Ultrasound detection of posterior scleral bowing in young patients with choroidal melanoma.
BACKGROUND
In evaluating young patients with choroidal melanomas, which are uncommon in people less than 30 years old, we noted that some had the ultrasound appearance of posterior scleral bowing. The purpose of this study was to determine the incidence of posterior scleral bowing in young patients with choroidal melanoma.


METHODS
We reviewed the ultrasonograms of 24 patients less than 30 years of age (mean age 25 years [standard deviation (SD) 4.7 years]) who presented to an ocular oncology service in Toronto between May 1984 and May 1997. In all cases the diagnosis was choroidal melanoma. Histologic specimens were available in six cases.


RESULTS
Scleral indentation posterior to the normal curvature of the globe was identified in 14 patients (58%). These patients had a mean tumour height of 4.4 mm (SD 2.0 mm) and mean tumour diameter of 9.5 mm (SD 2.9 mm). In the 10 patients with no scleral bowing the mean tumour height was 5.7 mm (SD 3.1 mm) and mean tumour diameter 11.5 mm (SD 3.8 mm). Pathological study (results available in nine cases in the scleral bowing group and four cases in the group without bowing) showed that all the tumours in the former group and three of those in the latter group were of the more indolent cell types, either mixed with predominantly spindle cells, or spindle cell. The six patients with histologic specimens were all in the scleral bowing group. The histologic features supported the ultrasound finding of posterior scleral bowing. No transscleral invasion occurred over the tumour region.


CONCLUSIONS
Posterior bowing of the sclera at the tumour site was observed in over half of young patients with choroidal melanoma. This phenomenon can be detected by ultrasonography and has a different appearance from that of choroidal excavation.
Cham
M C
MC
Department of Ophthalmology, Ontario Cancer Institute, Princess Margaret Hospital, University of Toronto.
Pavlin
C J
CJ
D000293:Adolescent; D000328:Adult; D002830:Choroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology; D011379:Prognosis; D012189:Retrospective Studies; D012590:Sclera / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index; D014463:Ultrasonography