Cytologic features of chordoid meningioma. A case report

BACKGROUND

Chordoid meningioma is a rare subtype of meningioma characterized by myxoid matrices deposited among epithelioid or vacuolated tumor cells and infiltrates of inflammatory cells, and its cytologic features have rarely been reported.

CASE

A 57-year-old man with a history of headache and visual disturbance presented with a tumor in the suprasellar region. Intraoperative touch smear cytology of the tumor disclosed a cord-like arrangement of polygonal tumor cells occasionally containing intranuclear inclusions. Furthermore, periodic acid-Schiff-positive, mucinous matrices were deposited among the tumor cells. Also, infiltrates of lymphocytes and plasma cells were noted. Histologic, immunohistochemical and ultrastructural examination confirmed the diagnosis of chordoid meningioma.

CONCLUSION

Intraoperative smear cytology in a case of chordoid meningioma showed distinctive cytologic features suggestive of the histologic patterns. The cytologic features, together with a histologic examination, are useful for its diagnosis.

Clinicopathological correlation of polypoidal choroidal vasculopathy revealed by ultrastructural study

AIMS

To describe the clinical and histopathological findings in a patient with polypoidal choroidal vasculopathy.

METHODS

A 76 year old Japanese man had a discrete, orange-red lesion of 1 disc diameter in the macula, with the fluorescein and indocyanine green angiographic and optical coherence tomographic findings compatible with polypoidal choroidal vasculopathy. He underwent a surgical removal of the macular lesion, followed by light and electron microscopic examinations.

RESULTS

The histopathological examination revealed that the specimen consisted of degenerated retinal pigment epithelium-Bruch's membrane-choriocapillaris complex and inner choroid. A tortuous, unusually dilated venule was present adjacent to an arteriole with marked sclerotic changes, appearing to form arteriovenous crossing. These vessels seemed to represent native inner choroidal vessels, and had haemorrhage per diapedesis. Blood cells and fibrin filled the lumina of the vessels and accumulated in the extravascular spaces, indicating vascular stasis.

CONCLUSION

Hyperpermeability and haemorrhage due to stasis of a dilated venule and an arteriole involved by sclerosis at the site where they cross in the inner choroid might cause oedema and degeneration of the tissue. Voluminous accumulation of blood cells and fibrin might generate elevation of tissue pressure sufficient to displace the weakened lesion anteriorly. The result suggests that the polypoidal vessels in this case represent abnormality in the inner choroidal vasculature.

Additional cell damage after transpupillary thermotherapy in choroidal malignant melanoma

The aim of this study was to evaluate the effectiveness of transpupillary thermotherapy (TTT) in generating tumour necrosis by light and electron microscopy, as well as to evaluate additional cell damage in the area directly adherent to the necrotic zone. Four eyes of four patients diagnosed with intraocular malignant melanoma of the uvea were treated experimentally with diode laser TTT. In all cases a standard technique was used. All eyes were enucleated: one eye the day after TTT, two eyes 2 days after TTT, and one eye 6 weeks after TTT. Immediately after enucleation the eyes were immersed in standard Karnovsky's fixative with cocodylate buffer and prepared for light and electron microscopy. In the treated area of all four melanomas we found a dense band of necrotic tissue (zone A) consisting of an amorphous mass of dead cells sharply demarcated from the rest of the neoplastic tissue. Next to this zone was a more eosinophilic and also sharply demarcated band (zone B) that consisted of similar but less intensive changes. In the next band (zone C), marked injury to the cellular membrane and subcellular structures were seen on electron microscopy. The next band (zone D) consisted of changes mainly observed only within the cytoplasm of neoplastic cells and significantly less intensive than those in zone C. Outside zone D tumour cells that were normal in appearance were seen. No scleral alterations induced by heat were found. We concluded that after TTT the cytotoxic effect gradually decreases in proportion to the distance from the central point of the diode laser spot, with additional cell damage in the area adjacent to the necrotic zone. The interval between TTT and enucleation had no influence on the histological results.

Choroidal schwannoma: immunohistochemical and electron-microscopic study

Schwannoma (neurilemoma) arising from the ciliary body and choroid is a rare form of intraocular tumor and usually misdiagnosed clinically as amelanotic melanoma. This case report describes a 73-year-old woman who developed a large nonpigmented intraocular tumor of the choroid in the left eye and underwent enucleation with a clinical diagnosis of malignant melanoma. The tumor consisted of spindle-shaped cells with an indefinite cytoplasm and twisted nuclei, which had positive immunoreactivity for S-100 protein, vimentin, glial fibrillary acidic protein and neural cell adhesion molecule. A continuous basal lamina encompassing the tumor cells was demonstrated by immunostaining for laminin and type IV collagen. Ultrastructurally, tumor cells with scant organelles had delicate cytoplasmic processes apposing each other, all indicative of Schwann cell origin. In reexamination of fluorescein angiograms, ultrasonograms and magnetic resonance images, no findings were incompatible with a diagnosis of choroidal melanoma. Histopathological studies showed that the tumor was a schwannoma. At present, we do not have a benchmark for the clinical diagnosis of intraocular schwannoma.

