pre sacral lesion sept5.pptx RADIOLOGY

PRE SACRAL LESIONS DIFERENTAL DIAGNOSIS RADIOLOGY

1. PRE – SACRAL LESIONS DR. SABHILASH SUGATHAN

2. The presacral space is an extraperitoneal potential space between the upper two-thirds of the rectum and the sacrum . Anteriorly - rectum and mesorectal fascia , Superiorly - peritoneal reflection of the rectosigmoid colon , Inferiorly - rectosacral/Waldeyer's fascia , levator ani Posteriorly - presacral fascia, sacrum, and coccyx Laterally - iliac vessels and ureters . CONTENTS – Osteochondral tissue from the sacrum and coccyx , Neural tissue from the cauda equina and branches of the sacral plexus, and Mesenchymal tissue from adjacentorgans , as well as surrounding Connective tissue , Blood and Lymphatic vessels .

3. CONDITIONS WITH AN OSTEOCHONDRAL ORIGIN

4. GIANT CELL TUMOR most common sacral tumors after chordoma 2nd–4th decades, F>M locally aggressive, lytic, destructive, expansile lesion, often in an eccentric location commonly involve both sides of the midline and may extend across the sacroiliac joints

5. CT - osteolytic or radiolucent lesion , soft-tissue mass within the bone; usually no surrounding sclerosis (80-85%) , the mass may have a thin sclerotic rim MR – T1 low to intermediate signal (solid component) low signal rim T2:  heterogeneous high signal with areas of low signal intensity due to hemosiderin or fibrosis  T1 C+ ( Gd ):  solid components will enhance

6. Giant cell tumor . (a) Lateral radiograph shows a lytic lesion involving S1 and S2 . (b) Sagittal T2-weighted MR image shows that the lesion has heterogeneous signal intensity . (c) Axial contrast-enhanced T1-weighted MR image shows that the lesion demonstrates intense enhancement . (d) Axial CT image obtained with bone window settings clearly shows lytic bone destruction .

7. EWING SARCOMA Three to ten percent of all primary Ewing sarcomas occur in the spine, but metastatic involvement is more common Ages Group - 5 and 30

8. Aggressive, demonstrating permeative bone lysis, osseous expansion , or sclerosis lamellated (onion skin) periosteal reaction Associated soft-tissue masses are common MRI - T1:  low to intermediate signal T1 C+ (Gd):  heterogeneous but prominent enhancement T2:  heterogeneously high signal, may see hair on end low signal striations IMAGING

9. T2-weighted images (Fig 3). Radiation and chemotherapy are the standard treatments for patients Ewing sarcoma in two patients. (a, b) Coronal contrast-enhanced T1- weighted (a) and sagittal T2-weighted (b) MR images show a large heterogeneous presacral mass with intermediate to high signal intensity at T2-weighted imaging and heterogeneous enhancement

10. CHONDROSARCOMA malignant cartilaginous tumors  mean age at the time of presentation is 45 years manifest with pain and a palpable mass

11. Plain radiograph – l ytic (50%) intralesional calcifications: ~70% ( rings and arcs calcification  or  popcorn calcification ), characteristic chondroid matrix endosteal scalloping : affecting more than two-thirds of the cortical thickness   moth-eaten appearance or  permeative appearance  in higher grade tumors CT – attenuation of the non-mineralized portion is often lower than that of muscle due to the relatively high water content of hyaline cartilage IMAGING

12. MRI – T1:  low to intermediate signal. T2:  very high intensity in non-mineralized/calcified portions - the cartilage is a hydrophilic tissue with high water content gradient echo/SWI:  blooming of mineralized/calcified portions. T1 C+ (Gd)  : enhancement can be septal and peripheral rim-like corresponding to fibrovascular septation between lobules of hyaline cartilage -  rings and arcs enhancement pattern most demonstrate heterogeneous moderate to intense contrast enhancement.

13. Chondrosarcoma in a patient with multiple hereditary exostoses . (a) Axial radiograph of the pelvis shows multiple osteochondromas (arrowheads). An area of increased opacity is also seen in the lower sacrum, with areas of faint calcification. (b, c) Coronal T2- weighted (b) and sagittal contrast-enhanced T1-weighted (c) MR images show a large presacral mass with increased signal intensity at T2-weighted imaging and intense contrast enhancement.

