Uveal melanoma is described as a mass with a large base and a smaller inner “collar-button” or “mushroom” shape, resulting from rupture of the choroidal tumor through Bruch’s membrane. Although there have been single case reports of collar-button–shaped masses in a wide variety of conditions,1–6 the vast majority of lesions with this shape are uveal melanomas.
We report a case of a secondary retinal vasoproliferative tumor that assumed a mushroom shape and provide confirmatory histopathology. To our knowledge and after a search in Medline/PubMed, this case represents the first report of a mushroom-shaped vasoproliferative tumor.
A 64-year-old man was referred to the Ocular Oncology Clinic at Bascom Palmer Eye Institute with a chief complaint of decreased vision. His ocular history was significant for a bilateral retinal detachment repair with cryotherapy and scleral buckling in the 1970s; redetachment repair in the left eye in 1993 with vitrectomy; and vitreous hemorrhage, which required vitrectomy in the left eye in 2010. On examination, best-corrected visual acuity was 20/20 in the right eye and counting fingers in the left eye. There was a left relative afferent pupillary defect. Intraocular pressures were 11 mm Hg in the right eye and 22 mm Hg in the left eye. Anterior segment examination revealed a dense cataract in the left eye. Dilated fundus examination of the right eye was unremarkable except for peripheral cryotherapy scars and a scleral buckle. There was no view to the fundus in the left eye due to vitreous hemorrhage.
Ultrasound was performed in the left eye using both contact B-scan and standardized A-scan. B-scan revealed moderately dense and dispersed vitreous opacities with peripheral membrane formation. There was a mushroom-shaped mass lesion at the 5-o’clock position anterior to the equator that appeared to be arising from the retina (Figure 1). The dimensions were 4.5 × 4.5 mm in base and 4.6 mm in apical height. On standardized A-scan, the lesion was irregularly structured, with medium to high internal reflectivity (Figure 2), and the presence of vascularity was noted. A repeat ultrasound study was performed 1 month later after initial presentation and no significant increase in the height or basal dimensions of the tumor were noted.
Figure 1. Ultrasound using contact B-scan. (A) Transverse B-scan shows a collar-button configuration of the vasoproliferative tumor of the fundus (arrow), consistent with a breakthrough Bruch’s membrane. (B) Longitudinal B-scan shows the radial extent of the tumor (arrow); in relation to the optic nerve (ON).
Figure 2. Standardized A-scan displays medium to high internal reflectivity (connected arrows).
The patient underwent pars plana vitrectomy and lensectomy with fine needle aspiration biopsy and cryotherapy. Intraoperatively, the mass was a classic secondary retinal vasoproliferative tumor with a red, round, circumscribed lesion without prominent feeder and draining vessels. Histopathology of the biopsy specimen disclosed a moderate amount of iron-stained lysed inflammatory cells; however, no definite tumor was identified. Postoperatively, the patient had recurrent vitreous hemorrhage and underwent a second pars plana vitrectomy with gas tamponade and endolaser. Later, the patient had recurrent vitreous hemorrhage, which had been stable for 10 months and visual acuity of hand motions.
Most uveal melanomas present with ultrasonographic features that allow for reliable and accurate differentiation. The major echographic characteristics of choroidal melanoma include mushroom or dome shape, regular structure, low to medium reflectivity, and vascularity.7 In the Collaborative Ocular Melanoma Study, the majority of tumors (88%) exhibited low to medium internal reflectivity, a mushroom shape, or both.8 There have been single case reports or small case series of other conditions simulating uveal melanoma presenting with a collar-button shape on B-scan, including choroidal metastases,1–3 choroidal hemangioma,4 retinoblastoma,5 and melanocytoma.6 However, to our knowledge, there has never been a report of a secondary vasoproliferative tumor presenting with a collar-button configuration.