Effect of dacarbazine (DTIC) on cultures from malignant melanoma of the choroid: an immunohistochemical and electron microscopic study

INTRODUCTION

Dacarbazine (DTIC) is a very effective chemotherapeutic agent used in the treatment of cutaneous melanoma; it also could have a potential therapeutic value as an antimetastatic agent in the treatment of choroidal melanoma.

OBJECTIVE

To study the HMB-45 and S100 protein expression in choroidal melanoma cultures with and without DTIC, and compare the immunohistochemical and electron microscopic changes in both groups.

METHODS

Five- and seven-day cultures of choroidal melanoma (n = 21) were cultivated in diffusion chambers. The cultures were divided in two groups: I group (control group)--the cells were grown in 199-medium; II group--the cells were in 199-medium supplemented with 0.03 mg/ml of DTIC. Immunohistochemical studies were performed with paraffin-embedded material of the cultures by the avidin-biotin-alkaline phosphatase technique. Araldit-embedded material was studied by electron microscopy.

RESULTS

The expression of HMB-45 and S100 protein in the cultures with DTIC ranged from slightly positive to negative. The tumor cells were severely damaged. Electron microscopy in this group showed presence only of cellular fragments. In the DTIC-free group the HMB-45 and S100 expressions were strongly positive. There were no electron microscopic evidence of cellular death.

CONCLUSION

DTIC suppresses the growth of choroidal melanoma in vitro. These results indicate that further studies are warranted to elucidate the effect of DTIC in vivo.

Benign fibrous histiocytoma of the choroid

Benign fibrous histiocytoma (BFH) is a common soft tissue tumour. However, its occurrence in the orbit was not well recognised in the past. It is only in recent years that this condition has become more frequently diagnosed. Now, it is believed to be the commonest mesenchymal tumour of the orbit in adults. Its occurrence in the uveal tract is, however, exceedingly rare. Only one case of presumed fibrous histiocytoma of the choroid has been reported in the literature. We report herein a case of BFH of the choroid in the left eye of a Chinese woman. The patient presented with a huge but asymptomatic raised choroidal mass. Results of choroidal biopsy showed no sign of malignancy but definitive diagnosis could not be made. Enucleation was finally performed. The diagnosis was made on detailed evaluation of the results of the immunohistochemical staining and the ultrastructural findings. The patient remained well at the latest follow-up, which was 33 months after enucleation. Although BFH of the choroid is vary rare, its benign nature and the availability of choroidal biopsy for tissue diagnosis make it important to include this as one of the differential diagnoses for amelanotic choroidal mass.

Mean of the ten largest nucleoli, microcirculation architecture, and prognosis of ciliochoroidal melanomas

BACKGROUND

Cytomorphometric measurements and the architecture of the microcirculation in tissue sections of eyes removed for ciliary body or choroidal melanomas have been identified independently as prognostically significant factors for survival. The relative significance of these two histologic features is addressed in this study.

METHODS

The same 234 cases used to assess the prognostic significance of the microcirculatory patterns of choroidal and ciliary body melanomas were examined by two independent observers who measured the largest diameter of melanoma cell nucleoli from digitized images at a high magnification (x 3000) using the laser scanning confocal microscope. The mean of the ten largest nucleoli was calculated for each tumor according to previously published methods. Intraobserver and interobserver reproducibility was assessed for these measurements. Several Cox multiple regression models were constructed which included this cytomorphometric variable with and without the inclusion of the microcirculatory patterns.

RESULTS

There is a high degree of intraobserver reproducibility but only a weak degree of interobserver reproducibility in measuring the mean of the ten largest nucleoli. Using multiple Cox regression models, the mean of the ten largest nucleoli from each observer failed to exert any effect on outcome after enucleation, regardless of whether the presence of networks of closed vascular loops was considered in the statistical formulation. The presence of networks of closed vascular loops was found to be the most statistically dominant histologic prognostic characteristic.

CONCLUSION

The authors have not been able to confirm the use of the mean of the ten largest nucleoli as a significant prognostic factor in the outcome of patients whose eyes have been removed for ciliary body or choroidal melanomas. Further investigation of this cytomorphometric technique by other laboratories is warranted.

Melanotic schwannoma of the choroid. Immunohistochemistry and electron microscopic observations

PURPOSE

The purpose of this article is to describe what is probably the first reported case of a melanotic schwannoma of the choroid and to discuss the clinical and histopathologic features that serve to differentiate this rare intraocular tumor from a malignant melanoma of the choroid.

PATIENT AND METHODS

A 21-year-old woman underwent enucleation of the right eye for a slowly enlarging pigmented choroidal mass that was associated with ipsilateral blindness. The tumor was studied by light microscopy, immunohistochemistry, and electron microscopy.

FINDINGS

The tumor was composed of fascicles and whorls of pigmented and nonpigmented plump spindle cells that had light microscopic features of a schwannoma. The tumor cells showed immunoreactivity to S-100 protein and HMB-45. Electron microscopy showed cytoplasmic processes surrounded by a continuous basement membrane and abundant extracellular collagen. The pigmented spindle-shaped cells contained melanosomes in different stages of melanogenesis. The findings were compatible with a melanotic schwannoma.

