Renal Lymphangiectasia is a very rarely seen benign usually asymptomatic condition where imaging studies can play a very important role in differentiation from other conditions. Also, it can help in determining the extension of the fluid collection and reduces the morbidity associated with it. In difficult cases, aspiration of fluid can confirm the diagnosis and can avoid the unnecessary surgical interventions with their associated complications. Awareness about this condition will result in early diagnosis, early treatment and reduced morbidity.

1. Bilateral renal lymphangiectasia :
case presentation
Dr. Arushi Bhartiya MDRD
L.L.R.M Medical college, Meerut

2. Case history
● A 24 year old male came with the complaints of non-specific vague heaviness in
flanks and occasional low grade flank pain and microscopic hematuria from 6
month.
● Ultrasound done elsewhere as a work for the same revealed bilateral perirenal
collections.The patient was then reffered to our department for further
investigations.
● He had no significant medical or family history. There was no positive history of
infection or trauma.

3. EXAMINATION
● Routine laboratory investigations revealed his haemoglobin, total leucocyte count
and differential leucocyte counts to be within normal limits. His blood urea nitrogen
level was 7.14 mmol/L (normal range: 8.0–16.4 mmol/L), serum creatinine 79.56
µmol/L (normal range: 50–110 µmol/L) and blood urea nitrogen to creatinine ratio
22.2 (normal value: < 10:1), indicating prerenal azotaemia. His urine examination
was normal.
● The patient subsequently underwent imaging to assess the abdominal pain and
distention.

4. Imaging
On USG
● US examination demonstrates large multiseptated, thin-walled fluid collections,
localised to the perinephric and peripelvic space, the renal cortex may show
scalloping secondary to cysts in perinephric space.
● The kidneys are of normal size with increased cortical echogenicity without loss of
corticomedullary differentiation.
● Mild fluid in peritoneal cavity is also present.

5. Gray scale ultrasound image of right kidney: (a) and left kidney; (b) showing multi septated
anechoic collection (asterisk) in perinephric region with increased renal cortical echotexture.

6. IMAGING
On CECT ABDOMEN
● CT examination may show the presence of low-density fluid collections (0 to 10
HU) in the perinephric space with normal renal parenchymal enhancement and
contrast excretion ,but the septations may not be delineated as clearly as in US.
There will be no invasion of the adjacent structures or evidence of cysts in other
organs. The renal cortex may show scalloping secondary to cysts in perinephric
space.

7. Cortico-medullary phase of CT scan Abdomen in coronal plane showing multi septated non-
enhancing Collection with average HU density 0 to 10 HU; (b) MPR reformation of Coronal
plane of delayed phase of CT scan abdomen showing normal excretion of contrast.

8. IMAGING
MRI
● On MRI scans, there are large multiseptated cytic perirenal lesion noted which
display hypointense signals on T1-weighted images and hyperintense on T2-
weighted images.

9. FOR CONFIRMATION OF DIAGNOSIS
● The confirmation of diagnosis is done by percutaneous fluid aspiration and cytology
of aspirated fluid.
● In our case the perinephric fluid collection aspiration and laboratory investigation
showed total leucocyte count of 55/cmm, out of which 85% were lymphocytes;
protein level of 550mg/dl, normal glucose level and increased triglycerides and no
organism was found on culture and sensitivity test, which confirmed the diagnosis.

10. DIFFERENTIAL DIAGNOSIS
Most common differential diagnosis are
● Polycystic kidneys
● Urinoma
● Hydronephrosis
Other renal cystic masses like nephroblastomatosis, lymphoma, multilocular cystic
nephroma are also included in differentials.

11. ● In polycystic kidneys, the renal cortex shows the presence of cysts distorting renal
parenchyma and causing splaying of PC system. Whereas in RLM, the renal
cortex appears normal. IN RLM, the renal cortex may show scalloping secondary
to cysts in perinephric space.
● In hydronephrosis, there is dilatation of the collecting system, whereas RLM
manifested as cystic lesions in the renal sinus often displace the otherwise normal
collecting system. On contrast-enhanced CT, there is opacification of the
collecting system on delayed scans, whereas, in RLM, there is no opacification of
cyst on delayed scans in contrast-enhanced CT.
● Urinoma most commonly occurs due to blunt or penetrating renal trauma and also
due to pelvi ureteric junction obstruction. Imaging on ultrasound and CT reveals a
localized or diffuse cystic perirenal mass. However, urinary leakage is
demonstrated on contrast-enhanced CT in the delayed phase, whereas in RLM,
there is no evidence of contrast opacification of the cystic lesions in the excretory
phase .

