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Biomedical subjects

C L Shields

Publications and source records attributed to C L Shields.

At least 235 records · Page 13Linked to original sources
PubMed1994

Primitive neuroectodermal tumor of the orbit.

A 10-year-old girl developed a lump in the lateral aspect of the right eyebrow over a 3-week period. Computed tomography and magnetic resonance imaging revealed a soft-tissue mass in the superolateral aspect of the right orbit associated with zygo-maticofrontal bone erosion and hyperostosis. An incisional biopsy specimen was studied using light microscopy, immunohistochemical staining, and electron microscopy, resulting in a diagnosis of peripheral primitive neuroectodermal tumor. The results of an extensive evaluation for systemic involvement were negative. The patient was subsequently treated with chemotherapy and radiation therapy. Primary primitive neuroectodermal tumor of the orbit is rare. The differential diagnosis and the diagnostic features of this entity are discussed herein.

Child↗
PubMed1994

The role of fat-suppression technique and gadopentetate dimeglumine in magnetic resonance imaging evaluation of intraocular tumors and simulating lesions.

OBJECTIVE: Recent studies have shown that contrast (gadopentetate dimeglumine)-enhanced magnetic resonance imaging is useful in evaluating intraocular tumors and differentiating uveal melanoma from other simulating lesions. The purpose of this study was to study prospectively the role of fat-suppression technique and gadopentetate dimeglumine-enhanced magnetic resonance imaging in the evaluation of intraocular neoplasia. PATIENTS: Forty-three uveal melanomas and 20 other simulating intraocular lesions from 63 patients were prospectively evaluated on non-contrast-enhanced and post-contrast-enhanced T1-weighted images with and without fat-suppression technique and on T2-weighted images. RESULTS: Forty-one uveal melanomas (95%) were detected with standard pulse sequences and showed the characteristic hyperintense signal on non-contrast-enhanced T1-weighted images and hypointense signal with respect to the vitreous on T2-weighted images. All 33 uveal melanomas evaluated on non-contrast-enhanced T1-weighted images with fat-suppression technique were detected on non-contrast-enhanced images with fat-suppression technique. The intensity of the signal was statistically associated with the degree of pigmentation of the tumor on T1-weighted images with fat-suppression technique (P = .03). On post-contrast-enhanced T1-weighted images with or without fat-suppression technique, the 43 uveal melanomas showed enhancement. The degree of tumor enhancement was not statistically related to the degree of tumor pigmentation or the location of the tumor. Among the other simulating intraocular lesions, choroidal metastasis, retinoblastoma, choroidal leiomyoma, and medulloepithelioma demonstrated the same features on magnetic resonance imaging studies as uveal melanoma demonstrated on non-contrast-enhanced and post-contrast-enhanced T1-weighted images with or without fat-suppression technique. In our series, choroidal hemangioma, choroidal osteoma, posterior scleritis, retinal hemangioma, and Coats' disease can be differentiated from other amelanotic intraocular tumors by their characteristics on magnetic resonance imaging studies. CONCLUSIONS: We concluded that pre-and post-contrast-enhanced T1-weighted images with fat-suppression technique are most helpful in detecting small intraocular tumors with a thickness of more than 1.8 mm and in evaluating intraocular neoplasms and simulating lesions, particularly when T2-weighted images are not available. Moreover, in juxtapapillary choroidal or retinal tumor, fat-suppression technique may help in the detection of possible optic nerve or orbital extension by improving the conspicuousness of the tumor.

Adipose Tissue↗
PubMed1994

Observations on seven cases of intraocular leiomyoma. The 1993 Byron Demorest Lecture.

A review of seven cases of intraocular leiomyoma personally managed by the authors disclosed clinical and histopathologic characteristics that serve to differentiate this uncommon tumor from uveal melanoma. Leiomyoma generally occurs in younger patients and has a definite predilection for females. It tends to affect the ciliary body and peripheral choroid rather than the posterior choroid. In contrast to melanoma, which is located in the uveal stroma, leiomyoma usually is located in the supraciliary or suprachoroidal space. During transillumination, leiomyoma usually transmits light readily, whereas most melanomas cast a shadow. If intraocular leiomyoma is suspected clinically, the best management seems to be removal by a modified lamellar sclerouvectomy. In contrast to melanoma, leiomyoma shows positive immunoreactivity for muscle markers and negative immunoreactivity for melanoma-specific antigen and neural markers.

Adult↗
PubMed1994

Adenocarcinoma of retinal pigment epithelium arising from a juxtapapillary histoplasmosis scar.