CONCLUSION

Melanotic schwannoma has been reported in soft tissues, peripheral nerves, and in the orbit. To the authors' knowledge, this is the first report of a melanotic schwannoma of the choroid. This extremely rare pigmented choroidal tumor may be very difficult to differentiate clinically from choroidal melanoma.

Possibilities and limitations of radioimmunoscintigraphy and conventional diagnostic modalities in choroidal melanoma

A prospective clinical study to assess the value of immunoscintigraphy with a monoclonal antibody (MoAb) against high molecular weight melanoma associated antigen (225.28S) was performed in 43 patients with choroidal melanoma; in six patients with a lesion suspected of being choroidal melanoma, and in seven patients with a benign lesion simulating a choroidal melanoma. The results of immunoscintigraphy in choroidal melanoma were compared with results of conventional diagnostic modalities like ultrasonography and fluorescein angiography. Planar scintigraphy showed a detection rate of 49% which is comparable with other studies. The detection with scintigraphy was correlated to the size of the choroidal melanoma. The use of single photon computed tomography did not increase the sensitivity of immunoscintigraphy. Ultrasonography yielded a correct diagnosis in 37 of 42 melanomas (88%). With fluorescein angiography a correct diagnosis was obtained in 11 of 30 melanomas (36.6%). The value of immunoscintigraphy with MoAb 225.28S in small choroidal melanomas is limited; its reliability increases in large tumours. Immunohistochemistry with MoAb 225.28S showed antigen expression in 95% of the stained tissue specimens of choroidal melanoma.

[The ultramicroscopic aspects in malignant choroidal melanoma]

The survey focuses on the observation using the electronic microscope of two cases of uveal malignant melanoma. The ultrastructure of the cellular population which from this type of malignant tumour was followed, mentioning both the common and the particular aspects. The nuclear and nucleolar modifications, indicating an increase degree of atypia for the epithelioid cells compared with the fusiform cells, were observed. Some aspects of the abnormal tumoural cells were also emphasized. We noticed in the structure of the tumours, besides the tumoural cells, another structure of non-tumoural macrophage and reticular cells, and we described their ultrastructure.

[The characteristics of the nucleolar organizer in tumors of the choroid of the eye]

26 intraocular melanomas were studied histologically, ultrastructurally and morphometrically. For the first time the impregnation method was used for visualization of the nucleolar organizer (NO) in the cells of eye tumors using silver salts on the deparaffined sections. The efficiency and reliability of this method in the determination of the degree of malignancy of intraocular melanomas are demonstrated. A correlation existed between long-term postoperative results and the nucleolar organizer index (NO number/number of nuclei). The method can be practiced in any pathohistologic laboratory.

Significance, specificity, and ultrastructural localization of HMB-45 antigen in pigmented ocular tumors

PURPOSE

To evaluate the expression of the monoclonal HMB-45 antibody in melanocytic and nonmelanocytic ocular tumors and seek "activated" cellular subpopulations in an attempt to distinguish between benign and malignant melanocytes, to compare HMB-45 and S100 activity, and to determine the specificity of this tumor marker for melanocytic ocular lesions.

METHODS

Immunohistologic investigations were performed with paraffin-embedded tissue of 10 acquired conjunctival melanoses, 19 conjunctival nevi, 34 conjunctival melanomas, 69 uveal melanomas, 20 basal cell carcinomas of the lid, 20 cystic dermoids, 15 hemangiomas of the lid, 20 conjunctival papillomas, 20 squamous cell carcinomas, 20 pterygia, 11 sebaceous gland carcinomas, 10 retinoblastomas, and 5 choroidal metastatic carcinomas. The avidin-biotin peroxidase technique and monoclonal HMB-45 antibody were used. The distribution of S100 protein was studied in the melanocytic tumors for comparison. To localize the HMB-45 antigen, lowicryl-embedded tissue of uveal melanomas was investigated immunoelectron microscopically.

RESULTS

More than 95% of the conjunctival and choroidal melanomas expressed the HMB-45 antigen, while S100 was found in all melanomas of the conjunctiva and in 91% of the uveal melanomas. In benign melanocytic lesions of the conjunctiva (nevi and melanocytes), especially the intraepithelial and junctional components stained with HMB-45, and at the site of tumor invasion, infiltrating cells showed increased HMB-45 reactivity. On the whole, HMB-45 antigen was less evenly distributed in the melanocytic tumors investigated than S100 antigen. All nonmelanocytic ocular tumors revealed no HMB-45 expression. Retinal pigment epithelium and tumor-free choroid were negative for HMB-45. The HMB-45 antigen was immunoelectron microscopically found in melanosomes at stages II and III.

CONCLUSION

HMB-45 immunohistology helps in distinguishing melanocytic from nonmelanocytic ocular tumors and often clarifies the front of tumor invasion. The stronger HMB-45 reactivity probably reflects melanocytic activation, but a sharp line between benign and malignant melanocytes cannot be drawn.

