Ординатура / Офтальмология / Английские материалы / Orbital Tumors Diagnosis and Treatment_Karcioglu_2005

and prolonging life. The median survival is 18 to 24 months, but some patients may experience longer survivals.37 Treatment of metastatic breast cancer will usually involve hormone therapy and/or chemotherapy with or without trastuzumab (Herceptin). Radiation therapy and/or surgery may be indicated for patients with limited symptomatic metastases. The rate of regression after palliative radiotherapy of orbital lesions has been 60 and 79% in different series.37,50,51

Hormone therapy should generally be considered as initial treatment for a postmenopausal patient with newly diagnosed metastatic disease if the patient’s tumor is ER positive, PR positive, or ER/PR unknown. Hormone therapy is especially indicated if the disease involves only bone and soft tissue and the patient either has not received adjuvant antiestrogen therapy or has been off such therapy for more than a year. Therapy with tamoxifen has been reported to reduce eyelid and orbital metastases of carcinoma of the breast.52 In patients whose tumors overexpress HER2-neu, administration of Herceptin as a single agent resulted in a significant response rate. Patients whose tumors have progressed despite hormone therapy are candidates for chemotherapy with antimetabolites. Patients with EP/PR-negative tumors and those with visceral metastases are also candidates for chemotherapy.

Miscellaneous Primary Sites

According to different series, the other common cancers metastatic to the orbit include lung (Figure 24.4),53–56 prostate (Figure 24.5),57,58 and hepatic carcinoma (Figure 24.6).59–62 Because of the occult lesion and a symptomatic growth of the primary tumor, orbital metastasis may be the first manifestation of dis-

seminated diseases in 20% of cases.4,6 Many patients have a fulminant course with short survival.

In patients with prostate carcinoma, the diagnosis of metastastic orbital disease is facilitated by the demonstration of osteoblastic and/or osteolytic bone lesions that are associated with pain. In cases of primary manifestation of the disease, confirmation is provided by the measurement of prostate-specific antigen (PSA) in serum or the expression of the same antigen in tissue sections from the metastatic tumor.17,63

Hepatocellular carcinoma is the most frequent metastatic orbital tumor in Japan, but it is rarely seen in Western countries.16 The patients are predominantly males with an average age of 56 years.16 Metastasis to the orbit is usually associated with advanced disease and early mortality; the mean survival after diagnosis is about one year. In a majority of the cases, the proptosis is associated with pain because of early periosteal involvement. The differential diagnosis of painful proptosis should include malignant schwannoma, adenoid cystic carcinoma of the lacrimal gland, and perineural invasion of the orbit by cutaneous squamous cell carcinoma.64–66 FNAB material is usually sufficient for diagnosis, particularly if enough tissue is recovered for immunohistologic chemical stains. Positive stainings of bile canaliculi with polyclonal carcinoembryonic antigen (CEA) marker confirms the diagnosis of hepatocellular carcinoma. -Fetoprotein (AFP) has been reported to be positive in about 80% of hepatocellular carcinomas.67

Metastatic melanoma of the orbit may be seen in several clinical settings.68–71 Most frequently, the patient has had a cutaneous melanoma excised, or an active, nonocular melanoma (Figure 24.7). Rarely, a history or clinical signs of a spontaneously regressed

2 8 6

A

B

P A R T F O U R : S E C O N D A R Y T U M O R S O F T H E A D U L T O R B I T

any body location in which the origin is not identified clinically (Figure 24.2). This situation is known as “carcinoma of unknown primary site” (CUPS) or occult primary malignancy.

The minimal criteria to define CUPS include biopsy of the tumor, complete physical examination, chest x-ray, chest and abdominal CT/MRI, complete blood cell count, urinalysis, and examination of the stool for occult blood.95 Most instances of CUPS are adenocarcinomas or undifferentiated tumors. The majority of the patients with CUPS are over age 60.

The pathologist plays a pivotal role in the identification of the primary tumor. Immunohistochemical studies, histochemistry, polymerase chain reaction sequencing, chromosomal analysis, and electron microscopy may provide useful information to confirm or rule out certain tumors.96,97 A favorable group for therapy has been identified in patients younger than 50 years, with elevated serum levels of human chorionic gonadotropin (hCG) and AFP, presence of neurogranules, and rapid growth rate.

The overall prognosis of CUPS is poor with a median survival of about 6 months. Tumors of the lung, breast, prostate, and thyroid represent approximately 15% of CUPS.98,99 CUPS in which the cell type is identified are treated with standard chemotherapy and hormonal therapy regimens already indicated for such tumors. In the remaining cases, several combined protocols have been used but without much success.99

C

FIGURE 24.7. (A,B) Cutaneous melanoma metastatic to the orbits bilaterally. The predominant tumor load was in the left orbit, and, therefore, the left eye appears to be more proptotic. (B) The extraocular motility of the right orbit was full at the time of the CT scan. Inset: Melanoma cells obtained with FNAB. (C) Enlarged, melanoma-laden, left axillary lymph nodes.

bladder,80 genital organs,81,82 and soft tissue tu- mors.83–87 Carcinoid tumors of the orbit may be primary or metastatic. Metastatic carcinoid tumors to the orbit are characterized by slow growth, circumscribed appearance, and long survival after local88–94 surgical excision. Surgical removal of carcinoid metastatic in the orbit is one of the few indications for surgery because of longer survival.

