Chapter Keyword: melanoma

Diagnosis of Eyelid Tumors

The eyelid is the protective shield and the cosmetic, charm of the human eye (see Chapter 2). It consists of, layers of tissue, each of which can give rise to benign and, malignant tumors. This chapter outlines the epidemiology,, differentiating features, and diagnosis of the most, common benign and malignant eyelid tumors (Mind, maps 36-1 to 36-7)., Eyelid cancer constitutes 5%–10% of all skin cancers, the, 4 most common being BCC, SCC, SGCa, and melanoma, (Fig. 36-1). It is important to note that nearly 82%–98%, of all eyelid tumors are benign.1-3 For example, squamous, papilloma, seborrheic keratosis, keratoacanthoma, and, nevi are common benign epithelial tumors of the eyelid., Benign tumors are also more prevalent in the younger, age groups, e.g., dermoid and epithelial tumors comprise, the majority of childhood adnexal tumors.1 Most eyelid, tumors are visible and easily recognized early by the, patient or the parent., Challenges to diagnosis and management include:,

  • Older patients often ignore and delay seeking medical, attention.,
  • Involvement of the lid margin and palpebral conjunctiva, go unnoticed.,
  • Malignant lesions can simulate benign conditions.,
  • The eyelid structures are in proximity with the orbit,, allowing contiguous extension.,
  • The lymphatic and vascular supply of the head and, neck allow potential routes of metastasis.,
  • Extensive surgery with wide margins can result in, unacceptable functional and cosmetic results.

Eyelid tumors can be classified based on tissue of origin, as benign or malignant (Table 36-1). However, in, clinic it is helpful to divide them into melanocytic or, nonmelanocytic (Mind maps 36-1, 36-2). AJCC staging, provides prognostic TNM information that assists, patient management.1,3

Pigmented Conjunctival Tumors

Pigmentation of the conjunctiva is common and may be, benign or malignant. The spectrum of conjunctival pigmented, tumors is broad, ranging from benign acquired, melanosis and conjunctival nevi to more sinister variants, such as melanoma in situ and invasive conjunctival, melanoma.1,2, Conjunctival melanomas can originate spontaneously, from a pre-existing nevus or from primary acquired, melanosis (PAM).33 It is important to note that the 8th, edition AJCC Cancer Staging Manual replaced the term, “primary acquired melanosis with atypia” with “melanoma, in situ.” This was because the former was easily, mistaken for being benign and the latter was consistent, with the nonocular epithelial melanoma nomenclature.1, Further, the AJCC-OOTF advises using PAM only as a, clinical description, as biopsy remains essential for its, differentiation from conjunctival melanoma in situ., Epidemiology of conjunctival melanoma suggests it, most commonly presents in one eye in middle-aged, fairskinned, individuals.3,4 While conjunctival melanoma can, occur in all races, it must be differentiated from naturally, occurring, bilateral, lifelong pigment on the conjunctiva,, termed racial or congenital melanosis.5 Conjunctival, melanomas are rare, comprising approximately 2% of, all ocular tumors and 5% of ocular melanomas.6,7 Nevertheless,, its incidence is increasing and is associated with, a considerable tumor-related risk of mortality.8, However, several pilot studies now suggest that systemic, and advanced local conjunctival melanoma may be treatable, with immunotherapy.9-11, This chapter aims to provide an in-depth understanding, of the varying presentations of pigmented conjunctival, tumors, their differentiation, and appropriate management, (Mind map 39-1). Given the reported recurrence, rates of 12% to 50% after treatment and an overall incidence, of metastasis reaching 26%, there is need for, life-long follow-up and improved treatment options.12,13

Diagnosis of Choroidal and Ciliary Body Melanoma

Extending from the optic disc to the pupillary margin,, the vascular uvea contains melanocytes that can transform, into what is the most common primary intraocular, malignancy in adults, uveal melanoma (UM).1-3 Further,, the uveal layer can be anterior to posteriorly divided into, iris, ciliary body, and choroidal portions. COMS examined, choroidal melanomas and found their average, presenting age to be 60 years; however, uveal melanomas, can occur as early as infancy.1,4,5, Younger patients with choroidal melanoma tend to, have a better prognosis, and it’s thought due to a better, immunological profile.1-3,6 UM incidence is nearly equally, distributed between males and females.1,7 The most common, location of the tumor is the choroid (85%–90%),, followed by the ciliary body (5%–8%) and iris (3%–, 5%).1,2 The annual age-adjusted incidence per million, population is 6.02 for non-Hispanic whites, 1.67 for Hispanics,, 0.38 for Asians, and 0.31 for blacks.8, UMs may arise de novo or from pre-existing uveal nevi., They are also more common in patients with outdoor, occupations, beneath Australia’s ozone hole, on the, sun-exposed lower half of the iris, and in arc welders., This suggests ultraviolet light exposure is a predisposing, factor. However, the etiologic risks of ultraviolet, light exposure have been disputed.9 In addition, several, geographical clusters of UM (primarily affecting, young patients) have been discovered with no identifiable, genetic or environmental factors (e.g., Huntersville,, NC, USA and Auburn, AL, USA).10, UM is not hereditary; however, there have been reports, of familial cases affecting several family members.11, Melanoma is typically a unilateral, unifocal disease, but, cases of primary bilateral or multifocal tumors have been, published.12,13 BAP1 tumor predisposition syndrome has, been associated with an increased risk of developing UM, (2.8% incidence) compared to 0.0061% in the general, population.14,15 Like most cancers, the development of, UM is likely multifactorial.

Prognostication in Uveal Melanoma

Uveal melanoma (UM) has a propensity for metastasis which results in high mortality.1,2 As metastases are rarely detectable at the time of diagnosis, great efforts have been directed toward accurate prognostication and identifying high-risk factors for metastasis.3-5 One can differentiate between clinical, histopathologic, and genetic prognostic factors.6 However, this chapter reveals the breadth of parameters that must be taken into account when trying to predict a patient’s prognosis.7 These include, but are not limited to, the age of the patient, tumor-specific factors, patient comorbidities, the effectiveness of local treatment, and a plethora of tumor-associated mutations and aberrations, all of which influence the risk for metastatic disease.6,8,9