Ultrasound biomicroscopy of anterior segment tumors

BACKGROUND

Ultrasound biomicroscopy is a new method of imaging the anterior segment of the eye at microscopic resolution using high frequency ultrasound.

METHODS

A prospective study was performed to evaluate the use of ultrasound biomicroscopy in imaging anterior segment tumors. Forty-five patients underwent clinical examination followed by slit-lamp photography, anterior segment B-scan ultrasonography, and ultrasound biomicroscopy according to an established protocol.

RESULTS

All lesions were clearly imaged by ultrasound biomicroscopy, while only 17 were detectable by conventional B-scan ultrasound. Ultrasound biomicroscopy allowed precise measurement and visualization of subsurface features in small tumors. Differentiation between solid and cystic lesions was easily achieved. The margins of ciliary body tumors could be more accurately defined. Histopathologic correlation was possible in four cases managed surgically. Ultrasound biomicroscopy images compared favorably with low-power microscopy. No complications were encountered.

CONCLUSION

Ultrasound biomicroscopy proved a valuable new noninvasive technique in the evaluation of anterior segment tumors.

Spindleform scleropathy: collagen changes of the sclera. A pathologic report

To our knowledge, this is the first pathologic report of interscleral collagen bundle changes occurring as well-defined spindleform lesions randomly interspersed within the sclera. The lesions were observed in an otherwise healthy 75-year-old man whose eye was enucleated because of a uveal malignant melanoma. There are few reports in the literature of focal scleral changes of a predominantly acid mucopolysaccharide nature. The entity we observed in this case differs from these reports by its spindleform appearance, random distribution (not overlying the melanoma) and predominantly vicinal glycol nature. Histopathologic, histochemical, and ultrastructural studies revealed that the lesions were not the result of mucoid degeneration of the scleral collagen and not an abnormal collagen structure.

Orbital squamous cell carcinoma after retinal detachment surgery

We report on a 76-year-old patient with a squamous cell carcinoma of the left orbit. The tumour had no connection with the conjunctiva but was located at the site of an encircling band which had been inserted 13 years before. A major part of the tumour presented as a well circumscribed solid mass within the extraocular tissues next to the inferior equator, but the exenteration specimen also showed tumour extension within the adjacent choroid. Histological examination showed a well differentiated keratinising squamous cell carcinoma with numerous mitotic figures and many epithelial pearls. A thorough examination in search of a primary carcinoma of the lacrimal gland or the sinus, with invasion into the orbit, or an epithelial neoplasm elsewhere suggestive of metastatic disease into the choroid did not reveal any specific pathological findings. Thus the most probable origin of the tumour seems to be epithelium which had been misplaced during retinal detachment surgery and had subsequently undergone malignant transformation.

[Histological classification of uveal melanoma]

Cytological classification of choroidal malignant melanomas recommended by WHO and based on the Callender classification (spindle A and B, mixed and epithelioid) is presented. Prognosis according to the histological types is discussed.

Nucleolar organiser regions in iris melanocytic tumours: an accurate predictor?

A silver staining technique which demonstrates the nucleolar organiser region (NOR) was used in paraffin sections of iris naevi and melanomas. The technique shows argyrophilic NOR associated proteins (AgNORs) which are seen in nuclei as black dots. In nine iris naevi the AgNOR count ranged from 1.54 to 3.82 (mean 2.73), in 21 melanomas from 1.89 to 8.31 (mean 4.67). Mean AgNOR counts greater than four dots per nucleus were only seen in malignant lesions, thereby differentiating between benign and malignant tumours, whenever high AgNOR counts were found. We subsequently examined three tumours in the intermediate group of aggressive naevi, Jakobiec group 6: there were counts averaging 4.08 but with a wide standard deviation of counts indicating that the behaviour of this group of aggressive tumours is likely to depend on the percentage of cells bearing the higher numbers of NORs, which may represent mitotic potential or increased metabolic rate.

Congenital hypertrophy of the retinal pigment epithelium. Electron microscopic and morphometric observations

Congenital hypertrophy of the retinal pigment epithelium (CHRPE) is a well-circumscribed, flat, pigmented fundus lesion that is stable and generally nonprogressive. Light and electron microscopy and morphometric analysis was used to study a lesion with the clinical characteristics of CHRPE found in an eye enucleated for a posterior segment malignant melanoma. These studies showed that the lesion was composed of tall, maximally pigmented RPE cells that had a density 1.7 times greater than the density of the adjacent normal peripheral RPE. These observations suggested that cellular hyperplasia and hypertrophy may contribute to CHRPE. Ultraviolet fluorescence microscopy showed no autofluorescent granules of lipofuscin in the CHRPE, suggesting that the lesion's constituent cells lack the capacity to phagocytose and digest photoreceptor outer segments. Photoreceptor degeneration in the overlying retina consequent to this functional defect could be responsible for the localized visual field defects that typically occur in patients with CHRPE.

