Original Research

Morphology of Mycosis Fungoides and Sézary Syndrome in Skin of Color

Author and Disclosure Information

Although mycosis fungoides (MF) and Sézary syndrome (SS) commonly affect Black patients, dermatologic educational resources primarily describe the appearance of these conditions in lighter skin types. Skin of color (SoC) patients with Fitzpatrick skin types (FSTs) IV to VI tend to have variable morphologies compared to the erythematous patches, plaques, or tumors in non–sun-exposed areas seen in non-SoC patients (FSTs I–III). We performed a single-institution review of clinical photographs of patients with FSTs I to VI with the primary outcome of determining the frequency of various morphologic features of MF/SS in SoC vs non-SoC patients. Providers need to be familiar with the differences in morphologic features across skin types to ensure early diagnosis and treatment.

Practice Points

  • Dermatologists should be familiar with the variable morphology of mycosis fungoides (MF)/Sézary syndrome (SS) exhibited by patients of all skin types to ensure prompt diagnosis and treatment.
  • Patients with skin of color (SoC)(Fitzpatrick skin types IV–VI) with MF/SS are more likely than non-SoC patients (Fitzpatrick skin types I–III) to present with hyperpigmentation, a silver hue, and lichenification, whereas non-SoC patients commonly present with erythema and poikiloderma.



Mycosis fungoides (MF) and Sézary syndrome (SS) are non-Hodgkin T-cell lymphomas that make up the majority of cutaneous T-cell lymphomas. These conditions commonly affect Black patients, with an incidence rate of 12.6 cases of cutaneous T-cell lymphomas per million individuals vs 9.8 per million individuals in non–skin of color (SoC) patients.1 However, educational resources tend to focus on the clinical manifestations of MF/SS in lighter skin types, describing MF as erythematous patches, plaques, or tumors presenting in non–sun-exposed areas of the skin and SS as generalized erythroderma.2 Skin of color, comprised of Fitzpatrick skin types (FSTs) IV to VI,3 is poorly represented across dermatology textbooks,4,5 medical student resources,6 and peer-reviewed publications,7 raising awareness for the need to address this disparity.

Skin of color patients with MF/SS display variable morphologies, including features such as hyperpigmentation and hypopigmentation,8 the latter being exceedingly rare in non-SoC patients.9 Familiarity with these differences among providers is essential to allow for equitable diagnosis and treatment across all skin types, especially in light of data predicting that by 2044 more than 50% of the US population will be people of color.10 Patients with SoC are of many ethnic and racial backgrounds, including Black, Hispanic, American Indian, Pacific Islander, and Asian.11

Along with morphologic differences, there also are several racial disparities in the prognosis and survival of patients with MF/SS. Black patients diagnosed with MF present with greater body surface area affected, and Black women with MF have reduced survival rates compared to their White counterparts.12 Given these racial disparities in survival and representation in educational resources, we aimed to quantify the frequency of various morphologic characteristics of MF/SS in patients with SoC vs non-SoC patients to facilitate better recognition of early MF/SS in SoC patients by medical providers.


We performed a retrospective chart review following approval from the institutional review board at Northwestern University (Chicago, Illinois). We identified all patients with FSTs IV to VI and biopsy-proven MF/SS who had been clinically photographed in our clinic from January 1998 to December 2019. Only photographs that were high quality enough to review morphologic features were included in our review. Fitzpatrick skin type was determined based on electronic medical record documentation. If photographs were available from multiple visits for the same patient, only those showing posttreatment nonactive lesions were included. Additionally, 36 patients with FSTs I to III (non-SoC) and biopsy-proven MF/SS were included in our review as a comparison with the SoC cohort. The primary outcomes for this study included the presence of scale, erythema, hyperpigmentation, hypopigmentation, violaceous color, lichenification, silver hue, dyschromia, alopecia, poikiloderma, atrophy, and ulceration in active lesions. Dyschromia was defined by the presence of both hypopigmentation and hyperpigmentation. Poikiloderma was defined by hypopigmentation and hyperpigmentation, telangiectasia, and atrophy. Secondary outcomes included evaluation of those same characteristics in posttreatment nonactive lesions. All photographs were independently assessed by 3 authors (M.L.E., C.J.W., J.M.M.), and discrepancies were resolved by further review of the photograph in question and discussion.

Statistical Analysis—Summary statistics were applied to describe demographic and clinical characteristics. The χ2 test was used for categorical variables. Results achieving P<.05 were considered statistically significant.

Patient Demographics


We reviewed photographs of 111 patients across all skin types (8, FST I; 12, FST II; 16, FST III; 17, FST IV; 44, FST V; 14, FST VI). The cohort was 47% female, and the mean age was 49.7 years (range, 15–86 years). The majority of the cohort had early-stage MF (stage IA or IB). There were more cases of SS in the SoC cohort than the non-SoC cohort (Table). Only 5 photographs had discrepancies and required discussion among the reviewers to achieve consensus.

Frequency of morphologic features found in skin of color (SoC [Fitzpatrick skin types IV–VI]) vs non-SoC (Fitzpatrick skin types I–III) patients with mycosis fungoides/Sézary syndrome

FIGURE 1. Frequency of morphologic features found in skin of color (SoC [Fitzpatrick skin types IV–VI]) vs non-SoC (Fitzpatrick skin types I–III) patients with mycosis fungoides/Sézary syndrome. Asterisk indicates statistically significant findings (P<.05).

Regarding morphologic characteristics in active lesions (Figure 1), scale was present in almost all patients (99% in SoC, 94% in non-SoC). Erythema was present in nearly all non-SoC patients (94%) but only in 69% of SoC patients (P=.003). Poikiloderma also was found to be present at higher frequencies in non-SoC patients compared with SoC patients (19% and 4%, respectively [P=.008]). However, hyperpigmentation (80% vs 39%), lichenification (43% vs 17%), and silver hue (25% vs 3%) were more common in SoC patients than non-SoC patients (P<.05). There were no significant differences in the remaining features, including hypopigmentation (39% vs 25%), dyschromia (24% vs 19%), violaceous color (44% vs 25%), atrophy (11% vs 22%), alopecia (23% vs 31%), and ulceration (16% vs 8%) between SoC and non-SoC patients (P>.05). Photographs of MF in patients with SoC can be seen in Figure 2.

Representative photographs of mycosis fungoides (MF) in skin of color (Fitzpatrick skin types [FSTs] IV–VI)

FIGURE 2. Representative photographs of mycosis fungoides (MF) in skin of color (Fitzpatrick skin types [FSTs] IV–VI). A, A female with FST IV and MF (stage IA) who presented with hypopigmented and hyperpigmented (dyschromic) erythematous patches with poikiloderma and overlying scale on the chest and neck. B, A female with FST V and MF (stage IB) who presented with erythematous to violaceous lichenified plaques with overlying scale along the back and buttocks. C, A female with FST V and MF (stage IB) who presented with hyperpigmented, violaceous, and lichenified patches and plaques with an overlying silver hue and scale diffusely distributed along the back and buttocks. D, A female with FST V and MF (stage IB) who presented with hypopigmented scaly patches on the abdomen. E, A male with FST VI and MF (stage IIB) who presented with hyperpigmented and violaceous lichenified patches, plaques, and tumors with an overlying silver hue and scale on the thighs.


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