14. CONDITIONS WITH A NEUROGENIC ORIGIN

15. NEUROFIBROMAS benign neural tumors Neurofibromas most often occur in isolation, although multiple tumors may occur in patients with neurofibromatosis type 1 (NF1)

16. Imaging CT – well-defined hypodense mass low attenuation lower than that in adjacent soft tissues minimal or no contrast enhancement may resemble lymphadenopathy MRI – T1:  hypointense T2 : hyperintense target sign a hyperintense rim ( myxoid material ) and central area of a low signal (dense central area of collagenous stroma ) may be seen although this sign is highly suggestive of neurofibroma , it is occasionally also seen in  schwannomas  and  malignant peripheral nerve sheath tumors fascicular sign T1 C+ ( Gd ):  heterogeneous enhancement

17. Plexiform neurofibroma in two patients. (a) Axial CT image shows an area of low attenuation in the sacral plexus, a characteristic finding of plexiform neurofibroma . (b) Sagittal T2-weighted MR image obtained in another patient shows the target sign (arrows) in the sacral plexus, a finding characterized by an area of high signal intensity with a central area of low signal intensity that is suggestive of plexiform neurofibroma

18. SCHWANNOMAS benign  nerve sheath tumors peak incidence in the 5 th  to 6 th  decades When they occur in patients with  neurofibromatosis type 2 (NF2) , schwannomas usually present by the 3 rd  decade Multiple schwannomas are characteristic of neurofibromatosis type 2 large mass, and they may remodel or erode through the sacral bone

19. well-circumscribed masses which displace adjacent structures without direct invasion cystic and fatty degeneration is common  calcification is rare CT – heterogeneous presacral soft-tissue mass, with or without calcifications. intense contrast enhancement adjacent bone remodeling with smooth corticated edges MR – T1:  isointense or hypointense T1 C+ (Gd):  intense enhancement T2:  heterogeneously hyperintense, cystic degenerative areas may be present, especially in larger tumors T2*:  larger tumors often have areas of hemosiderin Imaging

20. Schwannoma in two patients. (a) Axial T2-weighted MR image shows a high-signal-intensity presacral mass with scattered cystic areas. (b) Sagittal contrast-enhanced T1-weighted MR image shows that the mass demonstrates heterogeneous enhancement. (c) Axial contrast-enhanced CT image in another patient shows a heterogeneously enhancing presacral mass.

21. PERINEURAL CYSTS CSF -filled dilatations of the  nerve root sheath  at the  dorsal root ganglion  (posterior nerve root sheath) most commonly occur at the level of the second and third sacral nerve roots cyst wall is continuous with the arachnoid and dura, and the cyst cavity occupies the space between the perineurium and endoneurium may be congenital or traumatic Stenosis of the ostium of the nerve root sheath allows cerebrospinal fluid (CSF) to flow in with arterial pulsation and restricts outflow

22. CT – cystic mass that is isoattenuating relative to CSF at the neural foramina Bone remodeling and enlargement of the neural foramina may be seen, a result of increased CSF pressure Because communicate with CSF, perineural cysts fill with contrast material at CT myelography MRI – T1:  low signal T2: high signal  will show chemical shift at fat-fluid boundary with epidural fat T1 C+:  no enhancement DWI/ADC:  facilitated diffusion ~3000 x 10 -6  mm 2 /s Imaging

23. A peri-neural cyst at the level of S2 segment lateralizing to right with smooth scalloping of the related bony skeleton and mild effacement of the related right sided sacral nerve roots

24. DURAL ECTASIA ballooning or widening of the dural sac which can result in posterior vertebral scalloping and is associated with herniation of nerve root sleeves. defective microfibrils weaken the dural sac, usually in the lumbosacral spine, where CSF pressure is greatest, which leads to incompetence Dural ectasia is present in 56%–65% of patients with Marfan syndrome

25. widening of the interpediculate distance and posterior vertebral body scalloping Widening of the dural sac, dilatation of the nerve root sleeves, and scalloping of the posterior vertebral bodies may be seen in the lumbosacral spine Dural ectasia in a patient with Marfan syndrome. Axial contrast-enhanced CT images obtained with bone (a) and soft-tissue (b) window settings show dural ectasia with bone remodeling in the sacral foramina.