Differences in nuclear pore density among human choroidal melanoma cell types

Two cases of mixed cell type choroidal melanoma were examined by means of conventional and freeze-fracture electron microscopy. Data on average nuclear pore density were readily collected from freeze-fracture replicas of spindle A, spindle B, and epithelioid cells. Highly significant (p less than 0.001) differences in pore densities were found among the three cell types. Pore density was lowest in spindle A cells, intermediate in spindle B cells, and highest in epithelioid cells. The possible relationship between nuclear pore density and nucleolar activity as well as the potential usefulness of this new finding as a prognostic indicator in cases of choroidal melanoma are discussed.

Bilateral choroidal neonatal neuroblastoma

We treated a bilateral, well-differentiated neuroblastoma of the choroid in a patient who had congenital abdominal neuroblastoma. Although orbital metastasis of neuroblastoma is common, intraocular metastasis is not. In our patient, there was no amplification of the N-myc oncogene in the tumor of either eye. This is consistent with early-stage primary neuroblastoma. Histologically, the tumors were identical in each eye and well differentiated with Homer Wright rosettes; most neuroblastoma metastases have few rosettes and are composed of more undifferentiated, anaplastic cells. We believe that our patient had bilateral primary tumors and not metastatic tumors.

Massive fibrosis of extraocular muscles related to intraocular tumor

A resin histological and ultrastructural study of 9 fibrotic extraocular muscles from 2 patients who underwent enucleation because of advanced intraocular malignant melanoma is reported. Total fibrosis of the extraocular muscles was evident in one case and extensive fibrosis in the other case. The patients did not suffer from congenital fibrosis syndrome. Ultrastructurally, the muscle tissue was replaced by collagen fibrils showing great variability of caliber.

Diffuse iris nevus in oculodermal melanocytosis: a light and electron microscopic study

We studied by light and electron microscopy the diffuse iris nevus of an eye in a 16-year-old patient with oculodermal melanocytosis and choroidal malignant melanoma. The nevus cells in the anterior border layer of the iris appeared to be poorly differentiated, showing moderate infolding of the nuclear membrane with heterochromatin clumping, watery cytoplasm, abundant mitochondria, fine filaments, rough endoplasmic reticulum, and numerous pinocytotic vesicles. Small scattered immature melanosomes and occasional giant melanosomes were observed in these cells. Deep in the iris stroma, however, nevus cells were found singly or in small groups, and were associated with an increasing number of melanized melanosomes and cytoplasmic filaments and reduced numbers of other cytoplasmic organelles, such as mitochondria and free ribosomes. Differentiation of the iris nevus cells appeared to progress from the anterior border layer toward the iris stroma. This observation suggests that intrastromal nevi may be more benign than nevi with surface plaque. The ultrastructural characteristics of the diffuse nevi of oculodermal melanocytosis were compared with those of other iris nevi.

Effect of dicarboxylic acids (C6 and C9) on human choroidal melanoma in cell culture

In cell culture, azelaic acid (C9) has been shown to have an antiproliferative and cytotoxic effect on human and murine malignant cutaneous melanocytes. Normal melanocytes are unaffected, as are normal choroidal melanocytes. Here, effects on cell kinetics and ultrastructure of cells of a human choroidal melanoma line have been studied. Cells were exposed to single doses of disodium salts of azelaic (C(9)2Na) and adipic (C(6)2Na) acids at concentrations of 10(-2) M and 5 X 10(-2) M for 48 hr. C(9)2Na at 5 X 10(-2) M had a significant effect on proliferation at 24 and 48 hr and this was not reversible on removal of diacid. At 5 X 10(-2) M for 24 hr, C(6)2Na had no effect and at 5 X 10(-2) M for 48 hr had an effect which was marginally significant, but reversible. Swelling and disruption of mitochondria was seen in cells exposed to C(9)2Na at 5 X 10(-2) M for 1 hr and longer, but even at 10(-1) M, cells exposed to C(6)2Na were minimally affected. The results could encourage further investigations of the feasibility of azelaic acid therapy for uveal and ocular adnexal melanoma.

Retinal ultrastructural findings in cone degeneration

We studied an eye from a 73-year-old man with a sporadic type of retinal cone degeneration and choroidal melanoma. Histologic and ultrastructural studies of the nasal retina unaffected by the choroidal melanoma showed alterations at the outer retina predominantly involving the photoreceptors and retinal pigment epithelium. A wide spectrum of pathologic changes were observed, ranging from near normal retina showing only photoreceptor outer segment disease (distortion and kinking) to grossly pathologic regions where photoreceptor cell bodies were sparse and their outer segments absent. The retinal pigment epithelium in minimally affected regions of the retina showed an increased proportion of the melanin complement of the cell within complex granules. In severe disease, many cells showed only giant complex granules with no free melanin. Retinal pigment epithelial cell migration and relocation around blood vessels was also noted in severe disease.

Diffuse malignant change in a ciliochoroidal melanocytoma in a patient of mixed racial background

A 69-year-old man of mixed racial background was discovered to have a large, deeply pigmented mass in his left eye with a history of rapid growth during the previous 6 months. The eye was enucleated, and histopathological examination revealed an epithelioid malignant melanoma arising from a melanocytoma.