A 66-year-old woman underwent a transocular fine-needle aspiration biopsy for an enlarging mass arising from a juxtapapillary histoplasmosis scar in the left eye. The cytologic study revealed pigmented malignant cells, suggesting that the lesion was either a malignant choroidal melanoma or an adenocarcinoma of the retinal pigment epithelium. The eye was enucleated and histopathologic studies revealed findings suggestive of an adenocarcinoma of the retinal pigment epithelium. Immunohistochemical stains were positive for cytokeratin and were negative for melanoma-specific antigen, supporting an epithelial origin of the neoplasm. It is possible that the tumor developed as a neoplastic transformation of a reactive proliferation of the retinal pigment epithelium in a histoplasmosis scar. The possible association between a chorioretinal scar and the development of a tumor of the pigment epithelium is discussed herein.

Adenocarcinoma↗
PubMed1994

Cytogenetic findings in primary uveal melanoma.

We analyzed cytogenetic abnormalities in 10 cases of primary uveal melanoma. Clonal chromosomal abnormalities were present in nine cases. Chromosome 6 was most commonly affected (seven cases) and included gain of material from 6 and/or loss of material from 6q. Trisomy of chromosome 8 or gain in material from 8q, mostly in the form of an i(8q) resulting in three to five copies of the 8q segment was seen in six cases. Monosomy of chromosome 3 and rearrangements of chromosome 9 were less frequent and were altered in three cases each. Clinical, histopathologic, and cytogenetic abnormalities are correlated.

Adult↗
PubMed1994

Current management of retinoblastoma.

OBJECTIVE: The recommended management of retinoblastoma based on personal experience with the assessment and treatment of more than 450 children with this intraocular malignant lesion is presented. RECOMMENDATIONS: Although retinoblastoma is usually managed by enucleation, the treatment of each case must be individualized; in an increasing number of children, the techniques of irradiation, photocoagulation, or cryotherapy are being used. In some patients, a combination of these techniques is necessary. Chemotherapy is often used to prevent distant metastatic involvement, although its effectiveness as a prophylactic treatment has not been clearly established. Because metastatic retinoblastoma is often fatal, intense chemotherapy is recommended in this setting. CONCLUSION: The prognosis for vision and life in patients with retinoblastoma has improved considerably during the past century, primarily because of earlier recognition of the tumor and use of modern therapeutic methods. All children of parents with a family history of retinoblastoma should be examined by a qualified ophthalmologist immediately after birth in order to detect and treat this condition as early as possible.

Child↗
PubMed1994

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.

Adult↗
PubMed1994

Uveal metastasis from carcinoid tumor. Clinical observations in nine cases.

BACKGROUND: Carcinoid tumor is a low-grade malignancy that usually arises in the gastrointestinal tract or bronchus and rarely metastasizes to the eye. Metastasis of carcinoid tumor to the uvea can be confused clinically with other primary and metastatic uveal tumors. METHODS: The authors reviewed the records of 410 consecutive patients with uveal metastases referred to the Ocular Oncology Service at Wills Eye Hospital to identify those in whom carcinoid tumor was the primary neoplasm. The authors evaluated the clinical features of these metastases. RESULTS: Of 410 consecutive patients with uveal metastases, the primary neoplasm was a carcinoid tumor in 9 (2.2%). There were four men and five women. The mean age at ocular diagnosis was 50 years. In five patients (56%), the primary tumor was undiagnosed at ocular presentation. In the other four patients, the mean time interval from diagnosis of the primary carcinoid tumor to uveal metastasis was 89 months (range, 55-180 months). The site of the primary carcinoid tumor was the bronchus in seven patients, the esophagus in one, and the thymus in one. The site of intraocular metastasis was the choroid in six patients, the ciliary body in two, and the iris in one. All choroidal tumors had a characteristic orange color. Initial ocular treatment included external beam radiotherapy in five patients, plaque radiotherapy in two, argon laser photocoagulation in one, and local resection in one. Ocular tumor control was achieved in each patient. After a mean follow-up of 34 months, four patients (44%) are still alive. Five patients have died, with a mean survival of 34 months (range, 2-104 months) after the diagnosis of uveal metastasis. CONCLUSIONS: Uveal metastasis from carcinoid tumor is rare and tends to arise from the bronchus. Clinically, it has a distinctive orange color and may be associated with a longer systemic survival, compared with uveal metastasis from other primary sites.

Adult↗
PubMed1994

Clinical management of retinoblastoma.

