CASE- REPORT and mediastinal windows demon- strated the CT angiogram sign. I Attenuation of the lobe was heteroge- neous.' Multiple air bronchograms were seen" There was dilatation, stretching, sweeping, widening of the angle and crowding of bronchi .1 A pleural effusion was noted. Discussion Our patient had specific signs of bronchoalveolar consolidation which include squeezing, stretching and sweeping patent air bronchograms within the consolidated lung.' The 'crazy paving' pattern is due to thick- ening of the interlobular septae.' All these changes, due to unique lepidic growth of the tumour were also noted.' Our patient did not have satellite lesions or bulging tissues, which increase the likelihood of bron- choalveolar carcinoma (BAC). Other absent signs were pseudocavitation, air fluid level in cavities and marginal enhancement. 4,5 Although the CT angiogram sign was present it is also seen in pneumo- nia, and is therefore nonspecific." References 1. Akata S, Fukushima A, Kakizaki D, Ase K, Amino S. cr scanning of bronchioalveolar car- cinoma: specific appearances. Lung Cancer 1995; 12: 221-230. 2. Irn J, Han MC, Yu EJ, et al. Lobar bronchioalve- olar carcinoma: 'angiogram sign' on cr scans. Radiology 1990; 176: 749-753. 3. Zeuthlin N, Lasser EC, Rigler LG. Bronchographic abnormalities in alveolar cell carcinoma of the lung. Dis Chest 1954; 25: 542- 549. 4. Im J, Cho Bl, Park JH, et al. cr findings oflobar bronchioalveolar carcinoma. J Comput Assist Tomogr 1986; 10: 320-322. 5. Manning JT Jr, Spjut HJ, Tschen JA. Bronchioloalveolar carcinoma: the significance of histopathologic types. Cancer 1984; 54: 525- 534. 6. Barsky SH, Grossman DA, Ho J, Holmes EC. The multifocality of bronchioloalveolar lung carcinoma: evidence and implications of a mul- ticlonal origin. Mod Patho11994; 7: 633-640. Occult spinal dysraphism L D R Tsatsi MB ChB, FCRad D)SA Department of Diagnostic Radiology Medical University of Southern Africa B Okoli MBBS,MMed Department of Neurosurgery Medical University of Southern Africa Case presentation A 2-month-old male patient pre- sented to our outpatient's department with a diffuse back swelling. The child is the fifth in a family with no history of congenital abnormalities. The pregnancy went full term and was a normal vaginal delivery. A diffuse swelling was noted in the midline in the lumbar region. The mass was covered with normal skin, with no discolouration, hair, sinus or ulceration. It had a soft, fatty feel on palpation. There was no neurological dys- function. Plain film X-rays of the spine demonstrated spina bifida involving the whole spine with sparing of only TI2, Ll, L2 and L3 (Figs 1 and 2). The defects were more pro- nounced in the upper cervical and sacral areas. The spinous processes in the thoracic and lumbar areas were visualised though they were not fused. A CT scan reconstruction of the 26 SA JOURNAL OF RADIOLOGY • September 2002 Fig. 1 AP spinal X-ray of the cervical and thoracic spine showing the extensive spina bifida involving both regions. whole spine demonstrated the spina bifida (Figs 3 and 4). MR! findings showed a normal cord from the cervical to the sacral level. CASE REPORT Fig. 2. AP spinal X-ray of the lumbo-sacral region demonstfating the spina bifida in the sacral region. Fig. 3. CAT scan reconstruction of the spine demonstrating the spina blfida in the cervical and thofacic region. A CT scan of the brain was not performed. To the best of our knowledge such an extensive occult spinal dysraphism has not been reported in the literature. Discussion Simple occult spinal dysraphism is often an incidental finding caused by an incomplete closure of the spinal arches of the posterior elements of the Fig. 4. CAT scan reconstruction of the sacrum demonstrating the open spinal canal In this region. It occurs in 5 - 36% of the popula- tion and is often asymptomatic. This report illustrates the presen- tation and radiological findings in a 2- month-old boy. Spinal dysraphism is explained by two theories. The first theory, called the neurulation defect theory, holds that there is a primary failure of clo- sure of the neural folds. This occurs between days 18 and 21 of gestation. The other theory, called the post neu- rulation theory, postulates that there is a breakdown in the posterior ele- ments of the fused tube.' Some authors report a slight female predominance while others report equal sex distribution." There is a lower risk among blacks com- pared with the Caucasian population and the risk in the general population is about 5 - 36%.4 The clinical pointers to the exis- tence of an occult spinal dysraphism in the postnatal life are classical skin markers, which occur in 75 - 83% of patients. These include dimples, sinus tracts, hypertrichosis and capillary haemangiomas. There can be associated occult vertebrae. intraspinal lesions such as epidermoid 27 SA JOU RNAL OF RADIOLOGY • September 2002 and dermoid tumours, lipomas, diastematomyelia, dural bands and tethered spinal cord,' Forty-five per cent of the lesions occur over the thoracolumbar junc- tion, 20% over the lumbar segment, 20% over the lumbosacral junction and 10% over the sacral region. Patients with occult spinal dys- raphism of the simple type are usual- ly asymptotic compared with the symptomatic ones whose clinical pre- sentation is as a result of traction from a tethered cord or pressure effect from the associated lesions or a combina- tion of both. These children present clinically at the time they start to walk with a com- bination of neurological problems like sphincter disturbances, neurological defects like motor weakness and sen- sory loss, and orthopaedic abnormal- ities like foot and ankle deformities. The classic roentgenographic appearance is a widened spinal canal with defects in the spinous process and a variable portion of the lamina. CT scan and MR! will elucidate the other associated intraspinal lesions. Treatment is surgical and is reserved for patients with sympto- matic occult spinal dysraphism. References 1. Lemire RI, Warkany I. Normal development of the central nervous system. Correlation with selected malformation. In: Beckwith B, ed. Pediatric Neurosurgery: Surgery of the Developing Nervous System. New York: Grune and Stratton, 1982: 1 - 22. 2. Schmalohi D. Spinal dysraphism. In: Palmer ID, ed. Manual of Neurosurgery. London: Churchill Livingstone, 1996: 646 - 651. 3. Humphreys RP. Spinal dysraphism. Neurosurgery. New York: Me Graw-Hill, 1996: 3453 - 3463 4. Horwood Nash DC, Fitz CR. Neuroradiology in Infants and Children. St Louis: Mosby, 1976. 5. Bajpai M, Kataria R, Gupta DK, Agarwala S. Occult spinal dysraphism. Indian J Pediatr 1997 64: suppl, 62 - 67.