Electron microscopy of three cases of choroid malignant melanomas

Ultrastructural study, by Scanning and Transmission Electron Microscopy, of three choroidal melanomas allows us to depict main features and cellular types of melanomas and to discuss our results with precedent studies. One case of balloon-cell tumor shows an unusual (from unknown genesis) substance, intra- or extracellularly located, but always near pigment cells expansions.

Olfactory neuroblastoma metastatic to the eye

A case of olfactory neuroblastoma metastatic to the choroid is reported and described. Histologically, the tumor consisted of islands of small round cells, many of them surrounding blood vessels in a 'pseudorosette' pattern. Numerous mitotic figures were present. Transmission electron microscopy reveals neuritic processes containing neurosecretory granules and microtubules, features characteristic of olfactory neuroblastoma. This is the first published case of an olfactory neuroblastoma demonstrating intraocular metastasis.

The effect of rapid freezing on uveal melanomas

We studied the immediate effects of rapid freezing on 19 variously sized uveal melanomas that were subjected to cryoenucleation using liquid nitrogen and a cryoring by light and electron microscopy and tissue culture. The freezing time and the temperature of 11 lesions were recorded. The light microscopic finding of an intranuclear clear center with peripheral displacement of clumped chromatin against the nuclear membrane was suggestive of intranuclear ice crystal formation but did not indicate cellular death of the tumors. The major ultrastructural changes, including plasmalemmal breaks, dissolution of cytoplasmic matrix, and damage to various organelles, however, suggested acute necrosis in tumors not exceeding 7 mm in elevation. Failure of the melanoma cells to grow in tissue culture and positive staining with trypan blue support the contention of tumor death. The late effects of rapid freezing were also evaluated in another case of uveal melanoma. The eye was enucleated six months after cryopexy. Histopathologic findings showed that the tumor was necrotic. Failure of the neoplasm to regress (noted clinically) was related to edema and inflammatory infiltrates.

Heterotopic smooth muscle in the choroid of two patients with cryptophthalmos

The mode of inheritance in the complete cryptophthalmic syndrome is not clear in all cases. In two of our patients with complete cryptophthalmos, one showed a probable autosomal-recessive inheritance, while in the other patient, the mode of transmission could not be determined. Light and electron microscopic studies of the globes demonstrated heterotopic smooth-muscle tissue in the anterior part of the choroid in these two patients. Although these findings might be explained on the basis of a lack of directional growth of the embryonic ciliary muscle cells during the early embryonic period, we favor a simple anatomical explanation based on differentiation arrest of the anterior segment. During the fourth month of gestation, the growing optic cup presumably fails to advance forward normally and to differentiate. The relatively normally developing posterior segment extends posteriorly. The "stretching" backward of the ora serrata during the seventh month of gestation "drags" with it the ciliary smooth muscle that did not advance forward due to the earlier arrest. Thus, in the definite cryptophthalmic eye, the smooth-muscle tissue is localized within the anterior choroid.

Tissue culture of human choroidal melanoma cells obtained by fine-needle aspiration biopsy

The optimal treatment of choroidal melanoma is controversial. Many patients are now being treated with nonenucleation therapies. Fine-needle aspiration biopsy of intraocular tumors may well prove to be safe; we used a needle biopsy technique on three freshly enucleated globes and established choroidal melanoma cell lines in culture from these specimens. This report describes our needle biopsy and tissue culture techniques.

Benign melanoma of the choroid in a beagle: ophthalmological, light and electron microscopical investigations

A pigmented choroidal tumor was diagnosed in a 13-month-old male beagle. The tumor was observed ophthalmoscopically over a period of seven years. Light and electron microscopical features are those of a benign melanocytic tumor with marked histological similarities to uveal nevus in man.

Intraocular hemangiopericytoma

A 40-year-old woman had an intraocular lesion consistent with a choroidal hemangioma. Xenon arc photocoagulation was applied to reduce subretinal fluid, and the lesion remained stationary until the patient's death eight years later. The lesion was composed of spindle-shaped and ovoid cells with numerous inconspicuous capillaries. The tumor cells were surrounded by reticulin-positive fibers. The diagnosis of hemangiopericytoma was confirmed by electron microscopy, which demonstrated proliferating pericytes associated with basal lamina. Although hemangiopericytomas are occasionally found in the orbit, to our knowledge this report is the first of an intraocular hemangiopericytoma. Because the pericyte is an integral component of the choroidal vasculature, the origin of this tumor in the choroid is not unexpected. The diagnosis of hemangiopericytoma should be considered when evaluating vascular choroidal lesions.

Balloon cell malignant melanoma of the choroid: ultrastructural studies

I reported the clinical, pathological, and ultrastructural findings in 2 cases of balloon cell malignant melanoma of the choroid. Degradation of the melanosomes of the tumour cells appeared to be the primary biological disturbance in the cell organelles, followed by secondary increase in intracellular lipid secretion and accumulation, leading ultimately to the formation of the balloon cells. Despite the fact that balloon cells are indicative of degeneracy and impending necrosis of the tumour cells, metastases were present in both cases. One of the conclusions this article provides is that the presence of balloon cells does not alter the prognosis of malignant melanomas of the choroid.

