Renal cyst / Classification of Renal Cyst

Renal Cysts are very common. Find here a compact presentation on Renal Cyst.

1. CASE PRESENTATION BY Dr. Muhammad Saifullah PG Trainee, Department of Urology, AHF

2. INTRODUCTION Mr. X.Y.Z , 48 years old, married & resident of Batala colony, Faisalabad was admitted via OPD with the presenting complaint of Pain Right Lumbar Region – 9 months Swelling Right Lumbar Region – 3 months

3. HISTORY The patient was in usual state of health 9 months back when he experienced gradual onset mild pain over the Right lumbar region. This pain was dull in nature, radiated to the back and was not associated with fever, vomiting or hematuria . This pain was non-progressive, aggravated by itself & was relieved by oral medication (No record available)

4. 6 months later, he noticed swelling over the Right lumbar region when he was taking bath. The swelling was initially small but was gradually progressive . This swelling was also not associated with fever, vomiting or hematuria.

5. PAST HISTORY No history of any previous similar episode. Known case of Heart disease – 20 years History of Appendectomy – 15 years History of open reduction and internal fixation of Left Radius & Ulna – 10 years

6. FAMILY HISTORY No family history of DM, HTN, TB or IHD. Both parents alive and healthy. Govt. Employee. Smoker – 30 years. Middle socio-economic class. SOCIAL HISTORY

7. GENERAL PHYSICAL EXAMINATION A middle aged man of average built lying comfortably on the couch with following vitals: Pulse…. 88/min BP…. 110/70 R/R…. 16/min Temp…. 98.6 o F

8. NAILS… No Pallor, clubbing, koilonychia , splinter hemorrhages or cyanosis. FINGERS… No Osler’s, Heberden’s or Bouchard’s nodes, Joint swelling or deformity. PALM… No sweating, palmar erythema or dupuytren’s contracture. FACE… No puffiness, proptosis , jaundice, xanthelasmas or central cyanosis. Good oro -dental hygiene. NECK… No thyroid swelling, engorged neck veins or palpable cervical lymph nodes. FOOT… No edema, cyanosis or loss of hair.

9. ABDOMINAL EXAMINATION Abdomen scaphoid with normal shaped umbilicus, central in position. Peristalsis not visible. Fullness of Right Lumbar region . No visible scars, striae or veins. Hernial orifices are intact. Abdomen was soft and non-tender. A cystic non-tender mass palpable occupying the Right lumbar region which was not reducible or compressible. Kidneys billaterally not palpable . No visceromegaly .

10. Abdomen was resonant on percussion except right lumbar region where dullness was present. No Shifting dullness . Bowel sounds 2-3 per minute with no audible bruits or succussion splash. DRE. Normal Rest of the examination was unremarkable.

11. INVESTIGATIONS HB  14.3 mg/dl E.S.R  12 after 1 st hour T.L.C  7,700 neutrophils 79 % lymphocytes 16 % monocytes 03 % eiosinophills 03 % Platelets count  1,28,000

12. R.B.S  96 Urea  44 mg/dl Creatinine  0.7 mg/dl Billirubin total  0.8 SGOT(AST)  38 Alk phosphatase  211 HbsAg ---> neg Anti Hcv ---> neg

13. ECG

14. Echocardiography

15. Ultrasound KUB

16. Cystogram

17. CT Scan KUB with contrast

18. LITERATURE REVIEW

19. OUTLINE Introduction Simple Cysts Differentials Complex/Complicated Cysts BOSNIAK Classification Management according to BOSNIAK Categories

20. CYST A  cyst  is a closed sac, having a distinct membrane and division compared to the nearby tissue. Cyst is a Greek word meaning “Fluid Filled Sac” It may contain  Air Fluids Semi-solid material

21. If this cavity lacks a distinct membrane, it is called PSEUDOCYST . If it is filled with pus, it is called an ABSCESS .

22. RENAL CYST A  renal cyst  is a fluid collection in the kidney.

23. 27-35 % of individuals greater than 50 years of age may have asymptomatic simple renal cysts. Prevalence increases with increasing age and by the age of 70 years almost every person has a simple renal cyst.

24. SIMPLE CYSTS Simple cysts arise from obstructed tubules or ducts. They do not communicate with collecting system. Commonly asymptomatic Hematuria (from cyst rupture) Infection (Abscess) Mass effect from large cysts may cause dull ache or discomfort.

25. HYPERDENSE CYST A hyperdense cyst a simple kidney cyst that has blood as part of the contents of the cyst. A hyperdense kidney cyst is not suspicious for kidney cancer and is just another type of simple kidney cyst.

26. Intravenous Urography A lucent mass may be seen within the renal parenchyma. A "claw" sign may be seen if the cyst extends beyond the surface of the kidney, and represents the adjacent stretched parenchyma. If the cyst is completely intrarenal , the thickness of its wall cannot be assessed. Radiographs taken 1-2 minutes after IV contrast injection optimally visualize a cyst. 

