A 35 years old male came with complaints of low back

ache radiating to right lower limb and is associated

with tingling numbness and thin stream of urine since 1

year. Radiograph lumbo-scaral spine came out to be

normal and thus MRI lumbo-sacral spine was done

which revealed an intramedullary spinal tumour.

Subsequent CT scan was done for the patient. Considering

the tumour characteristics, diagnosis of

intramedullary dermoid was made

Abhijit Patil

Aditi Gujarathi

Kulkarni Vilas M.

Naware S. S.

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 Journal of Krishna Institute of Medical Sciences UniversityJKIMSU,    Vol. 3, No. 2, July-Dec 2014CASE REPORTISSN 2231-4261Ó ÓAbstract:A 35 years old male came with complaints of low back ache radiating to right lower limb and is associated with tingling numbness and thin stream of urine since 1 year. Radiograph lumbo-scaral spine came out to be normal and thus MRI lumbo-sacral spine was done which  revealed  an  intramedullary  spinal  tumour. Subsequent CT scan was done for the patient. Consid-ering  the  tumour  characteristics,  diagnosis  of intramedullary dermoid was made.Keywords:  Dermoid  Cyst,  Intramedullary  Lesions, Spinal Tumours Introduction:Dermoids are benign inclusion tumours rarely pre-senting in adults. Typically they present in children in  the  region  of  the  conus  medullaris  and  are generally extramedullary. We present a very rare case of intramedullary dermoid cyst, presenting in a middle  aged  patient  causing  progressive  neuro-deficit. Our case is rare as demoids tumours consti-tute only for 1 – 2 % of intraspinal tumours [1].Case History:A 35 years old male came with complaints of low back ache radiating to right lower limb which was associated with tingling numbness and thin stream of urine since 1 year. It was not associated with weakness. There was no history of trauma. No history of any previous operative procedure.  On clinical examination, the skin over the neck and back was normal with no evidence of any sinus, hairy patch, or any cutaneous mark. Power in  right  lower  limb  was  4/5  and  left  was  5/5. Reflexes  were  normal.  Radiograph  of  lumbo-sacral spine was done which was normal.136Intramedullary Dermoid Cyst- A Rare Case Report1* 1 1 1 Aditi Gujarathi , Abhijit Patil , Naware S. S. , Kulkarni Vilas M.1Dept of Radio-diagnosis, Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune - (Maharashtra) India.For further evaluation, MR imaging examination of lumbo-sacral spine with screening of whole spine was performed with a 1.5 T unit (Magnetom Avanto , Siemens, Munich, Germany). The conus appeared  inconspicuous  with  a  large  lobulated long segment intramedullary solid – cystic lesion extending from L2 to S2 vertebrae. It measured approximately 13.8 cm (supero-inferior) x 1.94 cm (transverse). It was causing significant widen-ing of spinal canal without any scalloping of the vertebrae. The upper one third of the lesion was hyperintense on T1 (Fig. 1 & 4) and T2 (Fig. 2 & 5) weighted images and showed loss of signal in fat suppressed  images  (Fig.  3)  suggestive  of  fatty component. The middle one third and lower third were predominantly cystic, with the middle one third appearing hyperintense on T2WI (Fig. 2) and hypointense on T1WI (Fig. 1). Ill-defined hyper-intensities on T1WI (Fig. 1) images which appear-ed hypointense on T2WI (Fig. 2) and STIR (Fig. 3) as well as on GRE in the lower one third sugges-tive of hemorrhage within the cystic portion.There were well defined foci of blooming on GRE in the spinal canal at the level of S1-2 vertebrae suggestive of calcifications. A well defined focal fat signal was also seen at L5 level, probably in the intradural compartment. Spina bifida was seen at L5 level.There was no evidence of any obvious sinus tract or herniation of meninges or soft tissue abnormal-ity in this region.  MRI brain with whole spine screening was also done which was normal.Limited plain CT scan was performed on GE duo FII  scanner.  