[Heterotopic smooth muscle in the choroid]

A histological and ultrastructural description of a case with an area of smooth muscle in the choroid of both eyes in presented. This was a chance finding in the globes of a deceased female patient whose lids (OU) as well as the conjunctiva and sclera of one side were affected by mycosis fungoides. The heterotopic smooth muscle in the choroid is interpreted as being an isolated malformation in otherwise nondysplastic eyes. It is possible that the rare leiomyomas of the choroid occur in such heterotopias, which have not been observed before.

Metastatic carcinoma masquerading as scleritis

A 36-year-old white man abruptly developed painless visual loss in his left eye. Fundoscopic evaluation revealed a shallow left superotemporal retinal detachment with an underlying yellowish choroidal infiltrate. Fluorescein angiography disclosed indistinct choroidal leakage, and both B-scan ultrasonography and computed tomography demonstrated superotemporal thickening of the choroid and the sclera. The patient was diagnosed clinically as having a scleritis and an associated exudative retinal detachment. He was placed on a several months' course of systemic prednisone, and despite this regimen, his condition worsened with the appearance of severe pain, proptosis and displacement of the eye, glaucoma, and intense episcleral and scleral injection. The eye was enucleated and displayed externally a massively thickened sclera superotemporally. Light microscopic evaluation of the enucleated globe revealed an extensively necrotic tumor growing diffusely within the choroid; infiltrating viable tumor cells were discovered within the sclera and episclera. The tumor cells had the characteristics of a well-differentiated, mucin-producing adenocarcinoma. Electron microscopic studies demonstrated lumen-forming tumor cells with apical villi, cytoplasmic pseudolumens, pools of cytoplasmic glycogen, and multiple types of inclusions, including mucin, lipid, and electron-dense secretory granules similar to those in pulmonary Clara cells. These findings were consistent with a bronchiolo-alveolar carcinoma. The patient subsequently developed bilateral reticulo-nodular pulmonary infiltrates, also typical of this tumor. The unusual clinical features of this case of "malignant scleritis" are discussed in light of the final diagnosis.

Choroidal ganglioneuroma in neurofibromatosis

A twenty-one year old female with previously unsuspected neurofibromatosis presented for evaluation of a blind painful eye. Histopathologic examination of the enucleated specimen revealed choroidal thickening with ovoid bodies and proliferation of connective tissue with pigment-containing cells and ganglion-like cells. Electron microscopic study of the latter cell population revealed typical morphologic features of ganglion cells, including numerous electron-dense intracellular granules and an abundance of mitochondria and rough endoplasmic reticulum. These pathologic findings were interpreted as consistent with the diagnosis of choroidal ganglioneuroma occurring in the context of ocular neurofibromatosis. The literature concerning this unusual tumor is reviewed and the possible relationship of this lesion to neurofibromatosis and other disorders of neural cresent proliferation are briefly discussed.

Surface morphology of explants from the human retinal pigment epithelium in culture. A scanning electron microscopic study

The alterations in surface morphology in human retinal pigment epithelium in explant culture was studied by scanning electron microscopy. After 14 days in culture, large areas of the epithelium showed well preserved surface villi. In some zones, however, the density of the finger-like villi were reduced and the shorter villi became more visible. The short villi are lamellar in structure and constitute systems of communicating membranous folds and not isolated structures as previously believed. Most of the tall finger-like villi were found to have their bases on the top of these folds. Dead cells followed 2 different pathways of degeneration. Some showed large ruptures in the membrane, followed by expulsion of organelles and finally detachment of the cell from Bruch's membrane. With other cells, a progressive disintegration of the cell membrane was observed. The first type of degeneration occurred most frequently in dilated, single cells, whereas the latter type was found in larger areas of necrosis.

Ovoid bodies in choroidal neurofibromatosis

We studied the ultrastructure of the ovoid bodies in choroidal neurofibromatosis. Ovoid bodies consisted of groups of the same kind of elongated cells arranged in lamellar patterns. The elongated cell was characterized by a fragmented circumferential basal lamina, groups of pinocytotic vesicles, a desmosomelike intercellular contact, and intimate contact with axons. These findings suggest that elongated cells are proliferated Schwann's cells and ovoid bodies do not correspond with real sensory nerve end organs; rather, they are enlarged peripheral nerves due to neoplastic hyperplasia of Schwann's cells around axons.

Three basic types of foveal involvement in choroidal melanomas

Three cases are used to demonstrate the main types of cystoid macular edema, which have been seen to occur in association with choroidal melanomas: 1) direct involvement in cases, where the neoplasm is located under the foveal retina, 2) indirect involvement due to a subfoveal exudate in choroidal melanomas distant to the fovea and 3) indirect foveolar involvement without associated subfoveal tumor or exudate. A recording of the pathology of these three basic reaction patterns of the central retina in choroidal melanomas is considered important. It is emphasized, that combinations of the reactions are common and may result in more complex situations.

