Uveal melanoma with extrascleral extension and systemic metastasis complicating into retinal detachment and cataract formation

Shivcharan L Chandravanshi, Sujata Lakhtakia, Mahesh K Rathore, Prem C Dwivedi, Jainendra S Rahud
Department of Ophthalmology, Gandhi Memorial Hospital, Rewa 486001 M.P, India

Correspondence Address:
Shivcharan L Chandravanshi
Department of Ophthalmology, S.S. Medical College & G. M. Hospital Rewa, M.P.- 486001
India

1

1. Authors have mentioned that magnetic resonance imaging (MRI) confirms the diagnosis of choroidal melanoma. At many times MRI is confusing in the diagnosis of choroidal lesions and gives only radiological clues whereas histopathological examination confirms the diagnosis. ^[2]
2. "Presenting as" is a common phrase in medical writing used to describe any unusual presentation of disease. Authors have highlighted uveal melanoma presenting as cataract and staphyloma. Staphyloma is a localized bulging of weak and thin outer tunic of the eyeball, lined by uveal tissue which shines through it. In their case, there is "almost a total loss of scleral fibers in the entire nasal quadrant" and tumor mass is visible through the scleral defect. Therefore it doesn't fit into the definition of staphyloma because there is neither scleral ectasia nor normal uveal tissue. Hence it is more likely a case of uveal melanoma with extrascleral extension. The authors have described anterior segment examination of right eye to be within normal limits but they have not mentioned its intraocular pressure (IOP). This is important since fundus findings of the same eye are suggestive of primary open angle glaucoma (POAG) and IOP of the left eye was 36 mm of Hg.
3. Cataract formation can occur in uveal melanoma due to lenticular infiltration by tumor cells which can be confirmed by histological examination of the lens. ^[3] Patient has fundus findings suggestive of POAG in the right eye and therefore there is a possibility of pre-existing bilateral POAG which could be another probable mechanism of cataract formation. The third possible mechanism may be secondary angle closure glaucoma secondary to neovascularization of iris and angle of anterior chamber.
4. Authors have speculated the origin of uveal melanoma in a pre-existing blind eye. But considering the six months duration of blindness and the slow-growing nature of malignant melanoma, it appears to be the reverse i.e. uveal melanoma leading to blindness. ^[4] Thus, advanced malignant melanoma leading to retinal detachment and cataract formation is more likely the cause of blindness in this case rather than origin of uveal melanoma in a blind eye.
5. Authors have mentioned "modified extended enucleation" under general anesthesia but they have neither described nor referenced the technique. An exhaustive English language PubMed search did not show any publication on "modified extended enucleation" technique. However, there are many modifications of enucleation. The "No-touch" technique modification is advocated by Fraunfelder and Wilson for enucleation of eyes that harbor intraocular malignancy. ^[5] Higher IOP secondary to manipulation of eyeball can lead to dissemination of tumor cells into the bloodstream and widespread metastasis. However, in the "no-touch technique, no direct pressure is exerted on the eyeball during enucleation and the tumor is frozen with intermittent cryo treatment to prevent metastatic spread.

References

1.	Khetan V, Gupta K, Mohan ER, Gopal L. Uveal melanoma presenting as cataract and staphyloma. Indian J Ophthalmol 2009;57:223-5.    [PUBMED]
2.	Davidorf FH, Chambers RB, Gresak P. False-positive magnetic resonance imaging of a metastatic carcinoma simulating a malignant melanoma. Ann Ophthalmol 1992;24:391-4.    [PUBMED]
3.	Shen SC, Yang CH, Lin HC, Chen SN. Aggressive small choroidal melanoma presenting as a dense cataract. J Cataract Refract Surg 2007;33:336-8.    [PUBMED]  [FULLTEXT]
4.	Char DH, Kroll S, Phillips TL. Uveal melanoma. Growth rate and prognosis. Arch Ophthalmol 1997;115:1014-8.    [PUBMED]  [FULLTEXT]
5.	Wilson RS, Fraunfelder FT. "No-touch" cryosurgical enucleation: a minimal trauma technique for eyes harboring intraocular malignancy. Ophthalmology 1978;85:1170-5.    [PUBMED]

This article has been cited by 1 Authorsæ reply Khetan, V., Gupta, K.E., Ravindra, M., Lingam, G. Indian Journal of Ophthalmology. 2010; 58(3): 257 [Pubmed]

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