Metastatic Cancer from Unknown Primary Site

In 10% of metastastic orbital tumors, the origin of the primary tumor remains unknown at the time of diag- nosis.13–15 This rate represents approximately 2.5 to 3.5% of orbital metastases, which is similar to the percentage of histologically documented carcinomas in

Paraneoplastic Orbital Syndrome

Paraneoplastic syndromes with ocular and adnexal involvement are rare. In general, paraneoplastic syndromes are seen in less than 1% of patients with cancer.

Ocular muscle palsy and ptosis may occur without extraocular muscle infiltration due to neuromuscular disorders associated with cancer.95 Patients with small-cell lung cancer may develop antibodies to prevent neuromuscular transmission resulting in a myas- thenic-like syndrome (Lambert–Eaton myasthenic syndrome).100 Other malignancies that may produce similar signs and symptoms include renal cell carcinoma, bronchial carcinoma, lymphoma, malignant thymoma, and transitional cell carcinoma of the bladder.

A rare clinical presentation, apparently not related to direct tumor invasion, has been observed in patients with seminoma and in one patient with paran-glioma.101–104 This unusual syndrome might present with bilateral nonspecific inflammation or Graves-like orbitopathy and thickening of the four extraocular rectus muscles. The mechanism of this disorder is unknown and has been associated with elevated serum levels of hCG. In one case, histo-

pathologic examination of the orbit did not reveal any evidence of tumor infiltation.103 Regression of signs and symptoms has been observed after excision of the primary tumor and in response to corticosteroids. Retinal abnormalities ranging from atrophy to hypopigmentation have been reported in lung cancers and other types of malignant disease.105,106 Since orbital metastases often take place during advanced stages of a malignant process, it is advisable to keep the possibility of retinal dysfunction in mind and examine the patient accordingly.

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The list comprising the benign orbital tumors, tumorlike conditions, and cysts of the pediatric orbit is long (Table 25.1).1–7 However,

many lesions on this list are rare conditions that are seldom encountered even in pediatric ophthalmology referral centers. The more commonly seen benign space-occupying lesions in the pediatric orbit include choristomatous lesions, hamartomas, vascular teratomatous lesions (capillary and cavernous hemangioma, lymphangioma, etc.), benign histiocytic lesions, fibro-osseous lesions, neural tumors, cephaloceles, and miscellaneous cysts, which can be either congenital or acquired. Although any tumor or tumorlike condition may show degenerative changes and present as a cystic lesion clinically, the common feature of all true cysts is a wall containing a cellular lining. This chapter primarily covers congenital orbital tumors and tumorlike conditions including dermoid, dermolipoma, teratoma, cephalocele, and congenital and other cysts. Other frequently encountered pediatric tumors are detailed elsewhere in the book (see Chapters 14, 15, 16, 17, and 27).

Hamartoma is a tumorlike proliferation of tissues that normally exist at a given body location. The best examples of orbital hamartomas are the vascular hamartomatous lesions, which are composed of vascular elements including capillary endothelial cells, distended or collapsed cavernous blood, and lymph vessels, and tortuous arterial and venous channels with or without anastomoses. Other examples of hamartomatous orbital tumors are neurofibroma and lipomatous hamartoma.8 In contrast, choristoma is a tumorlike proliferation of tissues that are not normally present at a given body location. The most commonly encountered example of orbital choristoma is the dermoid.7

DERMOID

Dermoids, which present with many varieties, result from the entrapment of epithelial structures at the site of closure of fetal fissures. Superficial dermoid cysts occur subcutaneously anterior to the orbital septum or immediately posterior to it within the anterior orbit. If the cyst wall is made of epidermis without der-

mal tissues, the lesion is classified as an epidermoid cyst. These cysts are occasionally lined by conjunctival or pseudostratified respiratory epithelium.9 The superficial lesions must be distinguished from deep orbital dermoids, which are usually rounded, encapsulated tumors filled with fatty materials, keratin, and dermal structures such as hair particles. Histopathologically, the dermoid wall is lined by keratinizing squamous epithelium with dermal appendices including hair follicles and sebaceous and ecrine glands.10

Dermoids are seen in the orbit, the eyelids, and the periocular and periorbital areas (Figure 25.1).11–13 Orbit and eyelid dermoids develop as cystic lesions (in contrast to the solid dermoids of the cornea and conjunctiva). Whether solid or cystic, dermoid is a common lesion which accounts for approximately 25% of all orbital space-occupying lesions and 75% of all cystic space occupying lesions in the orbit.9 In another study, it was reported that dermoids consist of approximately 50% of all orbital and periorbital lesions in individuals under the age of 18.9,14

Rarely, dermoids at the frontozygomatic suture may develop dumbbell-shaped lesions partially within the orbit and partially extending into the temporal fossa (Figure 25.2).13,15 Unusually large superior orbital dermoids, particularly those that leak and create granulomatous reactions within adjacent soft tissues, may erode the bone and extend into the frontal sinus or the cranium (Figures 25.3 and 25.4).16