12. ● Multilocular cystic nephroma is a rare non-hereditary benign renal neoplasm arising from metanephric
blastema. It is characterized by a focal multiloculated cystic mass of near-water HU ± herniating into the
renal hilum. On ultrasound, it appears as a multicystic mass with no solid or nodular component. On CT, it
appears as an encapsulated well-circumscribed mass with enhancing septa and no excretion of contrast
agent into the cyst. At times, extension into the renal pelvis and ureter may also be seen. Even though
imaging appearances are similar to RLM, they can be differentiated using contrast-enhanced ultrasound
(CEUS). The enhancement pattern in the tissue between the cysts and loculi is the same as that of the
normal renal parenchyma in lymphangioma due to the concept of septations that are normal renal
parenchyma compressed between the focally enlarged lymph channels. However, in multilocular cystic
nephroma, there is a malignant CEUS pattern rather than a normal parenchymal pattern
● Renal lymphoma is characterized by multiple bilateral renal masses or perinephric involvement from
retroperitoneal or renal spread. Ultrasound shows internal vascularity within the mass and showing soft-
tissue attenuation with enhancement on contrast-enhanced CT. However, RLM is a cystic lesion (fluid
attenuation) with no vascularity . Associated features of retroperitoneal adenopathy, splenomegaly, or
lymphadenopathy at other sites are also seen in the case of renal lymphoma.
● Nephroblastomatosis is a rare pathologic process due to the presence of persistence embryogenic rests.
On ultrasound, the major feature is enlarged diffusely hypoechoic kidneys. On CT, there are poorly
enhancing soft tissue dense lesions intermingled with adjacent normally enhancing renal parenchyma.
RLM shows fluid attenuation on imaging as opposed to soft tissue attenuation seen with
nephroblastomatosis

13. RENAL LYMPHANGIECTASIA
OTHER NAMES
● Renal lymphangiomatosis
● Hygroma renale
● Polycystic disease of the renal sinus
● Renal lymphangioma
● Parapelvic lymphangiectasia

14. RENAL LYMPHANGIECTASIA
INTRODUCTION
● RLM accounts for approximately 1% of all lymphangiomas . It is very rarely reported benign
condition of lymphatic malformation where dilated peri-renal lymphatics are seen. The main
causative factor is non-communication of peri-renal and peri-pelvic lymphatic channels with
the main lymphatics . It has been reported in adults as well as in children of both sexes . It
may be unilateral or bilateral and focal as well as diffuse .Various spectrum of causes may
include familial, developmental and acquired causes. Mostly asymptomatic, it may show
nonspecific symptoms and is diagnosed by typical imaging findings. Usually, the renal
lymphatic ducts drain into larger retroperitoneal lymphatics. Failure of such drainage leads to
dilatation of these ducts and formation of unilocular or multilocular collections in perinephric
spaces or pelvic sinuses

15. RENAL LYMPHANGIECTASIA
PATHOPHYSIOLOGY
● Two patterns are recognized in the renal sinus. One of them originates
into intraparenchymal renal sinus region, known as peripelvic RLM and
the other one originates in the medial renal parenchyma and encroach in
the renal sinus which are called parapelvic RLM. Both appear same on
imaging. If radiological and pathological correlations data are not
available; both are commonly described as “cystic lesion of the renal
sinus”
● We found about 25% patients to have perinephric lymphangiectasia and
about 75% patients of peripelvic lymphangiectasia. However, no data in
literature for individual incidence of perinephric or peripelvic
lymphangiectasia were found.

16. CLINICAL PRESENTATION
The clinical presentation of this condition is quite variable. Commonly, it is
asymptomatic and diagnosed incidentally. However, it may show sudden appearance
and rapid growth or cessation of growth and spontaneous regression of symptoms .
However, when present the symptoms may be flank pain, abdominal mass, hematuria,
ascites, lower extremity edema, hypertension and renal failure . Renal function is
usually not impaired. The presence of hypertension is presumed to be due to
subcapsular collection causing compression of renal parenchyma and resulting in
excessive renin release.in children, it may also manifest with a palpable abdominal
mass, kidney enlargement or pyelonephritis .

