Frequency of hypopigmented mycosis fungoides in Egyptian patients presenting with hypopigmented lesions of the trunk.

Hypopigmented mycosis fungoides (HMF) is an uncommon variant of mycosis fungoides with an unknown exact frequency. We aimed to study the frequency of HMF in a cohort of Egyptian patients presenting to a tertiary care center in Cairo, Egypt, with hypopigmented lesions of the trunk. Hundred patients with hypopigmented lesions involving the trunk (with or without other sites involvement) were subjected to thorough clinical and histopathological examination. Immunohistochemical studies (S100, CD4, and CD8) were performed when indicated. Constellation of findings was used to reach a final diagnosis. Sixteen cases had HMF (16%). Other than HMF, our cohort included hypopigmented parapsoriasis en plaque (42 cases), postinflammatory hypopigmentation (28 cases), progressive macular hypomelanosis (12 cases), and pityriasis alba (2 cases). In comparison with other hypopigmented disorders, HMF was significantly associated with progressive disease course (P = 0.004), affection of distal upper limbs (P = 0.005), proximal lower limbs (P = 0.003), large-sized lesions (>5 cm) (P < 0.0001), well-defined margin (P < 0.0001), scaliness (P = 0.002), erythema (P < 0.0001), atrophy (P = 0.012), and mottled pigmentation (P < 0.0001). Awareness of HMF and its characteristic clinical features is mandatory to avoid underdiagnosis or overdiagnosis with subsequent morbidity or unnecessary aggressive therapy, respectively.