INTRODUCTION Squamous cell carcinoma is a malignant tumor that most commonly affects elderly, fair-skinned individuals. It arises from keratinocytes of the epidermis. Unlike the more common basal cell carcinoma, squamous cell carcinoma tends to arise in precancerous areas of skin alteration or in areas of skin damaged by chronic sun exposure, ionizing radiation, carcinogens (e.g., arsenic), psoralen plus ultraviolet A (PUVA) therapy for psoriasis, and the human papilloma virus. Intrinsic factors that may contribute to its development include xeroderma pigmentosum, oculocutaneous albinism, and immunodeficiency. Chronic skin dermatoses, inflammation, ulceration, and contracted scars also are associated with the development of this tumor. In fact, scarring of the skin is the most common intrinsic factor leading to this tumor in black patients. Lymphatic spread and perineural invasion are possible.
CLINICAL PRESENTATION The most common site of eyelid involvement is the lower lid. Initial changes can look like a chronic eczema-like lesion. The tumor often originates in an actinic keratosis, but tends to be thicker, larger and have a more heaped-up keratinization. These lesions have a tendency to ulcerate, and growth may be endophytic or more exophytic with raised papillary ver-rucous borders. Occasionally it can take on the appearance of a cutaneous horn. Long-standing lesions become friable and bleed easily. Necrosis may follow with superimposed bacterial infection. Orbital extension has been reported in up to 16% of cases. Palpable regional lymph nodes indicate metastatic spread.
HISTOPATHOLOGY The typical squamous cell carcinoma has nests and tongues of squamous epithelial cells that arise from the epidermis and extend into the dermis. Squamous cells are recognizable by their eosinophilic cytoplasm and large nuclei. Keratinization and horn pearl formation are present in tumors that are better differentiated. A mild to moderate infiltrate of lymphocytes around the periphery of the tumor is common.
DIFFERENTIAL DIAGNOSIS The differential diagnosis includes basal cell carcinoma, sebaceous cell carcinoma, Bowen's disease, actinic keratosis, keratoacanthoma, inverted follicular keratosis, papilloma, pseudoepitheliomatous hyperplasia, seborrheic keratosis, trichilemomma, fungal infection, and verruca vulgaris.
TREATMENT Diagnosis requires a biopsy for histologic confirmation. Once the diagnosis is established the goal of therapy is complete removal of tumor cells with preservation of unaffected eyelid and periorbital tissues needed for reconstruction. Mohs' micrographic surgery provides the highest cure rate with the most effective preservation of normal tissue. Excisional biopsy with frozen section control is an acceptable alternative technique. Radiation therapy is generally not recommended as the initial treatment, but it may be useful in the treatment of advanced or deeply invasive recurrent lesions. Doses are in the range of 4000 to 7000 cGy. A recurrence rate of 12% with radiation has been reported. Cryotherapy is often used to treat nonperiorbital lesions, but when applied to the eyelids complications such as marginal notching, ectropion, sympble-pharon formation, fornix foreshortening, and depigmentation of eyelid skin have all been reported. Cryotherapy is also associated with a higher recurrence rate. Advanced cases may be associated with metastasis to the pre-auricular and submandibular lymph nodes, which heralds a more guarded prognosis. Invasion into deep orbital tissues can be seen, often requiring orbital exenteration for definitive management.
Was this article helpful?