26. ANTERIOR MYELOMENINGOCELES Anterior myelomeningoceles occur when the dural sac herniates through a defect in the anterior surface of the sacrum Dural sac is composed of both the outer dura and the inner arachnoid membranes, and it contains CSF and, occasionally, neural elements manifest in the 1st decade of life Currarino triad, which comprises an anorectal malformation, a sacrococcygeal osseous defect, and a presacral mass. The associated presacral mass may be a teratoma , anterior sacral meningocele , dermoid cyst, hamartoma , or enteric duplication cyst and is autosomal dominant in more than 50% of patients. classic clinical presentation of headache during valsalva owing to increased cerebrospinal fluid (CSF) pressure transmitted via the connection between the meningocele and subdural space

27. Imaging pelvic radiographs - unilateral anterior sacral defect may be seen with a rounded, concave border with scalloping/destruction of the surrounding bone, often referred to as the “scimitar sign” CT - Osseous defects, such as vertebral body scalloping, hypoplasia, and aplasia, may accompany an anterior sacral meningocele and are best assessed at CT MRI - the signal intensity of the content within the meningocele should parallel the CSF signal on all sequences Biopsy and aspiration should not be performed, given the risk of introduction of pathogens directly into the spinal meninges, which can result in meningitis.

28. Well defined, rounded defect in the lower sacrum with a huge fluid collection in the pelvis communicating with the spinal thecal sac - typical of a sacral meningocoele . MRI confirms the CT findings indicating that the huge fluid collection in the pelvis is connected to the thecal sac and is not the bladder or other pathological cyst.

29. A 17-year-old-male with anterior sacral meningocele. Sagittal T 2 weighted image showing a sacral defect (black arrow) and a small anterior cystic mass with demonstrable direct communication with the dural sac (white arrow).

30. rare congenital lesions with female predominance associated with other congenital anomalies - spina bifida, tethered spinal cord, imperforate anus, uterine/vaginal duplications and presacral lipomas classic clinical presentation of headache during valsalva owing to increased cerebrospinal fluid (CSF) pressure transmitted via the connection between the meningocele and subdural space ANTERIOR SACRAL MENINGOCELE

31. pelvic radiographs - unilateral anterior sacral defect may be seen with a rounded, concave border with scalloping/destruction of the surrounding bone, often referred to as the “scimitar sign” MRI - the signal intensity of the content within the meningocele should parallel the CSF signal on all sequences Biopsy and aspiration should not be performed, given the risk of introduction of pathogens directly into the spinal meninges, which can result in meningitis. Surgical resection is curative as long as the dural defect is closed, and a posterior approach is generally taken, although large lesions may require an anterior approach. Imaging

32. PARAGANGLIOMAS neuroendocrine neoplasms that arise from the paraganglia , accessory organs of the peripheral nervous system Typically, spinal paragangliomas are intradural, extramedullary lesions located in the region of the cauda equina and filum terminale more common in men,

33. Paragangliomas are highly vascular tumors that demonstrate an intense, early blush at angiography that persists into the late arterial and early venous phases well-circumscribed mass that is isointense on T1-weighted MR images and iso- to hyperintense on T2-weighted Hemorrhage is common, and a low-signal-intensity rim (the cap sign) may be seen. Intense enhancement is seen on contrast-enhanced images, and flow voids are common

34. Paraganglioma in a pregnant woman. Axial (a) and sagittal (b) T2-weighted MR images show a large presacral mass that is iso - to hyperintense with a hypointense rim, a finding known as the cap sign.

35. CHORDOMAS most common primary sacral tumor from notochordal rests and are limited to the clivus, spine, and sacrum on the basis of their cell of origin typically located in the midline or paramedian region most common in the 4th–7th decades of life

36. Chordomas are destructive lytic lesions that may extend across the sacroiliac joints Calcification is common in sacrococcygeal lesions large presacral soft-tissue component is present, with soft tissues extending into the sacral canal. CT centrally located well-circumscribed destructive lytic lesion, sometimes with marginal sclerosis expansile soft-tissue mass soft-tissue mass is often disproportionately large relative to the bony destruction irregular intratumoral calcifications (thought to represent sequestra of normal bone rather than dystrophic calcifications) moderate enhancement  low to intermediate signal intensity on T1-weighted MR images and high signal intensity on T2-weighted variable, often only moderate, contrast enhancement

37. Chordoma . (a) Axial contrastenhanced CT image shows a homogeneous mass anterior to the distal sacrum and coccyx. (b) Sagittal T2-weighted MR image shows the hyperintense mass. (c) Axial contrast-enhanced T1-weighted MR image shows that the mass demonstrates only mild enhancement.

