Ординатура / Офтальмология / Английские материалы / Clinical Ophthalmic Echography_Harrie_2008

SG is a 78-year-old woman who had a history of mild dry macular degeneration bilaterally. Her medical history included a history of breast cancer 8 years prior to presentation that had been in remission after a mastectomy, radiation therapy, and a course of chemotherapy. She was seen for a routine annual examination by her ophthalmologist, who noted a raised grayish lesion in the right temporal fundus near the equator. She had no subjective symptoms due to this process but the clinician referred her for echography to rule out a neoplasm.

A-scan revealed a 3.1-mm lesion near the temporal equator with moderately irregular internal reflectivity, including a high internal spike (Fig. 289). The differential included an eccentric subretinal disciform lesion, metastatic tumor to the choroid, and a choroidal hemangioma.

The patient was reevaluated by her primary care physician with a systemic workup, including a bone scan that did not show evidence of metastatic tumor. She was scheduled for repeat ophthalmic examination and echography 2 months after the initial exam. Clinical evaluation showed no apparent change in the lesion and ultrasound measured the same thickness and demonstrated no change in internal reflectivity. She was scheduled for another follow-up exam 3 months later, and again no change in thickness or reflectivity was noted. The dormancy of this lesion was most consistent with a gliotic subretinal disciform scar and it was planned to follow her on a biannual basis.

The other major differential considerations in the evaluation of possible choroidal metastatic disease include hemangiomas and atypical melanomas. Choroidal hemangiomas have a microscopic

structure that is honeycomb-like with multiple blood-filled cystic spaces (Fig. 290). As the sound beam travels through this tissue, it is reflected by the septae between the blood-containing cavities. If the cystic spaces were larger, the reflectivity of the A-scan spikes would become lower as the sound wave was propagated through the homogenous blood. This does occur in orbital cavernous hemangiomas. However, the spaces in hemangiomas of the choroid are small enough relative to the sound beam that there is not enough time for the reflectivity to become very low before it strikes another septum and results in a high reflective spike. Therefore, the A-scan characteristics of a choroidal hemangioma are relatively high spikes with a regular structure (Fig. 291).

FIG. 289. A-scan of an eccentric disciform lesion (arrows)

TA is a 52-year-old man who complained of some visual distortion in his right field of vision for several weeks. He was seen by an ophthalmologist who documented visual acuity of 20/30-2 OD and 20/20 OS. Ophthalmoscopic examination found a yellow-orange elevated lesion just below the macula. Fluorescein angiography was performed and demonstrated mottled leakage of dye within the lesion that increased over several minutes. These findings were consistent with a choroidal hemangioma but an amelanotic melanoma or metastatic tumor could not be eliminated completely.

FIG. 292. B-scan of a choroidal hemangioma (arrow)

FIG. 293. A-scan of a choroidal hemangioma (arrows)

B-scan showed a dome-shaped highly reflective lesion (Fig. 292). A-scan demonstrated high, regular internal reflectivity (Fig. 293) that was very consistent with a choroidal hemangioma. The patient was referred for photodynamic therapy (PDT) by a retina specialist with a good response and resolution of the visual distortion.

Occasionally, a hemangioma will show an atypical pattern of internal reflectivity. This makes the distinction from a metastatic lesion much more difficult.

GS is a 61-year-old man with a history of colon cancer who presented with a shadow just below the center in his left eye for a month. He presented to his optometrist who found vision of 20/20-1 OD and 20/25-2 OS. Fundus examination revealed an orange coloration of the paramacular area, but a distinct mass was not appreciated. The patient was referred for fluorescein angiography that demonstrated diffuse leakage from the choriocapillaris.

A-scan demonstrated mostly medium high spikes with some irregularity (Fig. 294). No spontaneous vascularity was noted. The differential diagnosis included metastatic tumor to the choroid and choroidal hemangioma. The patient was referred to his primary care doctor for systemic evaluation. Repeat colonoscopy showed no recurrence of the primary tumor and the metastatic workup was negative. The lesion was followed for several months without evidence of growth. He ultimately opted for treatment with PDT.

FIG. 294. A-scan of an irregular choroidal hemangioma (arrows)

Another orange-pigmented lesion included in the differential diagnosis of metastatic tumor is amelanotic melanoma. Choroidal melanomas are usually darkly pigmented but about 10% have lesser degrees of pigment that can result in their clinical confusion with other lesions. Echography is very valuable in distinguishing these entities from each other. The B-scan appearance is about the same for choroidal hemangioma, metastatic tumor, and amelanotic melanoma, but the internal reflectivity patterns on A-scan are very distinctive. The following table compares these reflectivity patterns:

Systemic non-Hodgkin’s lymphoma can rarely present as an intraocular tumor. It may invade the choroid as a solitary orange mass or as diffuse choroidal thickening. Central nervous system (CNS) lymphoma has a much higher probability of ocular and orbital involvement than the systemic form. It usually causes multiple punctate white dots in the choroid with vitreous cells, but may also invade the optic nerve with fulminate disc and peripapillary edema. An older patient with chronic vitritis should always be evaluated for the possibility of CNS lymphoma with neuroimaging studies.

RT was an 82-year-old man who noted blurred vision in both eyes for several weeks. He was seen by an optometrist who documented vision of 20/80 OD and 20/100 OS. Slit-lamp examination was unremarkable except for mild nuclear sclerotic cataracts. Fundus examination showed bilateral optic disc edema (Fig. 295). The patient was referred for neurological workup and an MRI scan was obtained. It showed no abnormalities in the brain, but some enhancement of both optic nerves with gadolinium injection (Fig. 296).

