The clinical presentation and diagnosis of skin cancer in organ transplant recipients is generally similar to that in nonimmunosuppressed patients. However, as detailed elsewhere in this book, transplanted patients may have more numerous, severe, and life-threatening tumors. This chapter will discuss the clinical characteristics of the most common types of tumors seen in organ transplant recipients (OTRs) and will briefly highlight aspects that are unique to transplant patients where they exist. Each major tumor type will be discussed in greater detail, including treatment options, in subsequent chapters.

Table 22.1 summarizes common terms used to describe the clinical appearance of dermatologic lesions. These terms will be used throughout this chapter and in other chapters of the book.

ACTINIC KERATOSIS

(FIGURE 22.1–FIGURE 22.4)

Actinic keratosis (AK) is a proliferation of atypical keratinocytes confined to the epidermis, with the potential to progress to invasive squamous cell carcinoma (SCC). The vast majority of AKs are induced by UV radiation and their incidence increases with age, degree of UV exposure, and lighter skin pigmentation. There is some controversy with regard to whether AK should be considered a premalignant neoplasm or the earliest form of in situ SCC. Due to the risk of progression, AKs should be treated with curative intent.

Clinically, AKs present as rough, scaly papules on sun-exposed skin. They are often difficult to appreciate by visual inspection and are more easily recognized by the identification of rough sandpaper-like patches on light palpation of the skin.