Endocrine Abstracts

Background: Sézary syndrome (SS) is a more aggressive leukemic variant of cutaneous T-cell lymphoma (CTCL). Bexarotene (Targretin) is a synthetic rexinoid analogue designed for the treatment of advanced stages of cutaneous manifestations of CTLC. Bexarotene selectively suppresses thyrotropin secretion and up to 40% of patients develop reversible idiopatic central hypothyroidism. Severe mixed dyslipidemia may be present in up to 70%.

Case report: Seventy-year-old female who started development of skin changes on the trunk and limbs at 51 years of age, and 3 years later parapsoriasis in large plates was diagnosed. The evolution of the lesions led to deepening of etiological study, and 2 years later, CTCL in the form of SS, was diagnosed. Multiple treatments were tried without satisfactory clinical improvement. She began bexarotene (Targretin) 300 mg/day in December 2002. Periodic laboratory surveillance, including lipid profile and thyroid function was performed. We detected maximum levels of triglycerides of 618 mg/dl, controlled with antidyslipidemic therapy, and fluctuations in the levels of TSH and free T₄ were mostly compatible with the diagnosis of central hypothyroidism. She was not treated for several years. Fluctuations in values of thyroid function and lipid profile were associated with changes in disease evolution and use of varying doses of bexarotene. She was sent to the consultation of Endocrinology for diabetes mellitus, nodular goiter and assessing need for treatment with levothyroxine. There was need for treatment with levothyroxine and adjustment of oral antidiabetic treatment.

Conclusions: For the rarity of the disease and the endocrine-metabolic consequences of treatment it is important to expose this case. The evaluation of thyroid function and lipid profile should be performed before and during treatment with bexarotene. Dyslipidemia is favored both by treatment with bexarotene and untreated hypothyroidism.