mycosis fungoides ( mf ) is the most common subtype of cutaneous t - cell lymphoma ( ctcl ) . mf differs from other primary ctcls by virtue of unique clinical features and histopathology [ 1 , 2 ] . patients with mf commonly present with persistent and/or slowly progressive skin lesions of varying size and shape . the natural history of mf is characterized by an indolent progression through four stages : patch , plaque , tumor , and visceral involvement , but this progression is not necessarily seen in all patients . atypical forms of mf include hypopigmented , hyperpigmented , ichthyosiform , pityriasis lichenoides - like , granulomatous , folliculotropic , bullous , palmoplantar , pagetoid reticulosis , and granulomatous slack skin [ 3 , 4 ] . the peak age at presentation is in excess of 55 to 60 years , with a 2  :  1 male  :  female ratio [ 5 , 6 ] . although mf is a disease mainly seen in older patients , it can be seen in patients under the age of 35 with similar clinical findings [ 7 , 8 ] . the present study thus aimed to produce updated clinical information on iranian mf patients , including epidemiology , patient characteristics , clinicopathologic features , and treatment . between 2003 and 2013 , patients with mf from single - center resident training hospitals had been retrospectively enrolled into the study . a diagnosis of mf was confirmed according to international society for cutaneous lymphoma ( iscl)/eortc criteria [ 1 , 9 ] and , if necessary , based on the proposed algorithm for early phase disease . the analyzed clinical data included the age of the patients at the time of diagnosis , the age of the patients at the time of initiation , the cutaneous lesion , sex , and the status of disease at the last follow - up examination . hematoxylin and eosin - stained slides , immunohistochemical stains for basic b- and t - cell markers ( cd20 and cd3 and/or cd45ro ) , and additional immunostaining , including cd4 , cd8 , cd30 , and cd5 , were histologically evaluated by an expert dermatopathologist . polymerase chain reaction analyses of t - cell receptors ( tcr ) b or c and immunoglobulin heavy chain gene rearrangement were reviewed . in all the patients , the presence of extracutaneous disease at the time of diagnosis had been excluded by standard staging procedures . stage workup ( chest radiology , bone marrow biopsy , computed tomography scan of chest , abdomen , and pelvis ) and overall survival were obtained by reviewing the clinical records . to determine the stage of mf eighty - six patients with clinical and histologic diagnosis of mf were included in the study . table 1 summarizes the demographic profiles and basic data of the 86 patients in our study with mf ( table 1 ) . female predominance was observed in the patients ( male  :  female ratio is 1  :  1.2 ) . the patients with mf were between 7 and 84 years of age ( median : 41 ) . the mean  standard deviation ( sd ) age at the time of skin lesion initiation was 45.02  17.47 and 38.80  16.02 for males and females , respectively . the interval from disease onset to diagnosis ranged from 0 to 55 years ( median : 1 year ) . table 2 summarizes the clinical and histologic variants of the patients with mf ( table 2 ) . at the time of diagnosis , the most prevalent skin lesions were an erythematous scaly patch ( figure 1 ) . from 68 patients with classic mf , 42 patients presented with the patch , 21 with plaque , 4 with a tumor , and only one with erythroderma ( table 2 ) . from 86 patients with mf , the most common types included hypopigmented mf ( figure 1(b ) ) and poikilodermatous mf ( figure 1(c ) ) . other clinical types of mf including pityriasis lichenoides - like lesions , syringotropic , ichthyosiform , and bullous variant were not observed in our patients . hypopigmented skin lesions were seen in 5 ( 5.8% ) patients and included a pure hypopigmented variant in three patients , whereas others had hypopigmented lesions mixed with other types . this group included 4 women and one man , 1534 years of age , at diagnosis ( table 2 ) . the patients with hypopigmented mf were observed to have a younger mean age at diagnosis ( 25.60  7.30 years ) as compared with other mf cases ( 42.52  16.80 years ) . three patients ( 3.5% ) had a solitary mf lesion , whereas others had multiple lesions ( table 2 ) . childhood cases of mf ( younger than 18 years ) constituted 5.8% ( 5/86 ) of all the mf patients . there were two male and three female patients ( male  :  female ratio is 1  :  1.5 ) . none of the patients had hiv or other forms of immunosuppression . according to the tnm classification , among 86 cases of mf , the early stage ( stage i + iia ) included 82 cases ( 95.34% ) and the advanced stage ( stage iib + iii + iv ) included four cases ( 4.66% ) . progression to the late stages of mf is not seen in childhood / juvenile - onset mf patients . cd20 was negative in all patients . in our patients , the conventional t - helper phenotype ( cd4+/cd8 ) was the most common one ( 63% of patients ) ( table 3 ) . a clonal t - cell receptor rearrangement was detected in the skin biopsy in 9 patients ( 36% ) from a total of 25 patients in whom t - cell receptor analysis was possible . antibodies to htlv-1 were not detected in the sera of any patients with mf by elisa . the major differences in the epidemiologic characteristics of mf in isfahan , iran , are lack of male predominance and the lower age of patients at the time of diagnosis in those reported from the west . it was reported that the incidence rate of mf in isfahan is the same as that in other parts of iran , which is largely similar to the data of other countries . mf is generally rare among asians and it has a higher incidence rate in blacks [ 13 , 14 ] ; it can be concluded that immunogenetics or interactions of genetic susceptibility and the environment may have a role in mf incidence . there is a male predominance