The  foci  of  blooming  within  the lesion which were seen on GRE images of MRI JKIMSU,    Vol. 3, No. 2, July-Dec 2014 Aditi Gujarathi et. al. Journal of Krishna Institute of Medical Sciences University Ó Ó 137Fig. 1: T1 Mid Sagittal MR Image of the Lumbar Spine Showing Fat in the Solid Component Appear-ing as Well Defined Hyperintensity in the Upper One Third, Cystic Area Appearing Hypointense in the Middle One Third and Hemorrhage within the Cystic Component Appearing as Ill-Defined Hyperintense SignalFig. 2: T2 Mid Sagittal MR Image of the Lumbar Spine Showing Fat in the Solid Component Appear-ing as Well Defined Hyperintensity in the Upper One Third, Cystic Area Appearing Hyperintense in the Middle One Third and Hemorrhage within the Cystic Component Appearing as Ill-Defined Hypointense SignalFig. 3: STIR Mid Sagittal MR Image of Lumbar Spine Showing Suppression of Fat Appearing as Hypointense Signal Predomi-nantly in the Upper One Third, Cystic Component Appearing Hyperintense in the Middle One Third and Hemorrhage Appear-ing as An Ill Defined Hypointense Signal in the Lower One ThirdFig. 4: T1 Axial MR Image through the Upper One Third of the Lesion Showing Hyperintense Fat Signal surrounding the Hypointense Subarachnoid SpaceFig. 5: T2 Axial MR Image through the Upper One Third of the Lesion Showing Hyperintense Fat Signal surrounding the Hyperintense Subarachnoid Space were  confirmed  to  be  due  to  intralesional calcifications which appeared hyperdense (Fig. 6). The hemorrhagic component seen on MRI was further confirmed on CT scan which showed HU values of 40-60 HU (Fig. 6). Our  patient  underwent  an  excisional  biopsy, which  confirmed  intramedullary  dermoid  cyst. The tumour could not be resected completely due to its tight adherence to the nerves. Hence the patient is being managed conservatively.Fig. 6: Mid Sagittal Reconstructed CT Image shows the Hypodense (100 to -110 HU) Fat in the Upper One Third, Cystic Component Appearing Isodense (10 to 15 HU) in the Middle One Third And Hyperdense (40 to 50 HU) in the Lower One ThirdDiscussionDermoids may be congenital or acquired in origin. These  tumours  constitute  1-2%  of  intraspinal tumours and are more frequently encountered in children  (10-17%)  [1].Congenital  lesions  are believed to result from inclusion of ectodermal cells during closure of the neural tube in the third to fifth weeks of fetal life. Acquired lesions can result  from  trauma  or  surgery.  The  common JKIMSU,    Vol. 3, No. 2, July-Dec 2014 Aditi Gujarathi et. al. Journal of Krishna Institute of Medical Sciences University Ó Ó 138locations of dermoid cyst are scalp, skull bones, intracranial,  and  intraspinal  mainly  intradural extramedullary; rarely intramedullary and associ-ated with other spine defects [2]. Intraspinal dermoids occur most frequently in the lumbosacral region (60%), only 5% in the cervical region [3]. Approximately 75% is extramedullary [2].Clinical Presentation:Symptoms are generally of late onset and nonspe-cific, manifesting commonly in childhood often leading to a delay in diagnosis.Young children and infants often have severe pain, motor regression, weakness. Symptoms depend on the location, extent of the tumour and are a result  of  the  space-occupying  lesion  causing compression  of  adjacent  structures  .Motor disturbances,  pain,  sensory  disturbances,  and urologic dysfunction frequently occur [4-6]. Dermoid  cysts  usually  present  themselves  in childhood. However, in this case, the patient had no associated developmental anomaly of the spine and thus the patient presented at a later age after he had developed significant symptoms.A dermoid cyst can rupture during surgery, after a trauma, or spontaneously. This can lead to spread of  contents  along  the  subarachnoid  space  and   ventricles causing aseptic chemical meningitis[7].Imaging Diagnosis:Radiography:  Vertebral  erosion,  spinal  canal widening.MRI:  The  signal  intensity  characteristics  are variable, depending on the cystic contents. The two major components of fluid and fat are appear-ing hyperintense on T-1weighted images being most consistent with the similar findings men-tioned by Do-Dai DD et al [8]. Areas of hyper-intensity are reflecting secretions of sebaceous glands and liquid lipid metabolites. Solid portions of  the  tumour  are  slightly  hypointense  to isointense  compared  with  spinal  cord.  