Ultrasound biomicroscopy: role in diagnosis and management in 130 consecutive patients evaluated for anterior segment tumours

Abstract

Background/aim: Ultrasound biomicroscopy (UBM) is an important tool for assessing anterior segment pathology. This study sought to evaluate UBM in the management of anterior segment tumours.

Methods: Retrospective analysis of medical records of consecutive patients referred to the ocular oncology unit, University of California San Francisco (UCSF), for suspected anterior segment tumours from 1999 to 2004.

Results: 132 eyes from 130 patients were evaluated, including 55 uveal melanomas (UM), 21 iris naevi, 30 iris cysts, and 26 remaining lesions. Of the melanomas, 45 were also evaluated with conventional A/B-scan. There was 29% correspondence between the anatomical structures invaded by melanoma as identified by B-scan v disease extent defined by UBM. Ciliary body and peripheral iris involvement by melanomas was significantly more frequently observed by UBM than B-scan. Seven of 30 benign cysts were diagnosed as cystic before UBM evaluation. In three cases, neuroepithelial cysts were associated with intercurrent pathology including iris naevus (n = 2) and ciliary body melanoma (n = 1). Two ciliary body melanomas showed cavitation, including one patient with a pseudocyst. Histopathological correlation was possible in six cases.

Conclusion: UBM is an indispensable tool for the management of anterior segment tumours. This study demonstrates the superiority of UBM v conventional B-scan for the precise localisation of uveal melanoma, especially involving the ciliary body and peripheral iris.

Figure 1

Neuroepithelial cyst and naevus associated with cyst. (A) Slit lamp photograph, right eye, of pigmented iris naevus. Note mild pupil distortion. (B) Higher power showing elevation of the lesion in (A). (C) UBM of the naevus in (A) and (B) demonstrates an associated thin walled neuroepithelial cyst (c, cyst, n, naevus). (D) UBM of a typical peripheral neuroepithelial cyst with a thin cyst wall and anechoic centre (c, cyst). Note angle closure is present in the region of the cyst. (E) Slit lamp photograph, left eye, of a ciliary body melanoma (*) with an associated large neuroepithelial cyst. The cyst is visible at the pupil (arrow). (F) UBM of the patient in (E). A large cyst with features resembling a primary neuroepithelial cyst including thin, highly reflective cyst wall (arrows) is associated with the ciliary body melanoma (not shown).

Figure 2

Iridociliary melanoma right eye (A–D). (A) Slit lamp photograph demonstrating an amelanotic mass with prominent intrinsic vasculature. This lesion showed growth tendency on serial UBM. Note marked pupil distortion. (B) B-scan shows a markedly thickened peripheral iris (arrow). (C) UBM iris/iris root/ciliary body shows involvement by a solid mass with variable internal reflectivity. (D) UBM higher power. The mass invades the iris root and minimally involves the pars plicata of the ciliary body, evidenced by the area of reduced reflectivity compared to the surrounding tissues. UBM proved very useful intraoperatively in defining the extent of ciliary body involvement in this case, as the amelanotic nature of the lesion precluded accurate assessment by transillumination. (E) Another patient with iris melanoma. Note distortion of the posterior iris plane by tumour.

Figure 3

Iridociliary melanoma right eye. (A) Slit lamp photograph showing characteristic convex ciliary body tumour invading and displacing iris stroma. (B) B-scan ultrasound shows a solid mass with heterogeneous internal reflectivity. (C) UBM demonstrates that the tumour in (B), has internal cavitation (M, melanoma; C, cavitation). (D) UBM, right eye, of a patient with a pigmented mass noted on routine glaucoma screening examination. The mass is solid and has low moderate internal reflectivity. The maximal diameter is 1.7 mm. Note early invasion of the iris root and angle evidenced by reduced reflectivity compared to surrounding structures. (E) Ciliary body melanoma from another patient demonstrates prominent internal cavitation with pseudocyst formation. This lesion appeared to be cystic on conventional B-scan. (F) UBM of the patient in (E), however, revealed the solid component and thickened wall with medium reflectivity.