Vasoproliferative tumor is a term first used by Shields et al.9 Previously, these lesions were often termed retinal capillary hemangiomas, angiomas, or peripheral retinal telangectasias.10 These lesions can be idiopathic or secondary, often associated with various ocular conditions such as retinitis pigmentosa, intermediate uveitis and other inflammatory and infectious conditions, familial vitreoretinopathy, Coats’ disease, and rhegmatogenous retinal detachment repair with cryotherapy as in our patient, who had previous retinal detachment repair with scleral buckle. They are typically located inferotemporally,9 as was our patient’s lesion. Some clinicians have speculated that this condition may be part of the proliferative vitreoretinopathy spectrum.11 Standardized echographic features reported to be characteristic for this condition include acoustic solidity, dome shape, medium to high internal reflectivity, and minimal internal vascularity.12
We report clinical, echographic, and histopathologic features of a secondary vasoproliferative tumor that assumed a mushroom shape mimicking a choroidal melanoma. Clinicians should be aware that this lesion should be on the differential diagnosis of a mushroom-shaped mass. Choroidal melanoma is traditionally a homogeneous cellular tumor with ultrasonographically low to medium internal reflectivity, as opposed to our case, which showed medium to high reflectivity. Clinical clues that may serve to differentiate it from uveal melanoma include preexisting ocular conditions such as retinitis pigmentosa, inflammatory conditions, or a history of retinal detachment repair, inferotemporal location near the ora serrata, and vitreous hemorrhage.
- : Shields JA, Shields CL, Brown GC, Eagle RC Jr, . Mushroom-shaped choroidal metastasis simulating a choroidal melanoma. Retina. 2002;22:810–813. doi:10.1097/00006982-200212000-00024 [CrossRef]
- : Read RW, Green RL, Rao NA. Metastatic adenocarcinoma with rupture through the Bruch membrane simulating a choroidal melanoma. Am J Ophthalmol. 2001;132:943–945. doi:10.1016/S0002-9394(01)01147-3 [CrossRef]
- : Ward SD, Byrne BJ, Kincaid MC, Mann ES. Ultrasonographic evidence of a mushroom-shaped choroidal metastasis. Am J Ophthalmol. 2000;130:681–682. doi:10.1016/S0002-9394(00)00604-8 [CrossRef]
- : Spraul CW, Kim D, Fineberg E, Grossniklaus HE. Mushroom-shaped choroidal hemangioma. Am J Ophthalmol. 1996;122:434–436.
- : Shields CL, Piccone MR, Shields JA, Eagle RC Jr, Singer M. Mushroom-shaped choroidal recurrence of retinoblastoma 25 years after therapy. Arch Ophthalmol. 2002;120:844–846.
- : Robertson DM, Campbell RJ, Salomão DR. Mushroom-shaped choroidal melanocytoma mimicking malignant melanoma. Arch Ophthalmol. 2002;120:82–85.
- : Ossoinig KC, Bigar F, Kaefring SL. Malignant melanoma of the choroid and ciliary body: a differential diagnosis in clinical echography. Bibl Ophthalmol. 1975;83:141–154.
- : Boldt HC, Byrne SF, Gilson MM, Collaborative Ocular Melanoma Study Group et al. Baseline echographic characteristics of tumors in eyes of patients enrolled in the Collaborative Ocular Melanoma Study: COMS report no. 29. Ophthalmology. 2008;115:1390–1397. doi:10.1016/j.ophtha.2007.12.015 [CrossRef]
- : Shields CL, Shields JA, Barrett J, De Potter P. Vasoproliferative tumors of the ocular fundus: classification and clinical manifestations in 103 patients. Arch Ophthalmol. 1995;113:615–623. doi:10.1001/archopht.1995.01100050083035 [CrossRef]
- : Campochiaro PA, Conway BP. Hemangiomalike masses of the retina. Arch Ophthalmol. 1988;106:1409–1413. doi:10.1001/archopht.1988.01060140573025 [CrossRef]
- : Rennie IG. Retinal vasoproliferative tumours. Eye (Lond). 2010;24:468–471. doi:10.1038/eye.2009.305 [CrossRef]
- : Piñeiro-Ces A, Blanco-Teijeiro MJ, Mera-Yáñez MP, Capeans-Tome C. Ultrasound diagnosis in vasoproliferative tumours of the ocular fundus [article in Spanish]. Arch Soc Esp Oftalmol. 2011;86:247–253.