A primary care approach to cutaneous T-cell clymphoma

Nurse Practitioner, Apr 2000 by Macey, William H

ABSTRACT

Approximately 1,000 new cases of cutaneous Tell lymphoma are definitively diagnosed each year.

Mycosis fungoides and Sezary syndrome are the primary lymphomas In this group. Mycosis fungoides can begin in the patch, plaque, or tumor stage or in a combination. Less commonly, its initial presentation is erythrodermic. Because the Initial appearance of cutaneous T-cell lymphoma can be subtle and the histopathologic evidence nonspecific, the disease is commonly misdiagnosed as a common dermatologic condition such as chronic eczema. Misdiagnosis can severely affect treatment and prognosis. Clinicians must be able to recognize this disease and know when to include it in the differential diagnosis. This article provides an overview of cutaneous Tell lymphoma, discusses differential diagnoses, and outlines management considerations.

Cutaneous T-cell lymphoma (CTCL) is a malignant lymphoma that comprises a group of diseases typified by a proliferation of malignant T lymphocytes. The initial presentation is usually dermatologic. These lymphomas are of low grade and should not be confused with other dermatologic lymphomas such as B-cell lymphoma and adult T-cell leukemia/lymphoma.1 Staging and treatment are different for higher-grade lymphomas.

Cutaneous T cell lymphoma, represented primarily by mycosis fungoides (MF) and Sezary syndrome, has several other clinical variants (see Table 1). Although Louis Alibert described the first case of MF in 1806, the National Cancer Institute did not recommend adopting the term cutaneous T cell lymphoma until 1979.2

Cutaneous T cell lymphoma's initial presentation can be subtle. In many cases, the disease mimics common dermatologic conditions such as eczema and psoriasis, and in early stages, histopathologic studies may cloud rather than clarify the picture. According to one study, an accurate diagnosis takes an average of 6 years,z yet delayed diagnosis can affect treatment and prognosis.3

Although single and combined therapeutic drugs can produce prolonged remission, no systemic therapy provides a cure. However, the prognosis for stage IA is excellent.4 Limited early (patch stage) disease is more likely than later stages to respond to steroids.This stage also responds well to topical chemotherapy, psoralen-ultraviolet A (PUVA) treatment, and electron beam therapy, all of which can induce sustained therapeutic response. Early, accurate diagnosis is essential so that therapeutic intervention can begin promptly.

Once the clinician suspects CTCL or obtains confirmatory histopathologic, evidence, the patient should be referred to an oncologist or dermatologist who specializes in cutaneous oncology. Clinicians may continue to serve patients' primary care needs; therefore, they should be aware that disease dissemination can be manifested in any organ system, but this usually occurs in later stages (see Table 2).

Epidemiology

Because a definition of CTCL has not been broadly accepted, epidemiologic data must be viewed with caution. However, there is evidence that the incidence of CTCL has risen markedly.5 This finding is believed to reflect a true increase, not merely scientific advances that permit earlier detection.

Data for 1973 to 1978 show an average incidence of 0.3 cases of MF per 100,000 per year.b Approximately 1,000 new cases are definitively diagnosed in the United States annually. Although CTCL primarily affects older people, 12% of those diagnosed were younger than age 40. The disease occurs in twice as many men as women and is more common in blacks than in whites. No risk factors beyond age, race, and gender have been clearly established.

Clinical Manifestations

Cutaneous T cell lymphoma has four distinct phases: premycotic (patch), infiltrative (plaque), tumor, and erythrodermic (see Figure 1). The phases often overlap.

In the patch phase, CTCL may easily be mistaken for common dermatologic conditions such as chronic eczema and psoriasis (see Figure 2). Sezary syndrome, the erythrodermic, leukemic variant of CTCL, may be confused with such common skin conditions as allergic drug responses (see Figure 3), subacute systemic lupus erythematosus, and erythrodermic psoriasis. A patient's failure to respond to treatment for any of these conditions suggests a possible diagnosis of CTCL, especially in the presence of male sex, black race, or older age.

Mycosis Fungoides

In the patch phase, MF lesions are generally macular and up to several centimeters in size. The lesions usually appear on the trunk, thighs, buttocks, and upper arm but can emerge anywhere on the body Lesions typically resemble benign dermatologic conditions such as chronic eczema, superficial fungal infections, psoriasis, and drug reactions. The patches may appear singularly or in clusters and may or may not be pruritic. Their color may vary from faint pink to yellowish tan to dusky violet-red. The patient may exhibit superficial to mild scaling. The epidermis may appear atrophic.

The patch phase can evolve into the plaque phase over several months to years. In the plaque phase, patches become increasingly dense and more profoundly demarcated. The plaques are elevated, palpable, irregularly shaped, and darker red than patches.