Thirty six-year-old male was presented with left tibial mass for the last 6 months. MRI showed contour irregularity and cortical thinning at the diaphysis of the left tibia and 1.5 cm severe periostal reaction at the same region. On follow-up, pathologic fracture of the left tibia occured. The intramedullary and soft tissue curettage of the left tibia, performed 3 months after the fracture, confirmed high grade diffuse large B-cell lymphoma. There is no past medical and genitourinary history. Laboratory analysis showed a normal complete blood count, normal urine analysis, and normal basic metabolic panel. Patient was reffered to our PET/CT unit for initial staging. FDG PET/CT scan showed a very intense FDG accumulation (SUVmax: 17.1) at the distal 2/3 of the left tibia extending to neighbouring soft tissue and proximal metaphysis of the left tibia which were compatible with primary disease involvement. Additionally, there was diffuse highly intense FDG uptake in the bilateral hyperplastic kidneys which was consistent with disease involvement (). The possibility of nephrotoxicity was excluded because of normal laboratory examination and no drug history.\nPatient underwent local external radiotherapy to the left tibia and systemic chemotherapy. Four months after the treatment, repeated FDG PET/CT scan revealed complete resolution of the renal lesions, indicative of complete remission. There was near-complete remission in the left tibia lesion. Middle part of left the tibial diaphysis which showed slightly increased FDG uptake in the fracture line was considered as an inflammatory process ().\nLiterature Review and Discussion\nNon-hodgkin lymphomas (NHL) are grouped as nodal and extranodal lymphoma according to their localization. Extranodal localization exists in 25%-40% of all NHL cases and can occur in any organ including gastrointestinal tract, head-neck, orbita, central nervous system, lungs, bones, breast, testis, thyroid and genitourinary system (). It may be multifocal involving two or more organs ().\nThe incidence of secondary renal involvement is about 3% (). Primary renal lymphoma (PRL) is even more uncommon, accounting for less than 1% of all lymphomas. PRL can occur as a solitary renal nodule or as an infiltrative renal disease. The most common presentation of PRL is acute renal failure, proteinuria, microscopic hematuria and renal enlargement. The prognosis of PRL is usually poor (). Early diagnosis is important for preserving renal function.\nPrimary lymphoma of bone is also a rare disease that represents less than 1% of all lymphomas, 5% of extranodal NHL and 3%-5% of all primary bone tumours (). NHL usually shows solitary bone involvement and mostly involves diametaphysis of long bones (). The most common manifestation of primary NHL of bone is frequent pathological fracture (). There are multiple imaging features of primary bone NHL, including a near-normal bone appearance, focal lytic lesion with geographic margins or a diffusely permeative lesion with bone destruction and soft-tissue involvement (). Although CT scan can discriminate trabecular destruction, periosteal reaction, sequestration and extraosseos lesions in patients with bone involvement, it may not differentiate malign and benign bone tumours. In such cases, more advanced imaging techniques such as magnetic resonance imaging (MRI) and FDG PET/CT imaging are required for diagnosis (). On the basis of follow-up of patients, the differential diagnosis of persistent lymphoma from healing bone may not be reliably done by MRI but PET/CT imaging has superiority in assessing remission status (). Shin DS et al. reported that there was low FDG uptake within cortical bone or adjacent soft tissue around the fracture in benign fracture, rarely in the marrow. The patternof intramedullary FDG uptake between malignant and benign fractures were significantly different. The sensitivity, specificity and diagnostic accuracy of F-18 FDG PET/CT were 89.5%, 86.7% and 88.2%, respectively, with a cut-off SUVmax set at 4.7. The time interval between fracture and PET/CT did not significantly influence FDG uptake at the fracture site (). It has been reported that FDG PET/CT is a superior imaging modality to demonstrate early lymphoma involvement of bones (). However, FDG PET/CT has some limitations especially in evaluation of minimally residual disease and therapy response in patients with diffuse bone marrow uptake because of growth stimulating factor (GSF) usage ().\nWe report an unusual case of extranodal lymphoma of bone and kidneys shown by FDG PET/CT scan. The simultaneous tibia and bilateral renal involvement is rarely seen in lymphoma. This case illustrates the imaging findings of the extranodal DLBCL of kidney and bones and benefits of FDG PET/CT imaging in evaluating the extent of disease and assessing the treatment response in lymphoma.\nConflicts of Interest\nThere are no conflicts of interest.
A 75-year-old man with stage IV CKD on a background of previously poorly controlled type 2 diabetes mellitus (T2DM) was reviewed in his routine renal outpatient appointment. His renal function had been slowly worsening for the past 2 years; however, on this occasion a marked increase in creatinine and proteinuria was noted despite excellent blood glucose control during the preceding 6 months, with an average glycated haemoglobin (HbA1c) of 5% ().\nApart from the T2DM complicated by neuropathy and nephropathy, his past medical history also included hypertension.\nHe was compliant with all of his medications with no significant recent medication changes and his regular medications included gliclazide, moxonidine, telmisartan/amlodipine, oral iron sulfate and vadadustat (an oral prolyl hydroxylase inhibitor).\nHe was an ex-smoker having smoked during his teenage years and he consumed less than 3 units of alcohol/week.\nThere was no family history of renal disease or haematological malignancies.\nExamination revealed moderate lymphadenopathy in the left cervical region. There was no other peripheral lymphadenopathy and no hepatosplenomegaly. The remainder of the examination was normal.\nPlans for renal replacement therapy were made, including commencement of work-up to determine suitability for renal transplantation and to investigate the lymphadenopathy. A subsequent CT of his abdomen revealed extensive lymphadenopathy. Due to progressive fluid overload and worsening biochemical parameters, he was commenced on haemodialysis.