38. CONDITIONS WITH A MESENCHYMAL ORIGIN

39. HEMANGIOMAS most common soft-tissue abnormality most common tumors in infants and usually appear within the 1st week of life three times more common in girls

40. Imaging intermediate signal intensity on T1-weighted MR images and high signal intensity and flow voids on T2-weighted images On T2-weighted images, clusters of high-signal-intensity lobules indicate cystic vascular spaces that contain stagnant blood. Areas of increased signal intensity on T1- and T2- weighted images correlate with haemorrhage and areas of fat deposition. Phleboliths are common and appear as low-signal-intensity foci on both T1- and T2-weighted images.

41. Perirectal hemangioma in two patients. (a) Sagittal short inversion time inversion-recovery MR image shows a perirectal mass with heterogeneous high signal intensity. (b) Axial contrast-enhanced T1-weighted MR image shows that the mass demonstrates heterogeneous enhancement. (c) Axial contrast enhanced CT image obtained in another patient shows phleboliths, a typical finding of perirectal hemangioma.

42. MYELOLIPOMA benign tumors composed of mature fat and scattered hematopoietic cells

43. CT - they typically appear as a hypovascular mass that contains macroscopic fat with areas of soft-tissue attenuation interspersed T1-weighted MR imaging, the fatty areas have high signal intensity that drops out when fat is suppressed. Imaging

44. Myelolipoma. Axial contrast-enhanced CT image shows a well-circumscribed presacral mass with macroscopic fat. (b, c) Axial (b) and sagittal (c) T1-weighted MR images show that the areas of fat demonstrate increased signal intensity. (d) Sagittal T1-weighted fat-suppressed MR image shows dropout of signal intensity in the areas of fat.

45. SOLITARY FIBROUS TUMORS slow-growing mass in middle-aged adults Solitary fibrous tumors are mesenchymal tumors of fibroblastic or myofibroblastic origin

46. Imaging CT - well-circumscribed mass with soft-tissue attenuation that typically demonstrates intense contrast enhancement Areas of hemorrhage , necrosis, and cystic change may be seen. MRI - low to intermediate signal intensity on T1- and T2- weighted MR images a result of fibrous tissue, but areas of myxoid or cystic degeneration may demonstrate high signal intensity on T2-weighted images. Hypervascularity with prominent enhancement and flow voids is common.

47. Solitary fibrous tumor . Axial contrast-enhanced CT image shows a homogeneous mass that is isoattenuating relative to muscle. Sagittal T1-weighted MR image shows flow voids (arrows) in the low-signal-intensity mass. (c, d) Axial (c) and coronal (d) contrast-enhanced T1-weighted MR images show that the mass demonstrates intense enhancement. (e) Angiogram shows the tumor , which demonstrates increased vascularity

48. RETROPERITONEAL FIBROSIS most commonly manifests as an isolated fibrotic plaque centered over the lower lumbar spine

49. Imaging At CT , the plaque may be midline or asymmetric and may be well-circumscribed or poorly defined. It demonstrates soft-tissue attenuation and variable contrast enhancement, with immature plaque demonstrating greater enhancement. hypo- to isointense on both T1- and T2- weighted MR images; an area of hyperintensity is concerning for inflammatory edema or an associated malignancy

50. Retroperitoneal fibrosis. (a) Axial contrast-enhanced CT image shows an ill-defined presacral mass. (b) Axial contrast-enhanced T1-weighted MR image shows that the mass demonstrates enhancement. (c) T2-weighted MR cholangiopancreatographic image shows bilateral hydronephrosis , a result of fibrosis surrounding the distal ureters.