Dermoid cysts are surrounded by a thin wall made of keratinizing, stratified squamous epithelium. The cyst wall contains skin appendages, including hair follicles surrounded by sebaceous glands, sweat glands, and blood vessels. The lumen of the cyst contains a mixture of keratin and fatty glandular secretions and may also contain clumps of hair. The presence of dermal appendages and hair differentiates the dermoid from the epidermoid, which is lined by squamous epithelium but does not contain any other tissue elements of skin in its surrounding wall. The current understanding is that dermoids develop as a result of the entrapment of surface epithelium. Frequently, they occur at bony fusion sites, particularly at the frontozygomatic sutures; other common sites for dermoids are found near the frontonasal and frontolacrimal sutures.

TABLE 25.1. Benign Orbital Tumors and Tumorlike Lesions

of Children.

From a clinical standpoint, dermoids can be divided into the superficial type (found in the eyelids or periorbital skin) and the deep type that is found within the orbit proper posterior to the septum (Figures 25.1 and 25.5). Dermoids are usually unilateral without any predilection to laterality or to the gender or race of the patient. Although these lesions are congenital, only one fourth are clinically evident at birth; they are more often discovered during the first year of a child’s life.7 Most of the time, they are discovered accidentally during childcare activities. Dermoids may also present as

foci of acute inflammation with swelling, erythema, and tenderness. Tenderness is caused by foreign body inflammatory reaction secondary to the leakage of the keratin contents of the dermoid cyst. The signs and symptoms vary with the location and the size of the lesion. Deep orbital dermoids remain symptomless for a longer period of time and may present in adolescence or early adulthood. There is slow occurrence of progressive displacement and/or proptosis of the globe. Less frequently, some dermoids rupture and create cutaneous fistulas.17 If the deep orbital dermoids reach a sufficient size, they may cause diplopia secondary to displacement of the globe and/or oculomotor palsies. Superiorly located dermoids are known to erode the bone of the orbital roof and extend into the frontal sinus and/or the cranium (Figure 25.4).18 Since the dermoids are soft lesions, they rarely cause compressive symptoms such as choroidal folds, venous congestion, and optic neuropathy.19 Imaging studies should include computed tomography (CT) and magnetic resonance (MR); B-scan ultrasonography is also useful in anteriorally located lesions.20,21 Depending on the size, location, and the nature of the intraluminal content, imaging findings may vary; however, most of these lesions present as well-delineated, thin-walled cysts with nonenhancing lumen. CT shows a well-circumscribed cystic mass of low, sometimes negative density due to the presence of lipid within the lumen.22–24 Small calcifications that are occasionally detected at the periphery and capsule may enhance with contrast. Lesions that abut the bone cause a shallow impression of the bony wall (Figure 25.3).24 In dumbbell-shaped tumors, a bony defect at the frontozygomatic suture can be seen with a small portion of the lesion extending into the fossa temporalis (Figure 25.2).15,25

MR imaging also shows dermoid as a wellcircumscribed lesion that is homogeneous and hy-

pointense to extraocular muscles in T1-weighted images (Figure 25.5). Because of the fat content, however, the signal varies on T1-weighted images, which may show two or more signal intensities within one lesion. The specific nature of the fatty, luminal contents is

FIGURE 25.3. (A,B) Two dumbbell-shaped dermoids (d) located partially in the orbit and partially in the temporal fossa. The widening of the frontozygomatic fissure (arrow) by the expanding dermoid is shown in (A). (C) A chronic inflammatory reaction (arrows) adjacent to a leaking dermoid wall (dw); k keratin.

best demonstrated when diffusion-weighted imaging (DWI) is used, which enables specific definition by signal enhancement.26–29

Small dermoids and epidermoids do not need immediate treatment and can be observed until the second or third year of life and sometimes even longer. However, when the lesion reaches a certain size, it should be surgically removed; whenever possible, removal of these lesions should be conducted with special care to avoid rupture of the cyst wall.11 The surgical removal should be performed before the lesion becomes large enough to displace the eyelid and orbital structures. The growth of the dermoid is primarily due to the increase of its secretions within the lumen, which in turn leads to distension of the cyst wall with focal thinning. The luminal contents may leak out through the weakened areas of the wall and cause chronic inflammatory foreign body reaction. Another issue to consider is that as a child grows and becomes more active, the chance of the dermoids becoming traumatized increases, particularly in the case of the superficial ones. If the lesion is sufficiently large, even a minor trauma may cause the rupture of the tumor with leakage of keratin material into adjacent soft tissues, causing a severe, localized, anaphylactoid reaction. Again, removal should be performed prior to rupture of the cyst, which makes complete excision of the tumor difficult.

Superficial orbital dermoids that are located superiorally can easily be reached through a lid crease incision, which allows good exposure of the tumor, even if it is not located immediately below the lid crease.30,31 Since it is important to remove the dermoid with an intact wall, the surgeon should take time in dissecting around the lesion in a blunt fashion, using cotton tip applicators and blunt curved hemostats to push and spread the adherent soft tissues