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Biomedical subjects

J A Shields

Publications and source records attributed to J A Shields.

At least 199 records · Page 11Linked to original sources
PubMed1996

MRI of orbital hydroxyapatite implants.

Our aim was to use MRI for the postsurgical assessment of a new form of integrated orbital implant composed of a porous calcium phosphate hydroxyapatite substrate. We studied ten patients 24-74 years of age who underwent enucleation and implantation of a hydroxyapatite ball; 5-13 months after surgery, each patient was examined by spinecho MRI, with fat suppression and gadolinium enhancement. Fibrovascular ingrowth was demonstrated in all ten patients as areas of enhancement at the periphery of the hydroxyapatite sphere that extended to the center to a variable degree. The radiologist should aware of the MRI appearances of the coralline hydroxyapatite orbital implant since it is now widely used following enucleation. MRI is a useful means to determine successful incorporation of the substrate into the orbital tissues. The normal pattern of contrast enhancement should not be mistaken for recurrent tumor or infection.

Adult↗
PubMed1996

Imaging in the trilateral retinoblastoma syndrome.

The medical records, CT, and MRI of ten children with trilateral retinoblastoma were reviewed. The intracranial pathology consisted of eight pineal neoplasms and two parasellar lesions, at least seven of the which were calcified. Two lesions demonstrated calcification only (no soft tissue mass) at initial presentation. Hydrocephalus was seen in eight cases, and concurrent or subsequent subarachnoid dissemination was documented in seven. Only one patient is known to be alive at the present time. The imaging features of the midline intracranial tumors mirror those of the ocular neoplasm. As calcification may be the only clue to the presence of the intracranial malignancy, close surveillance of high-risk patients with retinoblastoma with initial CT and follow-up MRI is suggested.

Brain↗
PubMed1996

Ophthalmic features of the organoid nevus syndrome.

BACKGROUND/PURPOSE: The organoid nevus (sebaceous nevus) syndrome is characterized primarily by cutaneous sebaceous nevus, seizures, and epibulbar choristomas. On the basis of ophthalmoscopic and computed tomographic studies, a yellow fundus lesion recently observed in this syndrome has been called a coloboma by some investigators and a choroidal osteoma by others. This study was undertaken to review our personal experience with the organoid nevus syndrome, to review the English language literature on the subject, and to address some misconceptions regarding its ocular manifestations. METHODS: We reviewed the records of patients with the organoid nevus syndrome who were personally evaluated by the investigators. The ocular findings were studied in more detail, with emphasis on the epibulbar and fundus lesions. RESULTS: We identified five patients with the organoid nevus syndrome. Four had a classic sebaceous nevus in the facial and scalp area, and 2 had seizures and arachnoid cysts. All 5 patients had an epibulbar tumor, which proved to be a complex choristoma in one case that was studied histopathologically. A characteristic ophthalmoscopic feature, observed in the 4 patients with clear ocular media, was a flat yellow discoloration of the posterior fundus, of variable size and shape, which appeared to correlate with a dense plaque noted on ultrasonography and computed tomography. In 1 case, histopathologic examination showed that this posterior lesion contained intrascleral cartilage. CONCLUSIONS: Our observations and a review of the literature indicated that the organoid nevus syndrome has varied manifestations. Like the closely related phakomatoses, it often occurs as a forme fruste, without full expression of the syndrome. The most important ocular manifestations are an epibulbar mass, compatible with a complex choristoma, and focal yellow discoloration in the fundus, probably related to intrascleral cartilage.

Adolescent↗
PubMed1996

Choroidal melanoma in an African-American albino.

PURPOSE: To report the rare occurrence of choroidal melanoma in an African-American albino. METHODS: A 68-year-old African-American man with oculocutaneous albinism developed an amelanotic choroidal mass in his left eye. A transvitreal fine-needle aspiration biopsy was performed to confirm the diagnosis, and the patient was treated with iodine 125 plaque radiotherapy. RESULTS: The cytology of the needle biopsy showed spindle cells with nuclear atypia and prominent nucleoli. The cells showed positive immunoreactivity for HMB-45, supporting the diagnosis of choroidal melanoma. CONCLUSION: To our knowledge, this is the first reported case of a choroidal melanoma occurring in an African-American albino.