There have been many recent advances in the diagnosis and management of children with retinoblastoma. Regarding diagnosis, the judicial use of ancillary studies, particularly B-scan ultrasonography, has been instrumental in supplementing the diagnosis when opaque media preclude a clear view of the underlying neoplasm. Computed tomography and magnetic resonance imaging are important in the early detection of associated pinealoblastoma, which occurs as part of the recently described syndrome of "trilateral retinoblastoma." With regard to management, the technique of enucleation continues to improve and the scleralized hydroxyapatite implant is now available to provide a better cosmetic appearance and better motility of the artificial eye. Methods have been described for harvesting fresh tumor tissue immediately after enucleation for special DNA studies. Recent reports have documented a decreasing frequency of enucleation and an increasing tendency to use eye-preserving methods of management. Plaque radiotherapy, which provides more localized irradiation to the specific tumor, is gradually supplanting external beam irradiation for localized retinoblastoma that does not exhibit extensive vitreous seeding. The indications and contraindications for cryotherapy and photocoagulation have been more clearly delineated. The role of chemotherapy is being evaluated in the treatment of primary retinoblastoma and for metastatic disease. New breakthroughs in genetic research are being applied to clinical genetic counseling. The prognosis for life and for preservation of vision has improved greatly in recent years.

Combined Modality Therapy↗
PubMed1994

Impact of enucleation versus plaque radiotherapy in the management of juxtapapillary choroidal melanoma on patient survival.

The records of 265 consecutive patients with juxtapapillary choroidal melanoma were reviewed and a statistical non-randomised retrospective study was performed to evaluate the risk for metastasis and compare the survival rate of patients treated with plaque radiotherapy or enucleation. To obtain sufficient overlap between the enucleation and plaque radiotherapy, the statistical analysis was limited to an adjusted subgroup of 127 patients who met eligibility criteria for plaque radiotherapy and who had a minimum of 3 years of follow up after treatment. In the adjusted subgroup of 127 patients, 92 patients (72%) were initially treated with enucleation and 35 (28%) with plaque radiotherapy. In both univariate and multivariate logistic analysis models, the age of the patient (> 50 years), tumour thickness (> 3 mm), and treatment by age interaction were found to be significant factors for development of distant metastasis. In patients younger than 50 years, the method of treatment (enucleation versus plaque radiotherapy) did not significantly affect the risk of metastasis. For those older than 50 years, there was a non-significant trend for patients in the enucleation group to be at a higher risk for metastasis than those in the plaque group. In the enucleation group, patients older than 50 years had a significantly higher incidence of distant metastasis than those younger than 50 years. In the plaque radiotherapy group, there was no significant higher incidence of metastasis in patients younger than 50 years than in those older than 50 years. When a Cox proportional hazards model was used to evaluate the survival rate, there was the same statistically significant effect of treatment by age interaction as was found in the multivariate logistic model on survival time. Moreover, there was a significant effect of treatment by tumour thickness interaction on survival time. Patients in the enucleation group had a better survival rate when the thickness of the tumour was less than 3 mm compared with a tumour of more than 3 mm. There were no apparent effects of tumour thickness on survival for patients treated with plaque radiotherapy. From these results, the authors currently recommend plaque radiotherapy as a viable option to enucleation in patients with juxtapapillary choroidal melanoma.

Adolescent↗
PubMed1994

Problems with the hydroxyapatite orbital implant: experience with 250 consecutive cases.

The coral derived hydroxyapatite sphere is a popular, integrated orbital implant designed to provide improved motility of the ocular prosthesis following enucleation. Although the implant has rapidly become widely used by ophthalmologists, little information is available regarding the problems of this technique in a large series of cases. Experience with 250 consecutive cases of hydroxyapatite orbital implant use was reviewed and the problems of the implants and their management investigated specifically. The reasons for enucleation included uveal melanoma (157 cases), retinoblastoma (70 cases), blind painful eye (22 cases), and intraocular medulloepithelioma (one case). Earlier treatment to the eye was performed before enucleation in 47 cases and included repair of ruptured globe (17 cases), plaque radiotherapy (18 cases), external beam radiotherapy (six cases), and others (six cases). During a mean of 23 months' follow up (range 6-40 months), there have been no recognisable cases of orbital haemorrhage related to the implant, and no cases of implant extrusion or implant migration. There was one case of presumed orbital infection (culture negative) that resolved with intravenous antibiotics and the implant was retained within the orbit. Other problems included conjunctival thinning in eight cases managed by observation and prosthesis adjustment, and conjunctival erosion in four cases managed by combinations of scleral patch graft, conjunctival flap, and prosthesis adjustment. The conjunctival erosion was caused by a poorly fitting prosthesis in three cases and wound dehiscence in one case. The problem rate in eyes receiving prior radiotherapy or surgery was not increased. The hydroxyapatite integrated orbital implant is a well tolerated motility implant without the high rate of extrusion and infection seen with other motility implants. The prosthesis fit may contribute to the tolerance of the implant.

