Choroidal neurilemmoma--an unusual clinical misdiagnosis

Intraocular schwannoma: case series of 28 patients and literature review

PURPOSE

Intraocular schwannoma is a rare tumour, which is often misdiagnosed. We presented the demographics and clinical characteristics of patients with intraocular schwannoma.

METHODS

Retrospective case series were collected between May 2005 and July 2021 in Beijing Tongren Hospital.

RESULTS

A total of 28 patients were diagnosed with intraocular schwannoma on histopathological examination of surgical specimen. The median age was 39 years (range: 12-64). Fourteen patients were female and 14 were male. Among the all subjects, 21/28 patients (75.0%) presented as visual loss, and 3/28 patients (10.7%) had visual field loss. Intraocular schwannoma presented as nonpigmented mass in the ciliary body in 12/28 cases (42.9%), in the choroid in 9/28 cases (32.1%), and in ciliochoroid in 7/28 cases (25.0%). Intraocular schwannoma was often clinically misdiagnosed as uveal melanoma, which occurred in 16/28 patients (57.1%). Tumour excision with pars plana vitrectomy was performed for all included patients. Endoresection with lens removal was performed for tumours in the choroid, while transscleral resection was performed for tumours located in ciliary body or ciliochoroid. Increased light transmission was detected in 12/28 cases (42.9%). In the consecutive follow-up (median: 73 months, range: 7-193 months), no cases of recurrence or metastatic disease were detected.

CONCLUSIONS

Intraocular schwannoma is a rare benign tumour. It usually presents as nonpigmented mass, which can easily be misdiagnosed as nonpigmented uveal melanoma.

Accuracy of presumed uveal melanoma diagnosis before alternative therapy

AIMS/BACKGROUND

This study was performed to ascertain the diagnostic accuracy rate of non-invasive tests in patients with presumed uveal melanomas scheduled to be treated with either irradiation or cyclochoroidectomy.

METHODS

One hundred consecutive patients who had non-invasive tests followed by fine needle aspiration biopsy (FNAB) as prior alternative treatment were analysed retrospectively.

RESULTS

In 86 cases the diagnosis of uveal melanoma was confirmed on FNAB. In five cases false negative results were obtained. In nine patients a diagnosis other than a uveal melanoma was made on the basis of cytopathology. No significant morbidity and no evidence of tumour spread occurred.

CONCLUSION

In presumed uveal melanomas eligible for treatment with alternative therapies, the diagnostic accuracy of non-invasive tests is not as good as with larger tumours that require enucleation. Fine needle aspiration biopsy data resulted in correct management of 9% of cases that were thought to have uveal melanomas on non-invasive tests, but had other lesions on cytopathological evaluation.

Schwannoma of the ciliary body treated by block excision

A 26-year-old man developed a non-pigmented ciliary body tumour of his right eye. A 7 mm block excision and tectonic corneoscleral graft were performed. The excised tissue was studied using histopathological, immunohistochemical, and electron microscopic techniques. The tumour revealed characteristic features of a Schwann cell neoplasm including Antoni A and B patterns, acid mucopolysaccharides, S-100, and vimentin positivity, and--by electron microscopy--Luse bodies. It was classified as a schwannoma. Although rare, schwannoma should be included in the clinical differential diagnosis of non-pigmented ciliary body tumours. Local excision should be considered to avoid over-treatment by enucleation.

Neurilemmoma of the anterior ethmoidal nerve encroaching upon the nasolacrimal duct

The clinical, light microscopic, ultrastructural, and immunohistologic findings of a neurilemmoma encroaching upon the nasolacrimal duct are presented. This is the first reported case of this rare tumour of the nasolacrimal duct where the diagnosis has been confirmed by electron microscopy and immunohistochemical techniques.

Ciliary body neurilemoma recurring after 15 years

A 57-year-old white female presented with a recurring neurilemoma (benign solitary schwannoma) of the ciliary body 15 years after the primary modified iridocyclectomy. As neurilemoma are encapsulated, successful "tumorectomy" was twice accomplished with total anatomical and functional preservation of the globe. The pathological diagnosis of spindle cell tumors of the uvea is discussed.

Anterior uveal neurilemmoma--a rare neoplasm simulating malignant melanoma

A 30-year-old woman presented with dilated episcleral vessels in the right eye which were found to be associated with an underlying ciliary body tumour. Contact lens examination, transpupillary transillumination, ultrasonography, computerised tomography, magnetic resonance imaging, and fine needle aspiration biopsy produced apparently conflicting and inconclusive results, and the eye was enucleated. Light and electron microscopy showed the lesion to be a neurilemmoma (schwannoma), of which very few cases have been reported. The clinical and pathological features are described and discussed.

The neural crest origin of uveal melanomas

On the basis of two cases the relation between 'neurogenic' tumours (neurinomas, neurilemmomas, Schwannomas, neurofibromas) and malignant melanomas of the uvea is discussed with emphasis on the close association of both groups of neoplasms with the ciliary nerves. The great histopathological diversity between different cases of melanoma as well as within individual cases is also pointed out. On histological and cytological criteria it may be difficult to differentiate between the 'neurogenic' tumours and the highly differentiated, spindle cell variants of the melanomas. Since all these tumours are derived from the neural crest, they might be grouped under one common heading. It is postulated that 'neurogenic' tumours have been overdiagnosed to the disadvantage of the highly differentiated spindle cell melanomas.

Neurilemmoma of the ciliary body: report of a case

A case of ciliary body neurilemmoma is described. This neoplasm is extremely rare in the uveal tract and has been reported only once in the ciliary body. After extensive clinical studies of the rapidly growing tumour enucleation was performed. Subsequent histological examination showed typical features of highly vascular benign neurilemmoma. The main clinical and pathological features are reported and diagnostic problems are discussed.

Benign peripheral nerve tumor of the choroid: a clinicopathologic correlation and review of the literature

A 30-year-old white male was found to have a small, nonpigmented choroidal tumor in the temporal portion of the macula in the left eye. A diagnosis of choroidal melanoma was made, based on the clinical appearance, fluorescein angiography, ultrasonography, and growth of the tumor. In spite of treatment with a cobalt plaque, the tumor continued to grow, and the eye was enucleated. Histopathologic study revealed a benign peripheral nerve tumor of the choroid, presumably a neurilemoma (Schwannoma). A correlation between clinical features, fluorescein angiography, ultrasonography, light microscopy, and electron microscopy is presented, and the literature on solitary peripheral nerve tumors of the uveal tract is reviewed.