sacral foramen. Contrast-enhanced CT showed bilateral soft-tissue renal masses partially deforming the contours of the kidneys (figure 1). Increased uptake in these masses was evident on positron emission tomography (PET)-CT (figure 1). Diffuse large B-cell lymphoma (DLBCL) was diagnosed from CT-guided percutaneous needle biopsy of the retroperitoneal mass. The patient was staged as IVA, and treated with six cycles of rituximab–cyclophosphamide–doxorubicine–vincristine–prednisolone therapy. Complete remission was achieved after therapy.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1

Contrast-enhanced CT showed a retroperitoneal mass anterior to the left wing of the ileum, infiltrating the left sacral foramen, and also showed bilateral soft-tissue renal masses partially deforming the contours of the kidneys. Increased uptake in these masses was evident on positron emission tomography-CT.

Renal involvement appears uncommon in DLBCL, although some reports from autopsy series of lymphoma patients have suggested that renal involvement may actually be relatively common.1 This may be because renal lymphoma is clinically silent and radiological findings are missing. Recently, patients with DLBCL and kidney involvement at diagnosis have shown poor prognosis, due in part to the high incidence of central nervous system relapse.2 Although fluorodeoxyglucose is excreted renally and increased uptake in the kidneys is usually related to this, PET-CT combined with CT could help determine DLBCL involvement.