|Year : 1975 | Volume
| Issue : 4 | Page : 21-24
SG Nag, Y Dayal, NN Sood, V Goswamy
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, A.I.I.M.S., New Delhi, India
S G Nag
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, A.I.I.M.S., New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Nag S G, Dayal Y, Sood N N, Goswamy V. Dictyoma. Indian J Ophthalmol 1975;23:21-4
Epithelial tumours of the ciliary body have been considered to be rare occurence in the past; only twenty cases have been reported till 1960. However, another thirty cases have been added during the last decade in the literature indicating that these are not as uncommon as believed to be. Better understanding and diagnostic aids available are possibly the factors responsible for this condition being diagnosed more often. In any case, these tumours do present problems in diagnosis as is evident in the case being reported by us. The tumour presented as uveitis with staphyloma and secondary glaucoma.
| Case report|| |
A 3˝ year old girl presented in the out patient department with parents, noticing a localised blackish swelling near the nasal side of the limbus of right eye associated with redness and pain of two months duration. The pain and redness had subsided following local application of some ointments for the first time, but had recurred. For the last 15 days, the parents noticed progressive increase in the limbal mass. There was no history of fever, cough, joint pains or trauma. Past and family history were non-contributory. Child was a full term, normal delivery and all milestones were normal.
Systemic examination revealed no abnormality except for a very few, small discrete mobile lymphnodes palpable in the upper cervical group on both sides. There was no preauricular lymph node enlargement. Local examination of left eye was normal and child could recognise objects at more than six metres distance.
Right eye revealed ciliary congestion on the nasal side of the limbus. A vertically oval blackish mass was seen underneath the conjunctiva measuring 8 mm. by 4 mm. with surrounding scleral thinning near the limbus between 2 and 3-30 `0' clock position. Prominent dilated conjunctival blood vessels were seen all around the mass (staphyloma). Anterior chamber revealed patches of organized, discrete greyish vegetations at 12, 1, 3 to 5 and 7 `0' clock positions on the iris at its mid periphery and extending to the angle region. Pupil was circular and dilated well with atropine ointment. Lens showed a few discrete opacities near the equator and was sub-luxated in upper nasal region. Child could see objects at more than 3 metres distance. Fundus showed deep glaucomatous cupping with nasal shift of blood vessels and tension was 38.9 mm Schiotz in the right eye. Corneal diameter was normal (11.5 mm x 12 mm/ B.E.). Swelling was transilluminant.
X-rays of orbit, optic, foramina, P.N.S. and chest were normal. Mountoux, Casoni's test, S.T.S. and Rose Waaller were all negative. A tentative diagnosis of anterior uveitis with deep scleritis, ciliary and intercalary staphyloma and secondary glaucoma was made in the right eye. Child was put on systemic and local steroids as well as atropine ointment. Three subconjunctival injections of hydrocortisone and mydricine were also given. As there was no improvement of the condition, a diagnostic aqueous puncture, removal of vegetation at 7 'o' clock and complete iridectomy between 12 and 1 `o' clock were done. The bacterial and fungal culture were negative. The aqueous obtained revealed highly anaplastic cells with pigmentation in a few of them. Iris tissue with the vegetations on histopathology revealed dictyoma. The eye was enucleated two days later with a wider excision of tenons, conjunctiva and part of medial and superior recti muscles adjacent to the mass. Post operative period was uneventful and sutures were removed on the tenth day.
Pathology report - Gross examination of the eye ball: Enucleated eye ball was partially collapsed measuring 22 mm. x 24 mm. x 23 mm. The cornea was normal but a vertically oval mass measuring 8 mm. x4 mm. with surrounding scleral thinning was seen near the limbus between 2 and 4 `o'clock position. Anterior chamber was normal but iris showed patches of organised greyish vegetations at 3,5 and 7 o'clock positions at the mid periphery. A section mark from 12 to 2 and a complete iridectomy in the same region was also seen. Lens was subluxated supero-nasally.
Cut section revealed tumour mass in the region of the ciliary body and was seen to extend anteriorly towards the iris. No mass was seen extending posteriorly. [Figure - 1][Figure - 2].
Tumour mass is formed by oval to cuboidal cells with oval nuclei. Cytoplasm is acidophillic. Mitosis is infrequent [Figure - 6]. The cells are arranged in clusters, sheets and cords enclosing cystic spaces [Figure - 3],[Figure - 4] or in long processes forming lacy net works [Figure - 5]. Very few of the cells show intracellular pigment.
| Discussion|| |
Tumours affecting the epithelium of ciliary body can best be divided into benign and malignant types. Malignant variety can further be differentiated into carcinomas and diktyomas, the former being derived from adult epithelium whereas the latter takes origin from embryonal epithelium. Badal and Lagrange were amongst the earliest to report this tumour followed by Fuchs, Imre and Rubino. Although it was Fuchs who coined the term diktyoma (from the Greek word diktyosnet) to emphasise the net like appearance of this tumour, however, the credit of recognizing its embryonic nature goes to Verhoeff who in addition pointed out the intimate relationship between retinoblastoma and diktyoma, both taking origin from embryonal retinal structures. These tumours were by and large thought to be relatively benign, very slowly growing and locally invasive in character. However, cases are on record which clearly pointed out its malignant characteristics. Imre and Rubino reported a case with extrabulbar spread. The same year Schepkalowa reported its recurrence in the orbit after enucleation. Yet another case with intra and extra cranial spread was reported by Malone. He also showed minute pulmonary metastasis. Tumour tends to spread more frequently on iris than on the retina as noticed in our case. Involvement of cornea and sclera has also been reported in 9 cases. Cases of diktyoma in India have been reported by Kesavachar and Junnarkar 7 and Nirankari et al.
Due to the peculiar site of the tumour, secondary glaucoma following blockage of the angle of the anterior chamber is an early complication in the disease process. This was also present in our case. Histologically the tumour may show large number of cystic spaces which are lined by single or multi-layered epithelium. Epithelium lining these spaces may be continuous with the non-pigmented epithelium of ciliary body. Various stages of developing retina may be seen. Connective tissue stroma may be absent or minimal.
The tumour mass may show numerous rows of nuclei, which when sectioned appear as layers of embryonic retina. The nuclei are elongated and are arranged in irregular rows. Mitotic figures can be seen at the margin of cell layers which correspond to the outer surface of the inner layer of the optic vesicle.
Islets of cartilage and areas of neuroglial tissues have been also reported in a number of cases showing the mutipularity of cells,,,,,,. Rosette formation may also be seen but blood vessels are not prominent. Regarding clinical picture it can be said that the symptoms mostly begin in early childhood; however, disease may be present right from birth. Few of the cases which have been reported at an advanced age presented either much bigger tumour or tumour with extensive invasion of surrounding structures. Sayed et al. reported a case at the age of 35 years. A surprising number of enucleated eyes show an intercalary staphyloma. This feature was clinically present in our case. Buphthalmos or even rupture of the globe have been reported,. The lesion may appear as a tumour from the ciliary body and spread to give rise to leukokoria and be mistaken for retinoblastoma. Although in view of its origin from embryonal retina, the term retinoblastoma of ciliary body appears more appropriate as it would make it comparable to other embryonic tumours like nephroblastoma and neuroblastoma, yet however, the term diktyoma has come to stay probably for two reasons. Firstly it avoids confusion from retinoblastoma, and secondly it points out one of the important features of this tumour i.e. net like appearance produced by the cystic spaces.
| Summary|| |
A case of embryonal medulloepithelioma (diktyoma) with varied clinical picture and typical histopathological features has been reported.
| References|| |
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[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6]