tarlov cysts ( tcs ) also known as perineural cysts , are pathological dilatations,[13 ] located in between the peri and endoneural spaces of the spinal posterior nerve root sheath . tcs usually are found in the spine and do not require surgical intervention unless symptomatic . the typical clinical presentation includes back pain , coccyx pain , low radicular pain , bowel or bladder dysfunction , lower limb weakness , sexual dysfunction , and infertility . these cysts are usually diagnosed by magnetic resonance imaging ( mri ) and can often be demonstrated by ct myelography to communicate with the spinal subarachnoid space . our patient is a 62-year - old indian male who presented to orthopedics department with a vague history of low back ache , gradually increasing in intensity with no other associated symptoms . no motor deficits were noted on neurological examination . a whole body bone scan was advised to rule out any skeletal pathology . tc methylene diphosphonate ( technetium mdp ) three - phase whole body bone scan was performed with 555 megabecqueral of 99mtc mdp intravenous injection . initial dynamic images of pelvis followed by 3 hrs delayed high - resolution anterior and posterior whole body images were acquired using a dual head variable angle e cam gamma camera . an abnormal focal site of mdp uptake was noted in the sacrum s2 level indicating sacral osteoblastic activity of uncertain etiology . on further evaluation with contrast - enhanced mri of lumbosacral spine , a cystic lesion was reported in right neural foramen of s2 of 25  15  25 mm size whose intensity was the same as cerebrospinal fluid ( csf ) suggesting tc . similar lesions were also noted in s1 , right t3-t4 , right t7-t8 , and left t6-t7 neural foramina but with no corresponding hot spots in mdp bone scan . initial and a 6-h delayed ct myelography showed no free communication between cyst and subarachnoid space . however , there was surrounding sacral bony erosion around this cyst [ figures 13 ] . ( a ) lumbo - sacral contrast enhanced magnetic resonance imaging shows a cystic lesion in right neural foramen at s2 level , 25  15  25 mm in size ( b ) tc mdp bone scan shows a hot spot corresponding to above lesion . similar lesions were also noted in s1 , right t3-t4 , right t7-t8 and left t6-t7 neural foramina but with no corresponding hot spots in bone scan a three phase tc99 m labeled methylene diphosphonate bone scan showing focal hot spot in sacrum ( arrow ) with no increased vascularity 99mtc mdp whole body bone scan - skeletal phase images showing focal hot spot in sacrum ( arrow ) with normal tracer distribution in rest of skeletal survey myelo computed tomography of pelvis . initial and a 6-h delayed computerized tomography scans revealed no free communication between the tarlov cyst ( tc ) and subarachnoid space . however , surrounding sacral bony erosion around tc in s2 level produced the increased mdp uptake in the bone scan as a result of new bone formation the incidence does not significantly differ between sexes but is more prevalent in younger people : 4.0% in people less than 50 years of age versus 1.3% in people over 50 years . tcs are defined as csf - filled saccular lesions located in the extradural space of the sacral spinal canal and are formed within the nerve root sheath at the dorsal root ganglion . although the terminology of tc is synonymous for any cystic spinal lesions , the most common incidental lumbosacral lesions identified by mr are vertebral hemangiomas , perineural cysts , fibrolipomas , synovial cysts , and sacral meningoceles . and their pathological confirmation rests on the fact that their cyst walls are composed of perineurium and neural tissue . the cysts show membranous tissue walls , with peripheral nerve fibers and ganglionic cells embedded into connective tissue . voyadzis , et al . , found nerve fibers in the walls of the cysts in 75% of their patients . the cysts in tcs are usually formed by the dilated sheaths between the peri and endoneural spaces of the spinal posterior nerve root sheath having microconnections to the subarachnoid space . thus , when pulsatile and hydrodynamic forces of csf , through a ball - valve mechanism , cause these perineural cysts to fill and expand in size , they can begin to compress neighboring nerve fibers , resulting in neurological symptoms . the ball - valve theory has been previously postulated as the reason why some large tcs cause symptoms that progress , whereas others cause only mild symptoms . due to the valve like mechanism and gravitational pressure within the cyst , the cysts are often multiple and can erode surrounding sacral bony structures , causing irritation of the periosteal pain fibers and insufficiency fractures . the other type of tcs , so - called un - valved cysts ( with no csf cross - connections ) are usually asymptomatic . , into three different types : 