On  T2-weighted images, the areas of T1 hyperintensity demonstrate relatively decreased signal intensity and the solid portions of the tumour are heteroge-neously hyperintense.Rupture  of  a  dermoid  may  result  in  free  T1-hyperintense fat drops within the intracranial and intraspinal subarachnoid space [6]. Fat droplets may also rarely be seen within a dilated central canal of the spinal cord as it was reported by De Maio PN et al [6].The differential diagnosis of spinal dermoid cysts includes  spinal  lipomas,  epidermoid  cyst  and myxopapillary ependymoma. MR distinguishes dermoid from lipoma by virtue of the non fatty component in the former.Fat hyperintensity is most specific for dermoid which is not seen in ependymomas and epiderm-oids. Also intrinsic Tl shortening permits differen-tiation of dermoid from epidermoid [6].1. Rapoport RJ, Flanders AE, Tartaglino LM. Intradural extramedullary causes of myelopathy. Semin Ultra-sound CT MR 1994; 15(3):189-225.2. Altay H, Kitiş O, Calli C, Yünten N. A spinal dermoid tumor that ruptured into the subarachnoidal space and syrinx cavity. Diagn Interv Radiol 2006; 12(4):171-173.3. Cha JG, Paik SH, Park JS, Park SJ, Kim DH, Lee HK. Ruptured  spinal  dermoid  cyst  with  disseminated intracranial  fat  droplets.  Br  J  Radiol  2006; 79(938):167-169.4. van Aalst J, Hoekstra F, Beuls EA, Cornips EM, Weber JW,  Sival  DA,  Creytens  DH,  Vles  JS.  Intraspinal dermoid and epidermoid tumors: report of 18 cases and reappraisal of the literature. Pediatr Neurosurg 2009; 45(4):281-290.5. KrishnaKK,  Agarwal  PA,  Agarwal  SI,  Jain  MM. References:*Author for Correspondence: Dr. Aditi Gujarathi, Department of Radio-diagnosis, D. Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune. Cell: 9822429444, Email: aditidoc89@gmail.comJKIMSU,    Vol. 3, No. 2, July-Dec 2014 Aditi Gujarathi et. al. Journal of Krishna Institute of Medical Sciences University Ó Ó 139CT Scan: Tumoural calcifications and fat hypo-density within a dermoid is more easily detected by CT [6].Diagnosis and Treatment: Although a diagnosis cannot be made without a tissue sample, certain neuroimaging  findings  are  characteristic  and useful in helping to distinguish inclusion cysts from other more common spinal lesions. MRI is the modality of choice for diagnosis of dermoid tumours [9].In addition, radical removal is, at times, precluded by the risk of neurological deficit in cases where tumour capsule adheres tightly to nervous tissue.Conclusion: The intramedullary location of a primary dermoid cyst involving the conus as well as cauda equina in an adult is rare and thus makes this case a very unique and rare entity. MRI is the best imaging tool  for  the  diagnosis.  CT  plays  an  important complementary role in identifying areas of fat and calcification.Dermoid  of  the  conus  medullaris.  J  Clin  Neurosci 2004; 11(7):796–797.6. De Maio PN, Mikulis DJ, Kiehl TR, Guha A. AIRP best cases  in  radiologic-pathologic  correlation:  Spinal conus  dermoid  cyst  with  lipid  dissemination.   Radiographics 2012; 32(4):1215-1221. 7. Sharma  M,  Mally  R,  Velho  V.  Ruptured  Conus Medullaris  Dermoid  Cyst  with  Fat  Droplets  in  the Central Canal. Asian Spine J  2013; 7(1):50-54 .8. Do-Dai  DD,  Brooks  MK,  Goldkamp  A,  Erbay  S, Bhadelia  RA.  Magnetic  resonance  imaging  of intramedullary spinal cord lesions: a pictorial review. Curr Probl Diagn Radiol 2010; 39(4):160–185.9. Calabro F, Capellini C, Jinkins JR. Rupture of spinal dermoid tumors with spread of fatty droplets in the cerebrospinal fluid pathways. Neuroradiology 2000; 42(8):572-579.

Intramedullary Dermoid Cyst- A Rare Case Report

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