The fenestrations of the choriocapillaris in the presence of choroidal melanoma

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Macular edema and cystoid macular edema

We examined the foveomacular regions from three eyes in which fluorescein angiography had demonstrated the characteristic appearance of cystoid macular edema by light and electron microscopy. Cystoid macular edema was present in two eyes (one of which was from a 63-year-old diabetic man) that contained peripheral choroidal melanomas, and in a third eye from a patient with diabetes only. By light microscopy, cystoid macular degeneration was obvious only in the third eye. The electron microscopic findings common to all three eyes were widespread swelling and necrosis of Müller cell cytoplasm. There was no enlargement of intercellular spaces. There was secondary neuronal degeneration. Retinal vascular changes, consisting mainly of endothelial cell abnormalities, were found in all cases but were far more common in the two eyes from diabetic patients. The retinal vascular changes were probably the cause of the cystoid macular edema.

Multifocal choroidal melanoma in ocular melanocytosis

A 29-year-old white women had ocular melanocytosis with scleral pigmentation and a diffuse choroidal nevus. The eye was enucleated because of two choroidal tumors. Light and electron microscopy showed two separate choroidal melanomas with differential cytologic characteristics. The extreme rarity of multicentric choroidal melanomas support the belief that ocular melanocytosis predisposes to malignancy.

An ultrastructural study of melanocytomas (magnocellular nevi) of the optic disk and uvea

We examined by light and electron microscopy five melanocytomas from four patients. Two types of cells were observed in each tumor. The predominant cell type in most of the tumors studied consisted of plump polyhedral nevus cells that contained numerous giant melanosomes. These cells showed advanced differentiation. They appeared to be metabolically inactive and to have been the cause of the heavy pigmentation and benign nature of these tumors. The second variant of melanocytoma cells were smaller spindle-shaped cells that were lightly pigmented. Other morphologic features of these cells such as high nucleus-cytoplasm ratio, prominent nucleolus, nuclear membrane infolding, numerous mitochondria, prominent rough endoplasmic reticulum, and free ribosomes, indicated a metabolically active cell, which may explain the infiltrating behavior of these tumors.

Heterotransplantation of human choroidal melanoma into the athymic "nude" mouse

The investigation of the structure and behavior of malignant melanoma of the uveal tract in man has been limited by the lack of a ready source of human tumor and an animal model in which the tumor resembles that in the human choroid. We now report the observation that fresh surgical specimens of human choroidal melanoma can be successfully transplanted into the posterior segment of the "nude" mouse (a homozygous mutant, nu/nu, with a defect in cellular immunity) and can be serially transplanted. This model utilizing human melanoma should be useful for the study of the natural history of this disease, as well as the response to various chemotherapeutic agents.

Scanning electron microscopy of frozen-cracked, dry-cracked and enzyme-digested tissue of human malignant choroidal melanomas

By applying cracking and enzyme-digestion methods to tissue of human malignant choroidal melanomas, SEM was used to visualize the interior of the cells, their membranes, nuclei and organelles. Single cells were depicted to their full extent. Apart from a three-dimensional impression of the structures and their surfaces, the methods also made it much easier to measure cells and cell components than by conventional methods.

Vascular basophilia in ocular and orbital tumors

The occurrence of vascular basophilia in ocular tumors has been a selective histologic feature of retinoblastomas. We recently observed a metastatic oat-cell carcinoma to the choroid which also demonstrated such a vascular hematoxyphilia. Histologic review of a variety of ocular and orbital metastatic carcinomas failed to yield a similar basophilic pattern. Examination of 100 consecutive retinoblastomas for vascular basophilia revealed an incidence of 6.0%. Similar material was not seen in any of 125 melanomas, including 10 with areas of necrosis. Histochemical studies showed the basophilic material to be DNA, and electron microscopy revealed the nuclear debris of pyknotic tumor cells to be continuous with identical material surrounding the adjacent blood vessels. The pathogenesis of vascular deposition of DNA in these two ocular tumors remains unclear. This finding most likely represents a form of tumor activity requiring comparatively healthy blood vessels to adequately precipitate liberated nucleic acids being filtered from the necrotic and degenerating tumor tissue.

[Study of uveal malignant melanoma with the electron microscope (author's transl)]

Twelve cases of uveal malignant melanoma, including the principal histologic types of this neoplasm according to Callender, were studied with the electron microscope. Nuclear inclusions were observed in each case, more frequently in epithelioid cells: they were probably correlated with nuclear hyperactivity. Melanogenesis in neoplastic cells was sometimes abnormal because of the granular structure of the premelanosomes, of the difference in size and in shape melanosomes, of the difference in size and in shape of the pigment granules and of the different stage of evolution of the premelanosomes in the cell. The size and the degree of reticulation of nucleoli and the number of free ribosomes and mitochondria increased from spindle A, to spindle B and epithelioid cells. This behaviour probably depends on an increasing metabolic activity which is related to the increasing degree of malignancy.