27. Lucent defect Cortical bulge Round indentations on collecting system "Beak sign" can be seen with large cysts .

28. Radiographic features , US: Anechoic Enhanced through-transmission Sharply marginated , smooth walls

29. Radiographic features , CT: Smooth cyst wall Sharp demarcation Homogenous Water density (< 10-15 HU) No significant enhancement after IV contrast (<5HU) Cyst wall too thin to be seen by CT

30. Be Careful : Cysts that contain calcium, septations , and irregular margins (complicated cysts) need further workup True renal cysts should always be differentiated from hydronephrosis , calyceal diverticulum , and peripelvic cysts. Differentiate renal cyst from hypoechoic renal artery aneurysm using color Doppler US and Angiography

31. Hydronephrosis :

32. Calyceal Diverticulum Parapelvic Cyst

33. Renal Artery Aneurysm

34. Complicated CYSTS Complicated cysts are cysts that do not meet the criteria of simple cysts and thus require further workup . Internal debris Echogenic clot Fluid-debris levels Thick septations Thick walls Thick or coarse calcification

35. Increased CT density (> 15 HU) of cyst content Vast majority of these lesions are benign. High density is usually due to hemorrhage, high protein content, and/or calcium. Radiographic Features of Complicated Cysts Septations Thin septa within cysts are usually benign. Thick or irregular septa require workup. Calcifications Thin calcifications in cyst walls are usually benign. Milk of calcium: collection of small calcific granules in cyst fluid: usually benign Thick wall These lesions usually require surgical exploration.

36. BOSNIAK CLASSIFICATION of RENAL CYSTS

37. BOSNIAK Category I Benign simple cyst with: Thin wall without septa No calcifications No solid components No contrast enhancement. Density equal to that of water

38. Simple renal cyst, Bosniak Category I.

39. BOSNIAK Category II Benign cyst with A few thin septa May contain fine calcifications Homogenous lesions less than 3 cm with sharp margins Without enhancement

40. Bosniak Category II cyst Curvilinear calcification within a thin septum

41. Bosniak Category II cyst Homogeneously hyperdense mass No increase in Density after IV contrast

42. Bosniak Category II cyst Cyst with several internal septations and a minimally thickened wall

43. Bosniak Category II cyst. Cyst with uniform, mild wall thickening and short, interrupted calcifications

44. Bosniak Category II hyperdense cyst.

45. Bosniak Category II cyst

46. Bosniak Category II cyst. Nearly completely calcified mass with no obvious enhancing elements

47. Bosniak Category II. subcentimeter rim calcified renal cyst

48. BOSNIAK Category IIF Well marginated cysts with A number of thin septa, with or without mild enhancement or thickening of septa. Thick and nodular calcifications may be present No enhancing soft tissue components Non enhancing lesions 3 cm or larger.

49. BOSNIAK Category IIF

50. BOSNIAK Category III Indeterminate cystic masses with thickened irregular septa with enhancement. multilocular , encapsulated mass Increase in Hounsfield Units of the mass after contrast injection….. ENHANCEMENT (> 15% = enhancement = surgical on MRI)

51. Bosniak Category III. cystic mass with irregular wall thickening and associated heterogeneous nonenhancing elements

52. Bosniak Category III complex cyst. multilocular , encapsulated mass

53. Bosniak Category III complex cyst. Thick-walled, encapsulated, multilocular cystic mass with enhancing septa

54. BOSNIAK Category IV Malignant cystic masses with All the characteristics of category III lesions Enhancing soft tissue components independent of but adjacent to the septa.

55. Bosniak Category IV cystic neoplasm.

56. Bosniak Category IV cystic neoplasm

57. A 42-year-old female with back pain, hematuria, and a renal mass discovered by lumbar spine MR. hyperdense (55 HU) 3 cm mass. enhance to 88 HU after IV contrast Renal cell carcinoma

58. BOSNIAK CLASSIFICATION Category ( Bosniak ) US Features Workup Type 1: Simple cyst Round, anechoic, thin wall enhanced through transmission None Type 2: Mildly complicated cyst Thin septation , calcium in wall CT or US follow-up Type 3: Indeterminate lesion Multiple septae , internal echos mural nodules Thick septae Partial nephrectomy , biopsy CT follow-up if surgery is high risk Type 4: Clearly malignant Solid mass component Nephrectomy

59. To identify size criteria for complex cystic renal masses that can distinguish renal cell carcinoma from benign cysts supplementing the Bosniak classification

60. To identify size criteria for complex cystic renal masses that can distinguish renal cell carcinoma from benign cysts supplementing the Bosniak classification

61. To identify size criteria for complex cystic renal masses that can distinguish renal cell carcinoma from benign cysts supplementing the Bosniak classification Malignancy was significantly associated with cyst size (>2 cm) male gender younger patient age (<50 years). According to the Bosniak classification, no category I cyst all 8 category II cysts were benign 3 of 18 (17%) category IIF cysts were malignant 21 of 39 (54%) category III cysts were malignant 29 of 32 (90%) category IV cysts were malignant. All category IIF cysts were benign in patients older than 50 years of age

62. Treatment Treatment is not needed for asymptomatic simple kidney cysts.   Simple kidney cysts may be monitored with periodic ultrasounds. Simple kidney cysts that are causing symptoms or blocking the flow of blood or urine through the kidney may need to be treated using a procedure called sclerotherapy . If the cyst is large, surgical excision may be needed.

63. In SCLEROTHERAPY , the doctor punctures the cyst using a long needle inserted through the skin. Ultrasound is used to guide the needle to the cyst. The cyst is drained and then filled with a solution containing alcohol to make the kidney tissue harder. The procedure is usually performed on an outpatient basis with a local anesthetic.

64. MANAGEMENT Ignore, Follow or Excise Renal cysts can be classified according to the Bosniak classification depending on their features.  Type I  cysts are simple cysts. Type II  are the minimally complicated cysts.  Type I and II can be ignored. 

65. Type II F  are probably benign, but need to be followed.  Type III and IV  both are surgical lesions.  Type IV is inevitably malignant and in the type III group about 80-90% turn out to be malignant as well

66. ANY QUESTIONS ??????