Cutaneous T-cell lymphoma: a review

Cutaneous T-cell lymphomas define a spectrum of disorders associated with T-lymphocytic proliferation with clinical manifestations occurring in the skin during the course of the disease. This review has dealt with two rather uncommon disorders, namely mycosis fungoides and Sezary syndrome which are indolent malignant lymphomas, occurring primarily in the fifth decade, and affecting males most frequently. Historically, mycosis fungoides and Sezary syndrome have been described for a relatively short time. As witnessed by Table 2, little was known concerning these disorders, other than clinical and pathologic features, until the application of immunologic, cell biologic, and cytogenetic technology which burgeoned a multitude of questions. The discovery of TCGF has allowed for both continuous growth of normal and neoplastic T cells and for the clonal expansion of some malignant clones. The establishment of these continuous cultures allowed for: (1) investigation of the mechanism of TCGF production and stimulation of T-cell growth, and (2) identification of HTLV, a retrovirus found in cell cultures from two patients with CTCL, and subsequently from patients with Japanese adult T-cell lymphoma. In addition, the HTLV has been related to a more virulent form of T-cell malignancy. The exact etiologic role of this virus in the CTCL is presently the subject of intense investigation. Through the use of immunologic methods the malignant cell of CTCL has been pheno-typically and functionally characterized as a "helper/inducer" subtype (E rosette+, anti-T-cell antisera+, T11+, T1+, T3+, 3A1-, T6-, T8-) and usually Ia-, HLADR-. Clinical manifestations of the phenotype may be clinically apparent in the serologic abnormalities present in these disorders. Utilizing these methods to investigate these disorders may provide a key to the understanding of T-cell function and cellular immunity much as myeloma provided a model for the understanding of B cells and immunity. Clinically and pathologically, these disorders behave as malignant indolent lymphomas with spread from localized cutaneous lesions to extracutaneous involvement of the blood, lymph nodes, and viscera culminating in the death of the patient from either organ dysfunction or infectious complications. At autopsy, this extracutaneous involvement is more pronounced than what was expected ante-mortem. Application of prospective staging techniques employing such special procedures as E-rosette cytology, cytogenetics, and electron microscopy in addition to usual light microscopy studies has demonstrated a greater percentage of extracutaneous involvement than otherwise expected.(ABSTRACT TRUNCATED AT 400 WORDS)