History
A 62-year-old black female, referred by her general physician, presented for an eye examination to rule out treatable retinopathy secondary to systemic hypertension and diabetes.
Diagnostic Data
Her best-corrected acuity following refraction was 20/25 O.U. at distance and near. External examination was normal with no evidence of afferent pupillary defect. The confrontational visual field was normal.
Anterior segment structures were normal in both eyes, and applanation intraocular pressures measured 15mm Hg O.U.
The dilated fundus examination uncovered mildly asymmetric and increased cup-to-disc ratios. The significant fundus findings are illustrated in the photographs.
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| The patient presented with this retinal appearance (O.D. left, O.S. right). |
How would you approach this case? Does this patient require additional tests? What is your diagnosis? How would you manage this patient? What is the likely prognosis?
Discussion
Additional testing for this case included ophthalmic photography and MRI neuroimaging with and without gadolinium. Cerebrospinal fluid examination is helpful but rarely used. If the suspected etiopathology is inflammatory or infectious, blood tests such as angiotensin-converting enzyme, Lyme titer, rapid plasma reagin (RPR) and fluorescent treponemal antibody (FTA) absorption should be considered.
The diagnosis in this case is Rathke"s cleft cyst (RCC). Arachnoidal cysts are typically serous cavities lined by neuroepithelium. They have many causes, including trauma and inflammation. Lined with columnar or cuboidal epithelium of ectodermal origin, RCCs usually contain mucoid material and can be found in 13% to 22% of normal pituitary glands.1
Many RCCs, as in this case, are asymptomatic, occupying silent compartments.1-4 They also have the capability to produce variable symptoms by mass effects on adjacent brain structures. Some suprasellar cysts apparently arise as congenital anomalies in the floor of the third ventricle.
In children, developmental sellar cysts, a form of primary empty sella, may be associated with growth hormone deficiency or other pituitary deficiencies, including precocious or delayed puberty and diabetes insipidus.1,3 In the "empty sella syndrome," such intrasellar cysts communicate with the subarachnoid space. Intrasellar cysts are apparently common findings in anatomic studies. Other cysts arise in the sella itself and are variably termed cysts of Rathke"s pouch, epithelial cysts or colloid cysts, depending on the anatomic disposition and histologic characteristics.1-4
Adult patients are often asymptomatic. But when symptoms do occur, they include headaches (50%), blurred vision (40%) and seizures (40%); some 15% of adults and children older than five years complain of diplopia.1-5 Effects on vision are variable, and while some patients have no manifestations in visual acuity, others have symptomatic or asymptomatic deficits in the visual field. In one retrospective study, visual field defects were documented in eight out of 12 symptomatic patients.5
Rathke"s cleft cysts originate in the vestigial epithelial remnants of the primitive stomodial ectoderm, which normally forms the anterior, intermediate and pars tuberalis lobes of the pituitary gland. Cysts of the residual stomodial lumen (Rathke"s cleft) are found in as many as 22% of autopsies and, with the advent of CT and MRI neuroimaging, are being discovered in increasing numbers.4 These cysts may be asymptomatic or cause headache, amenorrhea, hypopituitarism, diabetes insipidus, galactorrhea and vision loss. When they present in a chiasmal syndrome, they require surgical decompression without radiation therapy.3
This patient underwent surgical decompression and recovered 95% of her lost visual field.
1. Yoon JW, Jo SK, Cha DR, et al. A case of Rathke"s cleft cyst inflammation presenting with diabetes insipidus. Korean J Intern Med 2001 Jun;16(2):132-5.
2. Glaser JS. Topical diagnosis: the optic chiasm. In: Tasman W, Jaeger EA. Duane"s Clinical Ophthalmology on CD-ROM 2001 Edition. Philadelphia: Lippincott Williams & Wilkins.
3. Sumida M, Migita K, Tominaga A, et al. Concomitant pituitary adenoma and Rathke"s cleft cyst. Neuroradiology 2001 Sep;43(9):755-9.
4. Isono M, Kamida T, Kobayashi H, et al. Clinical features of symptomatic Rathke"s cleft cyst. Clin Neurol Neurosurg 2001 Jul;103(2):96-100.
5. Mukherjee JJ, Islam N, Kaltsas G, et al. Clinical, radiological and pathological features of patients with Rathke"s cleft cysts: tumors that may recur. J Clin Endocrinol Metab 1997;82(7):2357-62.