in almost all studies on ctcls and mf , with a male  :  female ratio of 1.3  :  1 to 2  :  1 [ 1517 ] . the proportion of our patients complaining on the onset of their disease before 21 years was much higher , similar to the epidemiological study in kuwait . the occurrence of mf in younger patients in isfahan , iran , may be related to some ethnic or genetic variations , but the environmental and occupational factors need to be determined . some studies have found an increased incidence of ctcl among workers in chemical science , transportation , and manufacturing industries , whereas other studies have not . hydrocarbons and petrochemical exposure have been reported to carry an increased mf risk [ 20 , 21 ] . whether a greater exposure to chemical agents has some contribution to the course of mf in this region remains to be determined . in the iran - iraq war ( 19801988 ) , it is not known whether chemical weapons by iraq contained sulfur mustard ( sm ) , a dna alkylation , and a well - known carcinogenic agent . this hypothesis can be considered for relatively younger ages of diagnosis among the population in kuwait . the exposure to burning oil during the war contributed to environmental pollution . to evaluate a possibility of pollutants playing a role in the etiology of ctcl , more data needs to be addressed as potential confounders in future studies . the prevalence of childhood mf among different studies has varied between 2.7% and 16.6% [ 23 , 24 ] . in the present study , there was no significant difference in gender in our study in childhood mf . among the atypical forms of mf , hypopigmented mf is overwhelming in asians , with only 16 cases reported as of 2012 in caucasians . compared with other clinical manifestations of mf , the hypopigmented mf is more prevalent in young age groups [ 18 , 25 ] . the reason for the relative high frequency of hypopigmented mf in young patients is not known [ 26 , 27 ] . in agreement with our study , the mean age at diagnosis is lower in the hypopigmented compared with the classic variant [ 28 , 29 ] . on the other hand , the hypopigmented variant was noted in 79% of patients less than 18 years old . our data is compatible with the study of quaglino et al .   in the fact that the current study showed a minority of patients were found to have tumor lesions or erythroderma and extracutaneous involvement . the definitive diagnosis of mf , particularly early stage of disease , is challenging as many of its clinical and pathologic features are nonspecific . the median time from symptom onset to diagnosis in retrospective studies is 3 - 4 years , but it may exceed four decades [ 14 , 32 , 33 ] . the current study differs from that of quaglino et al . in the fact that the median time from the onset of cutaneous lesions to diagnosis was 2 years . in the present study , the mean time from symptom onset to definite diagnosis was about 510 years , which is significantly different in male and female patients . our findings do not support an association between htlv-1 infections and showed that mf does not correlate with htlv-1 infections in isfahan , iran . usually , mf is characterized by an infiltrate of t - helper memory lymphocytes ( cd3 + , cd4 + , cd5 + , cd8 , and cd45ro+ ) . however , in a minority of cases the neoplastic cells exhibit a t - cytotoxic ( cd4/cd8 + ) or a cd4/cd8 double - negative phenotype that shows no clinical and/or prognostic differences . de marchi et al . showed that the coexpression of cd4 and cd8 in patients with mf is associated with a slightly lower rate of progressive disease compared with patients with conventional cd4+/cd8 phenotype . these findings raise the possibility that the coexpression of cd4 and cd8 in cutaneous lesions may confer a better prognosis in mf . the lower tendency of progression of the disease in our patients with the coexpression of cd4 and cd8 might be related to the increased activity of antitumor cd8 + lymphocytes infiltrating the lesions . although the group of this study is really not very large and also the number of the patients with more advanced disease is small , it may be the starting point for a larger multicenter study in iran . whether the occurrence of mf in younger patients in iran is related to some ethnic or genetic variations or to environmental factors needs to be determined . a prospective multicenter study on a larger population of patients with a longer follow - up might be useful to confirm the possible causes of these epidemiological differences .
background . mycosis fungoides ( mf ) is the most common subtype of cutaneous t - cell lymphoma . 
 extensive studies on iranian mf patients are absent . the present study aimed to produce updated clinical information on iranian mf patients . 
 methods . 
 this was a retrospective , descriptive , single - center study , including all cases of mf seen in the department of dermatology , university hospital of isfahan , iran , between 2003 and 2013 . 
 data systematically recorded for each patient included clinical , biological , histological , and molecular findings . results . 
 eighty - six patients with clinical and histologic diagnosis of mf were included in the study . 
 thirty - nine patients ( 45.3% ) were male . 
 female predominance was observed in patients ( male  :  female ratio is 1  :  1.2 ) . 
 patients were between 7 and 84 years of age ( median : 41 ) . 
 the interval from disease onset to diagnosis ranged from 0 to 55 years ( median : 1 year ) . 
 eighteen cases ( 20.9% ) had unusual variants of mf . 
 the most common types included hypopigmented and poikilodermatous mf . 
 childhood cases of mf constituted 5.8% ( 5/86 ) of all patients . 
 the early stages were seen in 82 cases ( 95.34% ) . conclusion . 
 the major differences in epidemiologic characteristics of mf in iran are the lack of male predominance and the lower age of patients at the time of diagnosis .