Black or African American↗
PubMed1996

Acquired neoplasms of the nonpigmented ciliary epithelium (adenoma and adenocarcinoma).

BACKGROUND/PURPOSE: Acquired neoplasms of the nonpigmented ciliary body epithelium (NPCE) are rare, and most information about them has come from single case reports. This study was undertaken to review the authors' experience with a series of patients with acquired neoplasms of the NPCE, to delineate the clinical and histopathologic features of these tumors, and show how they differ from ciliary body melanoma. METHODS: A clinicopathologic review was conducted on acquired tumors of the NPCE that were evaluated by the authors and a review of the English language literature was done. The data from the authors' cases were compared with previously reported cases. RESULTS: The authors had personal experience with nine patients with acquired tumors of the NPCE and found 18 other patients with these tumors in the literature. Of the authors' patients, all tumors were predominantly nonpigmented and were white to light-tan in color. Associated clinical findings included signs of intraocular inflammation in all patients, secondary cataract in eight (89%), and subluxation of the lens in six (67%). Eight of the tumors were managed successfully by local resection and one by enucleation. Histopathologically, the tumors showed considerable variation from patient to patient. Seven tumors were classified as benign adenoma and two as low-grade adenocarcinoma. There was no local recurrence or systemic metastases. Although tumors of the NPCE historically have been misdiagnosed clinically as ciliary body melanoma, our study suggests that they have some characteristic features that severe to differentiate them from melanoma and other ciliary body lesions. In contrast to melanoma, acquired neoplasms of the NPCE are amelanotic and are more likely to have an irregular surface, associated inflammatory signs, to transmit light well during transillumination, and show high internal reflectivity with ultrasonography. CONCLUSION: Acquired neoplasms of the NPCE have characteristic clinical and histopathologic features that should suggest the diagnosis. Due to their anterior location in the ciliary body, local resection (rather than enucleation) is usually the treatment of choice. The visual prognosis is fair, and the systemic prognosis is excellent.

Adenocarcinoma↗
PubMed1996

Congenital neoplasms of the nonpigmented ciliary epithelium (medulloepithelioma).

BACKGROUND: Most reports on intraocular medulloepithelioma have been single case descriptions. The authors reviewed ten patients with intraocular medulloepithelioma, discuss some little known clinical features of this entity, and make diagnostic and therapeutic recommendations. PATIENTS AND METHODS: The records of the authors' patients with histopathologically confirmed medulloepithelioma were reviewed, and the clinical features, diagnostic problems, management, histopathology, and prognosis were assessed. RESULTS: Of the ten patients, nine were children, ranging in age from 2 months to 10 years, and one patient was 58 years of age at the time of clinical presentation. In seven patients, there was a delay in diagnosis, ranging from 3 to 28 months, and four patients underwent surgery for cataract, glaucoma, or other secondary conditions while the tumor was unsuspected. All patients had a nonpigmented ciliary body mass and a notched or subluxated lens, and six had neovascular glaucoma and evident cysts in the mass. The authors' initial management was enucleation in four patients and local resection in six. Of the six patients managed by local resection, five eventually required enucleation, four because of local tumor recurrence and one because of ocular inflammation and discomfort. Pathologically, nine tumors were classified as malignant (5 teratoid, 4 nonteratoid) and one as benign. In one patient (the adult), metastasis to the parotid gland developed. CONCLUSION: Intraocular medulloepithelioma generally occurs in the first decade of life as a nonpigmented ciliary body mass. It has a tendency to cause secondary neovascular glaucoma, a characteristic lens notch and subluxation, and a neoplastic cyclitic membrane. Enucleation is the best treatment for advanced cases. For smaller circumscribed lesions, local resection may be attempted, but such treatment is followed frequently by local recurrence. Although most medulloepitheliomas are cytologically malignant, distant metastasis is uncommon.

Cataract Extraction↗
PubMed1996

The role of magnetic resonance imaging in children with intraocular tumors and simulating lesions.

