11 Management of Malignant Eyelid and Periocular Tumors

10.1055/b-0039-171454

11 Management of Malignant Eyelid and Periocular Tumors

Abstract

“Management of Malignant Eyelid and Periocular Tumors” discusses the many different treatment modalities that have been advocated, by a variety of medical practitioners, for the management of malignant tumors in the periocular region. It is essential to select the treatment modality best suited to the needs of the individual patient. The management of all malignant eyelid tumors depends on correct histological diagnosis, assessment of tumor margins, and assessment of local and systemic tumor spread. The selected treatment modality must be capable of totally eradicating all tumor cells to which it is applied, and there must be a mechanism to ensure that the treatment is applied to all the existing tumor cells. Tumors of the eyelids and canthi often exhibit slender strands and shoots of cancer cells that can infiltrate the local tissues beyond the clinically apparent borders of the tumor. Most malignant periocular tumors are basal cell and squamous cell carcinomas, for which the gold standard is Mohs’ micrographic surgery. The follow-up of patients with periocular malignant tumors is very important and depends on a number of variable factors.

11.1 Introduction

Many different treatment modalities have been advocated, by a variety of medical practitioners, for the management of malignant tumors in the periocular region. It is essential that the treatment modality best suited to the needs of the individual patient is selected.

The management of all malignant eyelid tumors depends on

Correct histological diagnosis.
Assessment of tumor margins.
Assessment of local and systemic tumor spread.

Most malignant periocular tumors are nonmelanoma cutaneous malignancies (basal and squamous cell carcinomas). Other malignant periocular tumors are much less common:

Sebaceous gland carcinoma.
Melanoma.
Merkel cell tumor.
Metastatic eyelid tumor.
Lymphoma.
Kaposi’s sarcoma.
Angiosarcoma.
Microcystic adnexal carcinoma.
Primary mucinous carcinoma.

There are two major considerations in selecting a treatment for these tumors:

The selected treatment modality must be capable of totally eradicating all tumor cells to which it is applied.
A mechanism must exist to ensure that the treatment is applied to all the existing tumor cells.

Tumors of the eyelids and canthi often exhibit slender strands and shoots of cancer cells that can infiltrate the local tissues beyond the clinically apparent borders of the tumor. For this reason appropriate monitoring to ensure that the treatment modality reaches all of the tumor cells is essential. Numerous studies have demonstrated that clinical judgment of tumor margins is inadequate, significantly underestimating the area of microscopic tumor involvement. The introduction of frozen-section control to document adequacy of tumor excision marked a major advancement in the treatment of the common malignant eyelid tumors and now constitutes the standard of care. Any treatment modality that does not use microscopic monitoring of tumor margins must instead encompass a wider area of adjacent normal tissue in the hope that any microscopic extensions of tumor will fall within this area.

There are two goals in the surgical management of malignant eyelid tumors:

Complete eradication of the tumor.
Minimal sacrifice of normal adjacent tissues when possible.

These concepts are of the utmost importance in the surgical management of periocular malignancy because of the complex nature of the periocular tissues and the functional importance of the eyelids in ocular protection, in addition to the grave risks that are posed by tumor recurrence in this area.

Mohs’ micrographic surgery represents the gold standard in the management of basal cell and squamous cell carcinomas.

In the periocular region, focal malignancy can be treated with any of the following:

Surgery.
Irradiation.
Cryotherapy.
Photodynamic therapy (PDT).
Topical chemotherapeutic agents.

The choice of therapy depends on several factors:

The size of the tumor.
The location of the tumor.
The type of tumor.
The age and general health of the patient.
The outcome of discussions at a dedicated cancer multidisciplinary team meeting (MDT).

The choice of treatment is particularly important in certain circumstances:

Diffuse tumors.
Tumor extension to bone or the orbit.
Patients with a cancer diathesis, such as the basal cell nevus syndrome.
Young patients.

Key Point

Mohs’ micrographic surgery represents the gold standard in the management of basal cell and squamous cell carcinomas.

A comprehensive examination of the patient is important, with palpation of the regional lymph nodes and a whole body skin examination if possible. If orbital invasion is suspected from the clinical examination, as in restriction of ocular motility, it is appropriate to request thin-section, high-resolution computed tomography (CT) with bone windows. In selected cases, chest and abdominal CT is required with liver function tests to evaluate systemic spread. Such patients should be managed in conjunction with an oncologist. If systemic spread is found, palliative therapy only may be preferable.