51. LYMPHOMAS CT - lymphomas have soft-tissue attenuation with homogeneous enhancement MR imaging , they are characterized by an area of low signal intensity on T1-weighted images and an area of high signal intensity on T2-weighted images

52. Non-Hodgkin–type B-cell lymphoma. (a) Axial contrast-enhanced CT image shows an abnormal area of homogeneous enhancement in the rectal and perirectal soft tissues. (b) Positron emission tomographic (PET)/CT image shows an area of intense uptake that corresponds to the abnormal rectal and perirectal soft tissues seen at CT

53. GASTROINTESTINAL STROMAL TUMORS most commonly occur in older patients and have a slight male predominance Gastrointestinal stromal tumors usually involve the outer muscular layer and tend to be exophytic. When located in the anorectal region, they tend to expand to the rectal wall, resulting in a focal well-circumscribed mural mass

54. Imaging CT - soft-tissue attenuation with a central area of low attenuation resulting from hemorrhage , necrosis, or cyst formation. Peripheral enhancement is common MRI - uniform intermediate signal intensity is seen on T1-weighted MR images and an area of heterogeneous high signal intensity is seen on T2-weighted images, with heterogeneous enhancement. Extension into the ischiorectal fossa, prostate, or vagina may be present.

55. Gastrointestinal stromal tumor in two patients. (a) Axial contrast-enhanced T1-weighted MR image shows a perirectal presacral mass that demonstrates intense enhancement. (b) Sagittal T2-weighted MR image in another patient shows a larger mass with heterogeneous signal intensity.

56. CONGENITAL AND DEVELOPMENTAL CONDITIONS

57. DEVELOPMENTAL CYSTS Developmental cysts are the most common congenital condition in the presacral space and include epidermoid , dermoid , enteric, tailgut (also known as retrorectal cystic hamartoma ), and duplication cysts female predilection 13% of these cysts may undergo malignant transformation, and for this reason, they are removed its typically manifest during childhood, and they are relatively rare in adults. Tailgut cysts are the most common asymptomatic presacral lesions that are incidentally found in adults

58. Tailgut cysts are often multiloculated cysts containing mucin and lack a muscular layer, a differentiating feature from rectal duplication cysts, which can be confirmed on endorectal ultrasound Rectal duplication cysts may be associated with other congenital abnormalities of the anorectal region and bladder/urethra. Sacrococcygeal teratoma is the most common presacral mass in children containing all three germ-cell lineages. Benign mature teratomas tend to be predominantly cystic containing fat, sebum, calcification and soft tissue from dermoid plugs.

59. Thin-walled and may be uni - or multilocular. USG - Internal echoes related to mucoid material or inflammatory debris may be seen. CT – low attenuation , with no associated enhancement, and associated thin calcifications are rare If secondarily infected - thick-walled with surrounding inflammatory change, and they may contain air if a fistula is present. MRI – hypointense on T1 (although they may be hyperintense if they contain mucoid material), hyperintense on T2. Focal irregular wall thickening with enhancement is suggestive of malignant degeneration Imaging

60. Rectal duplication cyst. (a) Sagittal T2-weighted MR image shows a large hyperintense presacral cystic mass. (b) Coronal contrast-enhanced T1-weighted MR image shows a thin area of peripheral enhancement around the mass.

61. ON IMAGING - CONGENITAL DEVELOPMENTAL CYSTS, well defined, unilocular or multilocular, cystic masses ranging from simple to complex in their internal contents A 45-year-old-female with tailgut cyst. (a) Axial T 2 weighted, (b) fat-saturated pre-contrast and (c) fat-saturated post-contrast subtraction T 1 weighted images (T1WI) through the pelvis showing a presacral multiloculated cystic mass posterior to the rectum without post-contrast enhancement (arrows in a, c). High signal intensity on pre-contrast T1WI (arrow in b), suggesting haemorrhage or proteinaceous debris. Surgical resection confirmed tailgut cyst.

62. Tailgut cyst. (a) Axial T2-weighted MR image shows a hyperintense multilocular cystic mass. (b) Axial contrast-enhanced T1- weighted MR image shows a thin rim of peripheral enhancement around the mass. (c) Endoscopic US image shows that the cystic areas are anechoic, with increased through-transmission and thin internal septa.

63. CONGENITAL