PURPOSE: To evaluate the role of pre- and post-contrast magnetic resonance (MR) studies in children with intraocular tumors and simulating lesions. METHODS: Patients younger than 12 years of age with the diagnosis of an intraocular tumor or simulating lesion with a thickness greater than 2.0 mm underwent pre- and post-contrast MR studies with surface coil. All post-contrast-enhanced images were performed with fat suppression techniques. RESULTS: There were 40 children with the clinical diagnosis of an intraocular lesion as follows: retinoblastoma (n = 22), Coats disease (n = 5), ciliary body medulloepithelioma (n = 2), primary hyperplastic persistent vitreous (PHPV) (n = 2), retinal capillary hemangioma (n = 3), massive retinal gliosis (phthisis bulbi) (n = 2), uveal melanoma (n = 1), ciliary body leiomyoma (n = 1), retinopathy of prematurity (ROP) with total retinal detachment (n = 1), and post-traumatic retinal gliosis (n = 1). In the authors' series, solid intraocular tumors greater than 2.0 mm in thickness such as retinoblastoma, ciliary body medulloepithelioma, leiomyoma, choroidal melanoma, and retinal capillary hemangioma appeared hyperintense on T1-weighted images and hypointense on T2-weighted images. Secondary serous or exudative retinal detachment, regardless of the underlying etiology (neoplasm, Coats disease, PHPV, phthisis bulbi, ROP), showed hyperintensity of the subretinal space on both T1- and T2-weighted images. Retinal gliosis was hypointense on both T1- and T2-weighted images. On contrast-enhanced T1-weighted images with fat suppression techniques, minimal to marked enhancement was observed in retinoblastoma, medulloepithelioma, retinal capillary hemangioma, leiomyoma, and choroidal melanoma. No enhancement was demonstrated in the subretinal space of Coats disease, PHPV, ROP, and in retinal gliosis. Calcification was identified in 54% of retinoblastoma tumors on MR sequences. Calcification showed low signal intensity on both T1- and T2-weighted images, with lack of enhancement on contrast-enhanced sequences, thus differentiating it from surrounding tumor or tissue necrosis. The associated serous or exudative subretinal fluid secondary to intraocular tumors or simulating lesions did not demonstrate enhancement after contrast administration, therefore differentiating it from the causative lesion. CONCLUSION: Pre- and post-contrast MR studies allowed differentiation of solid intraocular tumors such as retinoblastoma, medulloepithelioma, retinal capillary hemangioma, leiomyoma, and choroidal melanoma from intraocular lesions with primary retinal detachment such as Coats disease, PHPV, massive retinal gliosis (phthisis bulbi), ROP, and associated subretinal fluid or hemorrhage. Heterogeneity within retinoblastoma suggests foci of tumor necrosis and/or calcification. The various solid intraocular tumors were not reliably differentiated from one another based on MR features.

Child↗
PubMed1996

Transpupillary thermotherapy in the management of choroidal melanoma.

BACKGROUND: Several methods of treatment have been used for choroidal melanoma. The purpose of this report is to evaluate the effectiveness of transpupillary thermotherapy using near-infrared radiation to treat choroidal melanoma. METHODS: A prospective study was conducted to evaluate the clinical features, treatment results, and complications of patients with choroidal melanoma who were treated with transpupillary thermotherapy delivered over one to four sessions and followed for at least a 6-month period. All treated tumors had either documentation of growth or ophthalmoscopic risk factors for future growth and/or metastasis. RESULTS: There were 17 patients with choroidal melanoma treated with transpupillary thermotherapy. The mean tumor size before treatment was 6.6 mm in base and 3.0 mm in thickness. The tumor margin was a mean of 2.3 mm from the optic disc and 2.7 mm from the foveola. Seven tumors (41%) touched the optic disc margin and three (18%) were under the fovea. The tumor responded to treatment in all patients, with a decrease in thickness and resolution of associated subretinal fluid. At a minimum of 6 months of follow-up, the mean tumor thickness was 1.7 mm, and the tumor site was a residual chorioretinal scar with partial visibility of the sclera in all patients. Despite the proximity to the optic disc and foveola, the final visual acuity was the same or improved in ten eyes (59%) and decreased in seven (41%). The improved vision was due to resolution of subfoveal fluid, whereas the decreased vision was primarily the result of treatment in the fovea with ultimate retinal vascular occlusion or preretinal traction. Although long-term follow-up is not yet available, there were no patients with tumor recurrence or tumor metastases. CONCLUSIONS: This preliminary study demonstrates that transpupillary the thermotherapy appears to be an effective treatment for selected small choroidal melanomas and may be a particularly useful modality for treating those tumors near the foveola and optic disc. Longer follow-up is necessary to assess for local recurrence and the impact of treatment on survival.