The follow-up of patients with periocular malignant tumors is very important and depends on a number of variable factors. A protocol for this should be set up by clinicians involved in the management of these patients.

11.2 Basal Cell Carcinoma

Unfortunately, basal cell carcinomas have traditionally been regarded as relatively benign, rarely invasive tumors by many different clinicians in a variety of specialties and as such have commonly been casually excised. This has been associated with a high incidence of recurrence, unnecessary morbidity, and occasionally avoidable mortality. A dedicated approach to tumor eradication is clearly essential in the management of patients who have a basal cell carcinoma. The main options for the management of these tumors in the periocular area include the following:

Surgery in conjunction with histological monitoring of tumor margins.
Irradiation.
Cryotherapy.
PDT.
Topical chemotherapeutic agents.
Oral chemotherapy.

The surgical management of basal cell carcinoma consists of surgical removal of the tumor, with monitoring of the excised margins, either by formalin-fixed, paraffin-embedded, or frozen section control. A close working relationship with a specialist pathologist offers a major advantage in the efficient delivery of such care. In most cases the diagnosis is evident on clinical grounds alone. If the diagnosis is unclear, a biopsy should be performed before definitive treatment. For small well-defined tumors, an excisional biopsy with a 2- to 3-mm margin serves not only to establish the histological diagnosis but also as a definitive treatment if the excision margins prove to be clear. Mohs’ micrographic surgery is now considered by many to represent the gold standard in the management of periocular basal cell carcinomas, particularly for poorly defined or critically sited tumors. Unfortunately, this treatment modality is unavailable in many centers in this and other countries. Where Mohs’ surgery is not available, so-called “slow Mohs’” techniques have evolved using formalin-fixed, paraffin-embedded sections with delayed reconstruction of the periocular defect with good outcomes and low recurrence rates. Standard frozen section control may be required for patients who require surgery under general anesthesia (e.g., patients with extensive periocular tumors and dementia). It is important to orient the specimen using sutures of varying length, and a tumor map should be recorded for the pathologist, such as, “The long silk suture marks the lateral aspect of the excision, the short suture the superior aspect, and the intermediate suture the medial aspect.”

Although it is reasonable to close small defects immediately, no defect should be formally reconstructed without definitive histopathological evidence of complete tumor clearance. Exenteration is reserved for cases in which orbital invasion has occurred and aggressive surgical management is appropriate for the individual patient.

Surgery continues to be the main treatment modality for the management of periocular basal cell carcinomas, but it should be recognized that new pharmacological agents, such as immunomodulators, topical chemotherapeutic agents, and PDT, have emerged and have shown some promising results. PDT, usually undertaken by a dermatologist, may have a role to play in small superficial basal cell carcinomas in patients with basal cell nevus syndrome (Gorlin’s syndrome).

Radiotherapy and cryotherapy also have their own limited role to play in the management of periocular basal cell carcinomas.

Key Point

A tumor defect should not be formally reconstructed, except by simple direct closure if appropriate, until definitive histopathological evidence of complete tumor removal has been obtained.

11.2.1 Irradiation

Historically, irradiation as a treatment modality for periocular cutaneous malignancies was very popular in the United Kingdom, and a number of studies reported better than 90% cure rates for periocular basal cell carcinomas. More recently, however, investigators have noted that basal cell carcinomas treated by irradiation recur at a higher rate and behave more aggressively than tumors treated by surgical excision.

The radiation dose used to treat patients varies, depending on the size of the lesion and the estimate of its depth. The treatments are usually fractionated over several weeks, depending on local protocols. The proponents of radiation therapy point to the lack of discomfort with radiation treatment and to the fact that no hospitalization or anesthesia is required.

Although radiation therapy is no longer to be recommended as the treatment of choice for periocular cutaneous malignancies, some patients, for various reasons, cannot undergo surgical excision and reconstruction; for these patients irradiation may be useful. However, it is important to continue to look closely for evidence of recurrence well beyond the 5-year postoperative period routinely used for surgically managed cutaneous malignancies.

Disadvantages

It is now generally accepted that basal cell carcinomas recurring after radiation therapy are more difficult to diagnose, present at a more advanced stage, cause more extensive destruction, and are much more difficult to eradicate. The greater extent of destruction may be explained by the presence of adjacent radiodermatitis, which may mask underlying tumor recurrence and allow the tumor to grow more extensively before it can be clinically detected (Fig. 11‑1). The damaging effect of radiation on periocular tissues poses another drawback to its use.