Echography showed thickening of the both optic nerves, with the right measuring 4.73 mm and the left 6.98 mm (Fig. 297). There was a negative 30° test bilaterally that ruled-out increased optic nerve

sheath fluid and was suggestive of cellular infiltration of the nerves.

Lumbar puncture was performed and a few large B cells were found on microscopic examination of the spinal fluid. The diagnosis of CNS large cell lymphoma was made and the patient was referred for radiation therapy. His vision improved to 20/30 OD and 20/40 OS with almost total resolution of the optic disc swelling. Repeat echography verified reduction of the optic nerve thickness. He remained in remission for several months but then the lymphoma recurred and he expired shortly afterwards.

It is much less common for systemic nonHodgkin’s lymphoma to involve ocular tissue, but infiltration of the uveal tract is the usual route of invasion when it does invade the eye.

KE is a 62-year-old man who presented to his ophthalmologist with the complaint of decreased vision in his right eye over several weeks. He had a history of systemic lymphoma that had been treated 18 months previously, resulting in remission. Examination found the visual acuity in his right eye to be 20/100 and his left eye 20/30. The slit-lamp examination was unremarkable but evaluation of the fundus demonstrated a yellow-orange diffuse thickening of the posterior pole.

Echography revealed choroidal thickening (Figs. 298 and 299). He was diagnosed as having posterior scleritis and started on high-dose oral prednisone. His vision improved and the echographic findings

FIG. 298. A-scan of lymphoma of the choroid (arrows).

FIG. 299. B-scan of the lesion (arrow)

showed resolution of the thickening. However, the symptoms and signs of infiltration of the posterior pole recurred in a few weeks and he was found to have infiltration of the liver and spleen on CT scan. A lumbar puncture was performed and was negative for malignant cells. He died shortly after and autopsy demonstrated non-Hodgkin’s lymphoma.

Inflammatory infiltrates, such as in posterior scleritis, can simulate amelanotic neoplastic lesions. The sclera becomes thickened with edema of adjacent tissue, such as the choroid and subtenon’s space. This condition is usually quite painful but in cases with lesser degrees of pain, the lesion can be confused with a tumor.

DF is a 26-year-old man who complained of mild aching behind his left eye and some blurring for several weeks. He presented to an optometrist who documented vision of 20/20 OD and 20/30+2 OS. Slit-lamp examination revealed mild injection of the conjunctiva of the right eye and a clear anterior chamber without flare or cells. Fundus examination revealed a creamy yellow lesion temporal to the macula. Echography demonstrated a dome-shaped lesion on B-scan with low-to-medium irregular reflectivity on A-scan with some high reflective scleral thickening (Figs. 300 and 301). The differential diagnosis included an inflammatory choroidal edema secondary to posterior scleritis. He was treated with topical

FIG. 300. A-scan of nodular postscleritis (arrows)

FIG. 301. B-scan of the same area (arrow)

steroids and systemic nonsteroidal anti-inflamma- tory medication with resolution of his symptoms and the fundus lesion over 2 weeks.

Another nonpigmented malignant tumor of the fundus is retinoblastoma. The average age of patients with this lesion is under 2 years but they have been reported in adults. Even though it is rare, the differential diagnosis of an amelanotic mass in an adult should include retinoblastoma. Biswas et al.62 reported on three cases of adults with retinoblastomas and summarized 20 cases from the literature. Two of their cases were noncalcified. Most of the patients reported in the literature had posterior lesions but this tumor can rarely present peripherally.

AH is a 35-year-old man who presented to his ophthalmologist with the complaint of floaters and reduced vision in his right eye for several months. Examination documented vision of 20/40 in that eye and 20/20 in the left eye. Slit-lamp examination revealed trace cells in the anterior chamber and an inferior sector cataract. Fundus examination showed 1+ vitreous cells and what appeared to be inflammatory debris near the 6:00 pars plana.

B-scan demonstrated a probable mass in the inferior peripheral fundus (Fig. 302). Internal reflectivity was difficult to characterize because of the very peripheral location of the lesion. Several probable calcium flecks were detected within the lesion on B-scan. The differential diagnosis included melanoma, medulloblastoma, and other solid tumors.

A needle biopsy was performed and malignant cells consistent with retinoblastoma were documented on cytological analysis. The patient elected to have his eye enucleated and a retinoblastoma was confirmed. Although retinoblastoma is rare in adults, it is the most common malignant ocular tumor in children, where it often presents as leukocoria.

The role of echography in the workup of leukocoria is invaluable. The various entities in the differential diagnosis that can be elucidated by echography include retinoblastoma, medulloepithelioma, toxocara, Coats’ disease, retinal detachment (including that seen in incontinentia pigmentosa and Norrie’s disease), persistent hyperplastic primary vitreous (PHPV), and retinopathy of prematurity (ROP).

The most serious entity in the differential of leukocoria is retinoblastoma, which is a potentially

life-threatening tumor for which timely diagnosis and treatment are mandatory. The prognosis for survival has improved dramatically with modern treatment, including radiation and chemotherapy, with a survival rate approaching 95% in developed countries. Unfortunately, these tumors are a significant cause of mortality in developing countries because many patients are not seen for medical care until relatively late in the progress of the disease. The incidence of retinoblastoma is about the same in blacks and Asians as among Caucasians. This is opposed to choroidal melanomas that are much more common among fair-skinned populations in a ratio of 18:1.63

Ultrasound has made the challenging evaluation of leukocoria a much easier task than in the past.

FIG. 302. B-scan of peripheral retinoblastoma in an adult (arrow)

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The ability of echography to detect calcium is the major differential feature that enables the diagnosis of retinoblastoma with a 98% degree of accuracy

Case Study 166. Retinoblastoma in an Adult

when calcification is present. It is estimated that about 90% to 95% of these tumors contain calcium that is often scattered in clumps within the tumor.