 type i : extradural meningeal cysts without spinal nerve root fibers;type ii : extradural meningeal cysts with spinal nerve root fibers ( i.e. , tcs ) ; andtype iii : spinal intradural meningeal cysts . type i : extradural meningeal cysts without spinal nerve root fibers ; type ii : extradural meningeal cysts with spinal nerve root fibers ( i.e. , tcs ) ; and type iii : spinal intradural meningeal cysts . a few of the important reasons put forward are inflammation of nerve root cysts followed by fluid collection , arachnoidal proliferation along and around the sacral nerve root , post - traumatic disruption of peri and epineural venous drainage secondary to hemosiderin deposition , other developmental or congenital factors apart from trauma have been reported in 40% cases . patients can have a myriad of symptoms along with low back ache , which are typically accentuated by coughing , standing , and change of position explained by the increasing csf pressure due to the ball - valve flow effect . mr is the gold - standard investigation in identifying tcs , and to study their relationship with surrounding structures . bone scan is highly sensitive and can easily identify early bony involvement and helps to plan surgical treatment when necessary . conventional mr imaging shows the cyst to be a fluid - filled lesion with low signal on t1-weighted images and high signal on t2-weighted images ( i.e. , csf signal ) . sacral vertebral body involvement can be identified by planar or spect - ct ( single photon emission computed tomography  computed tomography ) bone scan apart from mr and ct images . localization of mdp to sites of new bone formation is through chemisorption showing high degree of sensitivity for this imaging . there is limited role for ct here and is mainly advised for percutaneous aspiration treatment of the cysts . development of ct myelography , an invasive imaging modality , has led to an improvement in our ability to diagnose tcs  as a cause of sacral radiculopathy and to show any communication of these cysts with the spinal subarachnoid space . these cysts can enlarge due to inflow of csf , ultimately producing symptoms due to distorting , compressing , or stretching of adjacent sacral nerve roots . conservative management includes analgesics , physiotherapy , lumbar csf drainage , and ct - guided cyst aspiration , neither of which prevents symptomatic cyst recurrence . neurosurgical techniques for symptomatic perineural cysts include simple decompressive laminectomy , cyst and/or nerve root excision . and microsurgical cyst fenestration and imbrication . care must be taken in preserving nerve fibers of the parental nerve roots , which lie directly on the walls of the cyst . although no consensus exists on the definitive treatment of symptomatic tcs , surgical methods have yielded the best long - term results to date . based on patient symptoms , bone scan , and mr findings of sacral erosion , our patient underwent s2 cyst fenestration , partial cyst wall resection with myofascial cutaneous flap closure reinforcement surgery [ figure 4 ] . histopathology - a photomicrograph showing irregular cystic wall composed of dense collagenous bundles including neural tissue along with vascular structures ( h and e , 200 ) . sacral tcs are incidentally detected benign pathologies which may or may not require immediate management . however , this case is a reminder that multiple perineural tcs can be a cause of nerve roots injury , and their lumbosacral location can lead to cauda equina syndrome , without disc herniation or other cause of vertebral canal stenosis . both mri and bone scan can be used as an effective screening tool to survey the whole body in a single sitting and can help in guiding early management .
with technological advancements and wider availability of multimodality imaging , incidental lesions are frequently identified in patients undergoing various imaging studies . 
 we report here a case of multiloculated disseminated perineural or tarlov cysts ( tcs ) . 
 the primary aim of this case study was to ( 1 ) provide a comprehensive review of the clinical , imaging , and histopathological features of tcs ( 2 ) to draw attention to the fact that multiple lumbosacral and dorsal tcs can produce nerve injuries and serious movement disturbances , and ( 3 ) to document the usefulness of the magnetic resonance imaging and bone scan in non - invasive diagnosis and guiding management in such cases . 
 these cysts are clearly identified by magnetic resonance imaging ( mri ) and computerized tomography imaging of the lumbosacral spine . however , there are no reports on the scintigraphic findings of multilocular disseminated tc in literature . 
 tcs are typically benign , asymptomatic lesions that can simply be monitored . to date 
 , no consensus exists about the best surgical strategy to use when indicated .