Child↗
PubMed1994

[Iris neovascularization, increased intraocular pressure and vitreous hemorrhage as risk factors for invasion of the optic nerve and choroid in children with retinoblastoma].

A review of 289 eyes enculeated for retinoblastoma to evaluate prognostic factors for involvement of the choroid or optic nerve revealed choroidal invasion in 67 eyes (22%) and optic nerve invasion in 84 eyes (27%) due to retinoblastoma. Intraocular pressure (IOP) > or = 22 mmHg was found in 85 eyes prior to enucleation. A total of 118 eyes (38% showed histopathologic evidence of the development of glaucoma: 90 of them with iris neovascularisation and 28 with angle closure configuration. Patients with elevated IOP, iris neovascularisation and angle closure configuration had a significantly higher risk of optic nerve (P < 0.005) and choroidal (P < 0.002) involvement. On the other hand, optic nerve invasion due to retinoblastoma was significantly more frequent in eyes with elevated IOP (P < 0.02) and iris neovascularisation or angle closure configuration (P < 0.01). Risk factors for choroidal invasion of retinoblastoma were raised IOP (P < 0.04) and iris neovascularisations or angle closure configuration (P < 0.01) (univariant analysis). Raised IOP, iris neovascularisations and vitreous haemorrhage remained significant in the multivariant analysis. This study emphases the importance of IOP, iris neovascularisation and angle closure configuration as risk factors for outspreading invasion due to retinoblastoma.

Adolescent↗
PubMed1993

Uveal metastasis from prostate carcinoma.

BACKGROUND: Although breast and lung cancers account for most metastatic tumors to the uvea, prostate carcinoma metastatic to the uvea is relatively rare. METHODS: The authors reviewed 379 consecutive patients with uveal metastasis referred to the Ocular Oncology Service at the Wills Eye Hospital to determine the frequency of prostate carcinoma as the primary neoplasm. RESULTS: Of 379 consecutive patients with uveal metastasis, the primary tumor was prostate carcinoma in 7 (2% of all patients, 5% of male patients). The mean age at ocular diagnosis was 66 years. In six patients (85%) a prior history of prostate carcinoma was known and the prior history of prostate carcinoma was known and the mean time interval between the diagnosis of the primary tumor and the uveal metastasis was 28 months. All seven patients were found to have active or regressed metastases elsewhere. The choroid was involved in six patients (85%) and the iris in one (15%). Ocular treatment included external-beam radiation therapy in five patients (70%) and episcleral radioactive plaque in two (30%). After a total mean follow-up of 84 months (range, 44-140 months) from the diagnosis of prostate carcinoma, two patients were still alive and five patients have died (mean, 6 months after diagnosis of uveal metastasis). CONCLUSIONS: Prostate carcinoma can metastasize to the uvea and the presence of uveal metastasis is associated with a shorter survival time compared with metastasis to other sites.

Aged↗
PubMed1993

Regression of retinoblastoma after plaque radiotherapy.

A review of 400 consecutive patients with retinoblastoma disclosed that 103 tumors in 103 eyes were treated with solitary plaque radiotherapy. The tumors were from 1 to 16 mm (mean, 7 mm) in basal diameter and from 1 to 8 mm (mean, 4 mm) in thickness. Thirty-one tumors were treated with plaque radiotherapy as initial treatment, whereas 72 tumors were treated with plaque radiotherapy as secondary treatment after failure of other methods. Of the 102 tumors on which adequate follow-up data were available, all responded initially to plaque radiotherapy with tumor regression. Over the mean follow-up of 38 months (range, six to 192 months), 89 tumors (87%) showed persistent regression and 13 (13%) showed tumor recurrence. The recurrence occurred at a mean interval of five months (range, one to 11 months) after plaque radiotherapy. A statistical analysis of tumor size, tumor location, tumor proximity to the optic disk and foveola, presence of vitreous seeds, radioactive plaque diameter, plaque shape, radioisotope, and primary or secondary treatment disclosed no important predictors of tumor recurrence. Carefully selected retinoblastoma, even juxtapapillary and macular tumors and those with localized vitreous seeds, can be successfully treated with plaque radiotherapy.

Brachytherapy↗