32-year-old male presents with left flank pain ,swelling of legs, backache. Routine blood investigations showed raised creatinine of 1.54 mg/dl. Ultrasound abdomen taken showed soft tissue encasing aorta with right kidney smaller in size and both  kidney having hydroureteronephrosis. He underwent DJ stenting of left ureter. Contrast enhanced CT abdomen(Figure 1) showed homogenous soft tissue density lesion in retroperitoneal compartment encasing Aorta, Inferior Vena Cava(IVC), proximal common iliac vessels and both ureters consistent with Retroperitoneal Fibrosis(RPF). Since the biopsy of retroperitoneal mass was not feasible, it was deferred. Causes for Retroperitoneal tissue include Immunoglobin G4 related disease (IGG4RD) induced RPF, lymphoma, Idiopathic Retroperitoneal fibrosis, Erdheim Chester disease. His Igg4 levels were in normal range. He was given trial of steroids elsewhere with no improvement in symptoms or resolution of soft tissue around the vessels. He didn’t have any organ involvement suggestive of IGG4RD like salivary, ophthalmic, pancreatic or interstitial nephritis. His Igg4 levels were also in normal levels. Hence he was diagnosed as a case of Idiopathic RPF.It is usually located distal to the kidney hilum and anteriorly or laterally to the aorta, which is usually not displaced forward whereas Lymphoma can dislocate the aorta anteriorly or reach up to the mediastinum. Medial displacement of the ureter  is common with RPF when compared to lymphoma. Maiden Waist Sign -Medial deviation and tapering of both ureter at lumbosacral junction is a radiological sign observed in RPF due to encasing of ureters by the fibrous tissue.Hence, he was diagnosed as Idiopathic Retroperitoneal Fibrosis.

Coronal view of Contrast enhanced CT Abdomen(Figure 1) : Red Arrows showing soft tissue encasing Aorta & IVC, Blue Arrows showing Medialization of left ureter as shown by the  stent in situ.

Coronal view of Contrast enhanced CT Abdomen Fig 2 Right kidney atrophy with cortical scarring and hydroureteronephrosis, Left kidney has prominent renal pelvis

CASE 2

32 Year old female presented with painless swelling over lateral aspect of inner canthus of both eyes and sicca symptoms.Examination showed bilateral dacryoadenitis and cervical lymphadenoapathy.IGG4D ,Lymphoma,Sjogrens syndrome & Sarcoidosis were the differentials for bilateral lacrimal gland enlargement. Cervical lymph node biopsy  showed  non caseating granulomas changes suggesive of Sarcoidosis.Her serum ACE levels value being 120 IU/l(nl- 55 IU/l).

 

Reference:

1 Zhang S, Chen M, Li CM, Song GD, Liu Y. Differentiation of Lymphoma Presenting as Retroperitoneal Mass and Retroperitoneal Fibrosis: Evaluation with Multidetector-row Computed Tomography. Chin Med J (Engl). 2017 Mar.

2 Bansal, S., Gupta, S. Maiden Waist Deformity in a Case of Bilateral Idiopathic Retroperitoneal Fibrosis. Indian J Surg 83, 366–367

Bilateral dacryoadenitis as an initial manifestation of sarcoidosis head and neck imaging /eurorad/case.19369