Clinicoepidemiological features of mycosis fungoides in Kuwait, 1991-2006.

BACKGROUND: Mycosis fungoides (MF) is an indolent, most common type of cutaneous T-cell lymphoma (CTCL) with an average estimated incidence of 0.5 cases per 100,000 persons per year in the western world. Although various clinical and epidemiological features are well delineated in the western population, the data is scarce from our region.

OBJECTIVES: To study the clinicoepidemiological features of MF from Kuwait.

SETTING: A referral photobiology unit for cutaneous lymphomas in a national dermatology department in collaboration with three other dermatology departments in Kuwait and Kuwait cancer center.

PATIENTS AND METHODS: One hundred and ninety-three cases of MF registered between July 1991 and June 2006 were included for this study.

RESULTS: Eighty-six percent of our MF cases were of Arab ethnicity. Males outnumbered the females by 2:1 ratio. Mean age at diagnosis was 35.20 ± 14.37 years, and 16% of the patients were diagnosed by the age 20 years. The annual incidence rate (IR) of MF in Kuwait was observed to be 0.43 cases per 100,000 persons with a significantly higher IR among Arabs as compared to non-Arab Asians (RR = 4.4; 95% CI = 2.9-6.6). A successive rise in the IR of MF was noticed with the advancing age. The annual IR among males was more or less comparable to that of females. Skin patches were the most prevalent skin lesions (67%) at diagnosis, and 22% of the patients had a pure hypopigmented variant. Patients with hypopigmented MF were observed to have younger mean age at diagnosis (27.60 ± 12.42 years) as compared to other MF cases (38.14 ± 14.37 years) (P = 0.000). Ninety-two percent of the patients had the early stage (IA, IB, and IIA) of disease.

CONCLUSIONS: Our patients with MF were observed to have a relatively younger age at diagnosis, with a high proportion of patients diagnosed by the age 20 years. Arabs were observed to have a higher annual IR of MF as compared to non-Arab Asians. Hypopigmented MF is prevalent in our population. The study highlights the ethnic and/or regional variations in the clinicoepidemiological characteristics of MF.