The objectives of this study were to determine the incidence of lumbocutaneous stimgmata (LCS) and to outline the optimal use of sonographic screening for spinal dysrraphism (SD). The first phase was a prospective study from July 1993 to November 1996, during which 137 infants with LCS were directly referred to the radiologist to rule out SD. In the second phase of the study, 1449 consecutive births (between January 1 and November 1, 1996) were clinically inspected for LCS. Seventy infants (5.3%) were found to have LCS. The combined study population consisted of 207 infants. The size, shape, placement, distance from the anus, and associated skin findings (hairy patches, hemangiomas, nevi) were documented. A lumbosacral spine sonographic evaluation was performed on each study patient for SD. A total of 160 had simple dimples (defined as <0.5cm midline placement within 2.5cm of the anus), but were not found to have SD. The remaining 47 had a total of 56 LCS. Sixteen of these infants (11 females, 5 males) were found to have SD by ultrasound (PPV 34%). These 56 LCS were classified into four groups (as described in the table below) based on their physical findings.

Table 1
Full size table

In this population, the incidence of LCS was 5.3% of all births. Routine screening of simple sacral dimples located within 2.5 cm from the anus is not recommended, whereas sonographic screening is warranted for atypical dimples and LCS, defined as large (>0.5cm), high on the back (>2.5cm from the anus) and in combination with other lesions.

University of Kentucky Medical Center Research Grant