17. IMAGING
● X-rays show an increase in the renal outline with displacement of the adjacent structures
if it is large. Excretory urography shows nephromegaly and hydronephrosis with distortion
of the pelvicalyceal system.
● Ultrasound studies reveal multiseptated thin-walled fluid collections in perinephric or
peripelvic regions with normal or enlarged kidneys . Renal cortical echo texture may be
normal or increased with preserved or lost corticomedullary differentiation. It may also
present as a solid mass when the small intra renal lymphatics are obstructed . Ascites
may also be seen on ultrasound.
● On CT scan, RLM appears as a well-defined low attenuation (0–20 HU density)
multiseptated collections in perinephric or peripelvic regions with normal renal
parenchymal enhancement and contrast excretion. Higher density fluid may represent
intra cystic hemorrhage. No evidence of invasion of other organs is seen by such
collection. The presence of fluid or fluid-filled lesions in the retroperitoneum around great
vessels and crossing the midline at the level of origin of renal vessels is typical CT sign of
RLM .These are the dilated renal lymphatics, which are draining in to larger
retroperitoneal lymphatics.

18. The typical appearance on MRI of lymphangiectasia consists of cystic lesions that
are hypointense on T1WI and hyperintense on T2WI. Also, the involved kidney
may be enlarged with increased cortical intensity and decreased medullary
intensity in T2WI. This could be explained by obstructed intrarenal lymphatics and
subsequent edema. Rarely, retroperitoneal perivascular tubular lesions may be
present, in keeping with enlarged lymphatic vasculature. Associated
retroperitoneal perivascular thin lymphatic channels seen in MRI .
The confirmation of diagnosis is done by percutaneous fluid aspiration and
cytology of aspirated fluid. The fluid in RLM appears to be sterile, chylous fluid
containing majority of lymphocytes (more than 90%), small amount of fat and
protein. High levels of renin in the aspirated fluid confirms the origin to be renal.

19. Greyscale ultrasound in the oblique sagittal plane of both kidneys (a: right kidney, b: left kidney) showing anechoic
collection with internal septations in the perinephric region on both sides

20. Axial (a) and coronal (b) contrast-enhanced CT of the abdomen in the delayed phase demonstrates bilateral
perinephric fluid collections (white arrows). The coronal image also demonstrates ascites (yellow arrow) and IVC
stent (red arrow)
CT: computed tomography; IVC: inferior vena cava

21. Gray-scale ultrasound image of right kidney (a) and left kidney (b) showing multiseptated anechoic collection (asterisk) in perinephric region. (c) CT
scan arterial phase in coronal plane showing multiseptated nonenhancing collection with average HU density 0–10 HU. (d) MPR reformation of
coronal plane of delayed phase of CT scan abdomen showing normal excretion of contrast.

22. Gray-scale ultrasound image (a) of right kidney showing anechoiec collection in perinephric region and (b) left kidney
showing multi septated anechoic collection in perinephric region. (c) CT scan arterial phase in coronal plane showing
nonenhancing collection (d) MPR reformation of coronal plane of delayed phase of CT scan abdomen showing normal
excretion of contrast.

23. TREATMENT & FOLLOW UP
● Usually, asymptomatic cases do not require treatment. Pain on account of compression due
to the presence of collection is usually relieved by percutaneous aspiration of fluid. However,
hypertension and altered renal function improve after conservative treatment .Asymptomatic
patients receive conservative management, but symptomatic large collections are treated by
mar-supialization or nephrostomy . Antihypertensive drugs can be used in hypertensive
patients for symptomatic relief. Page kidney and renal vein thrombosis are one of the rare
complications where nephrectomy is done as a treatment . However, nephrectomy is not
considered a choice nowadays, as in case of asymmetrical bilateral involvement, the cysts in
the contralateral kidney may increase in size .Antibiotic treatment is given only in cases of
secondary infection in the lesions and may decrease the cystic lesions and perirenal fluid
accumulation, which is associated with concomitant urinary tract infection.

24. COMPLICATIONS
● Untreated cases can be complicated by hematuria, ascites, hypertension, infection,
renal vein thrombosis or altered renal function .

25. SUMMARY
● Very few cases of renal lymphangiectasia have been described in the literature,
though most cystic renal lesions are benign simple cysts, complex and multifocal
cystic renal diseases are also common with a vast number of differentials. One of the
rare mimickers of this condition is renal lymphangiectasia, and the disease can be
diagnosed if radiologists are aware of the imaging findings, and this can help the
physician to offer the appropriate treatment.
● Renal Lymphangiectasia is a very rarely seen benign usually asymptomatic condition
where imaging studies can play a very important role in differentiation from other
conditions. Also, it can help in determining the extension of the fluid collection and
reduces the morbidity associated with it. In difficult cases, aspiration of fluid can
confirm the diagnosis and can avoid the unnecessary surgical interventions with
their associated complications. Awareness about this condition will result in early
diagnosis, early treatment and reduced morbidity.