Adult↗
PubMed1996

Atypical retinal astrocytic hamartoma diagnosed by fine-needle biopsy.

BACKGROUND: Retinal astrocytic hamartoma and retinoblastoma may be very similar clinically, and their differentiation in atypical cases can be difficult, even with the use of ancillary methods such as fluorescein angiography, ultrasonography, and computed tomography. To the authors knowledge, fine-needle aspiration biopsy has not been used to diagnose astrocytic hamartoma in such cases. PATIENTS AND METHODS: A 7-week-old boy had a minimally calcified retinal mass in the macular area of the left eye associated with an extensive secondary retinal detachment. The differential diagnosis included retinal astrocytic hamartoma and retinoblastoma. A transvitreal fine-needle aspiration biopsy was performed. RESULTS: The cytology of the needle biopsy showed benign spindle and stellate cells, which were compatible with glial cells. The lesion had immunoreactivity for glial fibrillary acidic protein, further supporting the diagnosis of astrocytic tumor. CONCLUSION: Fine-needle aspiration biopsy is diagnostically useful in unusual cases where the differential diagnosis between retinoblastoma and astrocytic hamartoma is difficult.

Astrocytes↗
PubMed1996

Bilateral primary uveal melanoma. Bad luck or bad genes?

BACKGROUND: The occurrence of bilateral primary uveal melanoma has been assumed to be a rare, random event . Bilaterality of a primary cancer is suggestive of an inherited cancer predisposition. The authors therefore evaluated patients with bilateral primary uveal melanoma for such cancer predisposition. METHODS: The charts of 4500 patients with uveal melanoma were reviewed for the presence of bilaterality. The clinical profile of patients with bilateral primary uveal melanoma was studied. The presence of ocular melanocytosis, familial atypical mole and melanoma syndrome, neurofibromatosis type 1, cutaneous melanoma, familial uveal melanoma, Li-Fraumeni syndrome, and second primary cancers also was investigated. RESULTS: Of 4500 patients with primary uveal melanoma, 8 (0.18%) were identified to have bilateral primary uveal melanoma. Using the annual incidence rate (Shammas and Watzke) and normal approximation to the binomial, the expected number of patients with primary bilateral uveal melanoma in the authors' series was calculated to be less than one person. Observation of eight patients with bilateral primary uveal melanoma represented greater than expected occurrence (P<0.0001). The mean age at diagnosis in the first eye was 56 years. The interval between the diagnosis of uveal melanoma in the two eyes ranged from 2 to 32 years (median, 10.5 years). Two patients had bilateral ocular melanocytosis. Ocular melanocytosis was more common (2/8, 25%) in patients with bilateral uveal melanoma compared with those with unilateral uveal melanoma (60/4492, 1.3%). This difference was statistically significant (P = 0.001). No relation to familial atypical mole and melanoma syndrome, cutaneous melanoma, neurofibromatosis type 1, familial uveal melanoma, second primary cancers, or Li-Fraumenni syndrome was observed. CONCLUSIONS: Bilateral primary uveal melanoma occurs more frequently than expected by chance, and may be associated with ocular melanocytosis. In the authors' series, there was no clinical evidence of an inherited genetic predisposition for bilateral primary uveal melanoma. Unidentified germ-line mutations may be involved in pathogenesis of bilateral uveal melanoma.

Adult↗
PubMed1996

New treatment modalities for retinoblastoma.

The management of retinoblastoma has evolved tremendously for the past century, and recently there is a trend toward focal conservative treatments. This trend is due primarily to the earlier detection of the disease when the tumors are in a smaller stage of development as well as to advanced, more focused treatment modalities. Enucleation is still used for advanced retinoblastoma, especially when there is a concern that there may be invasion of the optic nerve, choroid, or orbit. The hydroxyapatite implant has provided improved cosmetic rehabilitation of the socket after enucleation. External-beam radiotherapy continues to be an important method of treating advanced retinoblastoma, especially when there is diffuse vitreous seeding. Plaque radiotherapy is a useful tool for controlling medium or small retinoblastomas, especially tumors with focal vitreous seeding or those that recur after other methods have failed. Cryotherapy and photocoagulation provide excellent control of small tumors, and advanced laser delivery systems have improved the visualization and ease of treatment of retinoblastoma. Thermotherapy and chemothermotherapy are the newest focal methods that are showing promising results for small to medium-sized retinoblastoma. Recent developments with chemotherapy regimens have allowed dramatic control of intraocular retinoblastoma, and they play an important role in the initial management of many cases.

Combined Modality Therapy↗
PubMed1996

New treatment modalities for uveal melanoma.

The management of uveal melanoma has evolved tremendously for the past century, and more recently there is a trend toward more focal conservative treatment. Enucleation is still performed for large uveal melanoma when there is no hope for useful vision with conservative treatment. Plaque radiotherapy is particularly recommended for medium- or small-sized uveal melanoma. Special custom-designed plaque radiotherapy can be used for iris, ciliary body, or juxtapapillary choroidal melanoma. Charged-particle irradiation constitutes an alternative treatment modality for posterior uveal melanoma. However, charged-particle therapy is limited by the availability of appropriate therapeutic facilities. Local tumor resection using lamellar sclerouvectomy is mainly suitable for selected iris, ciliary body, or anterior choroidal tumors with smaller basal dimension and greater thickness. Ablative laser photocoagulation is indicated for very selected cases of small posterior choroidal uveal melanoma. Combined plaque radiotherapy with indirect ophthalmoscope laser therapy appears to be a more effective local tumor treatment plan than plaque radiotherapy alone. Transpupillary thermotherapy is the newest modality used as primary treatment or as complementary method to brachytherapy for treatment of selected choroidal melanomas. Hyperthermia with infrared irradiation below photocoagulation level produces tumor necrosis with few ocular complications. Based on the published ophthalmic literature, it seems that enucleation carries the same survival prognosis as each of the conservative treatment modalities.

Combined Modality Therapy↗
PubMed1996

Metastatic tumours to the conjunctiva: report of 10 cases.

AIMS/BACKGROUND: Ten patients with metastatic tumours to the conjunctiva and the clinical aspects of this rare form of ocular metastasis are described in this study. METHOD: All patients with ocular and adnexal metastatic tumours referred to an ocular oncology service were reviewed and those having conjunctival metastases were studied for the site of their primary tumour, clinical features, and treatment of the conjunctival tumour, associated ocular and systemic findings, and the patients' outcome. RESULTS: The primary malignancy was carcinoma of the breast in four, lung cancer in two, laryngeal carcinoma in one, cutaneous melanoma in two, and unknown in one patient. The conjunctival metastases appeared after the primary tumour over a mean period of 44 (8-130) months. They were solitary in eight cases, located in bulbar conjunctiva in six, palpebral conjunctiva in two, and in limbus and forniceal conjunctiva in one patient each. The tumour was yellow in colour in seven patients, red in two, and brown in one. Eight patients also had metastases to other ocular structures. Seven patients received external beam radiotherapy to the affected eye, two were managed by excisional biopsy, and one with chemotherapy. The mean survival after the diagnosis of conjunctival metastasis was nine (range 2-26) months. CONCLUSION: Metastatic tumours to the conjunctiva appear at an advanced stage of the systemic disease when there are other ocular and organ metastases. The presence of a conjunctival mass in a patient with a prior systemic cancer should alert the ophthalmologist to the possibility of a conjunctival metastasis and evaluation should be pursued.

Adult↗